Title of Invention	A BONNET LOCK MECHANISM FOR A BLOWOUT PREVENTER, A BLOWOUT PREVENTER AND A METHOD FOR SECURING A BONNET TO A BODY OF A BLOWOUT PREVENT
Abstract	The present invention relates to a bonnet lock mechanism for a blowout preventer comprising: a radial lock; a radial lock displacement device; and at least one lock actuator operatively coupled to the radial lock displacement device, wherein the radial lock displacement device is adapted to radially displace the radial lock to form a locking engagement between a bonnet and a body of the blowout preventer. The present invention also relates to a method for securing a bonnet to a body of a blowout preventer

Title of Invention

A BONNET LOCK MECHANISM FOR A BLOWOUT PREVENTER, A BLOWOUT PREVENTER AND A METHOD FOR SECURING A BONNET TO A BODY OF A BLOWOUT PREVENT

Abstract

The present invention relates to a bonnet lock mechanism for a blowout preventer comprising: a radial lock; a radial lock displacement device; and at least one lock actuator operatively coupled to the radial lock displacement device, wherein the radial lock displacement device is adapted to radially displace the radial lock to form a locking engagement between a bonnet and a body of the blowout preventer. The present invention also relates to a method for securing a bonnet to a body of a blowout preventer

Full Text	QUICK RELEASE BLOWOUT PREVENTER BONNET Background of Invention Field of the Invention Ths invention relates generally to blowout preventers used in the oil and gas industry. Specifically, the invention relates to a blowout preventer with a nc»vel bonnet securing mechanism. Background Art Wd[\ control is an important aspect of oil and gas exploration. When drJIing; a well in, for example, oil and gas exploration applications, devices must b£: put in place lo prevent injury to personnel and equipment associated with the drilling activities. One such well control device is known as a blowout preventer (BOP). Blowout preventers are generally used to seal a wellbore. For example, drilling wells in oil or gas exploration involves penetrating a variety of subsurface geologic structures, or "layers/^ Each layer generally comprises a spe;cific geologic composition such as , for example, shale, sagdstone,, limestone^ etc. Each layer may contain trapped fluids or gas at different fornation pressures, and the formation pressures increase with increasing depth. Tlie pressure in tl}e wellbore is generally adjusted to at least balance the fonnatioTii pressure by, for example, increasing a density of drilling mud in the wellbore or increasing pump pressure at the surface of the wdU There are occasions during drilling operations when a wellbore may penstrate a layer having a formation pressure substantially higher that the pressure maintained in the wellbore. ^Vhen this occurs, the well is said to have 'taken a kick." The pressure increase associated with the kick is generally produced by an influx of formation fluids (which may be a liquid, a gas, or a ^.Dnibination thereof) into the wellbore. The relatively high pressure kick tends [0 propagate from a point of entry in the wellbore uphole (from a high pressure region to a low pressure region). If the kick is allowed to reach the surface, drilling fl uid, well tools, and other drilling structures may be blown out of the wellbore.. These ^'blowouts" often result in catastrophic destruction of the drilling equipment (including, for example, the drilling rig) and in substantial itijury or death of rig personneL Eiecause of the risk of blowouts, blowout preventers are typically installed at tlie surface or on the sea floor in deep water drilling arrangements sc that lacks may be adequately controlled and 'circulated out" of the system. Blowout preventers may be activated to effectively seal in a wellbore until active rneasures can be taken to control the kick. There arc several types of blowouit preventers, the most common of which are annular blowout preventers and ram- type blowout preventers. j .^nnulcir blowout preventers typically comprise annular elastomer "packer:/' rJiat may be activated (e.g., inflated) to encapsulate drillpipe and well tools and completely seal the wellbore- A second type of the blowout preventer is the ram-type blowout preventer. Ram-type preventers typically comprise a body and lat least tvi^o oppositely disposed bonnets. The bonnets are generally secured to the body about their circumference with, for example, bolts. Allemaii'/ely, bonnets may be secured to the body with a hinge and bolts so that the bonnet may be rotated to the side for maintenance access. ^ I Interior of each bonnet is a piston actuated ram. The rams may be either pips rams; (which, v/hen activated, move to engage and surround drillpipe and well tools to seal the wellbore) or shear rams (which, when activated, move to engage and physically shear any drillpipe or well tools in the wellbore). The rarns are typically located opposite of each other and, whether pipe rams or sheiir rams, the rams typically seal against one another proximate a center of the wellbore in order to completely seal the wellbore. M with any tool used in drilling oil and gas wells, blowout preventers must be regularly maintained- For example, blowout preventers comprise high piessure seals between the bonnets and the body of the BOP. The high pressure seals in many instances are elastomer seals. The elastomer seals must be regularly checked to ensure that the elastomer has not been cut, peraianently deformed, or deteriorated by, for example, chemical reaction with the drilling fluid ill the wellbore. Moreover, it is often desirable to replace pipe rams with shear rams, or vice versa^ to provide different well control options. Therefore, it is important that the blowout preventer includes bonnets that are easily reraovaible so that interior components, such as the rams, may be accessed and maintained ][)eveloping blowout preventers that are easy to maintain is a difficult task- For example, as previously mentioned, bonnets are typically connected to the BOP body by bolts or a combination of a hinge and bolts. The bolts must be highly torqued in order to maintain a seal between a bonnet door and the BCiP body. The seal between the bonnet and the BOP body is generally a face seal, and the seal must be able to withstand the very high pressures present in the wellbore. I As a result, special tools and equipment are necessary to install and remove ihe bonnet doors and bonnets so that the interior of the BOP body may be acce£;sed. The time required to install and remove, the bolts connecting the bornet doors to the BOP body results in rig downtime, which is both expensive and inefficknt. Moreover, substantially large bolts and a nearly complete bolt circle" sround the circumference of the bonnet door are generally required to provide jiufficient force to hold the bonnet door against the body of the BOP, The size of the bolts and the bolt circle may increase a "stack height" of the BO?. It is common practice to operate a "stack" of BOPs (where several BOPs are inst Several attempts have been made to reduce stack height and the time required to access the interior of tlie BOP. U.S. Patent No- 5,655,745 issued to Morrill shows a pressure energized seal carrier that eliminates the face seal between the bonnet door and the BOP body. The BOP shov/n in the "745 patent enables the use of fev/er, smaller bolts in less than a complete bolt circle for securing the bonnet to the body. Moreovex, the 745 patent shows that a hinge may be used in place of at least some of the bolts. U.S. Patent No. 5,897,094 issued to Brugman et al discloses an irnproved BOP door connection that includes upper and lower connector bars for securing bonnets to the BOP, The improved BOP door connection of the 'C'94 patent does not use bolts to secure the bonnets to the BOP and discloses a d Summary of Invention In one aspect^ the invention comprises a bonnet lock mechanism for a blowout preventer. The bo^imet lock mechanism comprises a radial lock, a radial lock displacement device, and at least one lock actuator operatively coupled to the radial lock displacement device. The radial lock displacement device is adapted to radially displace the radial lock to a form flocking engageniient between a bonnet and a body of the blowout preventer. In another aspect, the invention comprises a bonnet lock mechanism for a tlowc»iit preventer comprising a bonnet door operatively attached to a swivel slide moimt The swivel slide mount is adapted to slide in relation to a body of the blov/ont preventer. At least one lock actuator is coupled to the bonnet door, and a radial lock displacement device is operatively coupled to the at least one lock actjator. The bonnet is adapted to be slidably positioned proximate a side opening of ^ihe body of the blowout preventer. Tlie at least one lock actuator is adapted to axially displace the radial lock displacement device so as to radially d. splace aradial lock to fonti a locking engagement between the bonnet and the body cif the blowout preventer. In another aspect, the invention comprises a bonnet lock mechanism for a blowout preventer comprising a radial lock disposed in a body of the blowout preventer. At least one lock actuator is operatively coupled to the radial lock. The at least one lock actuator is adapted to radially displace the radial lock so that an internal surface of the radial lock forms; a locking engagement with a bonnet, In another aspect, the invention comprises .a blowout preventer comprising a body, and a bonnet cooperatively attached to the body proximate each of ar. least two oppositely disposed side openings formed in the body. A radial locking mechanism is cooperatively attached to each bonnet and is adapted to secure each bonnet to the body proximate an inner perimeter of the at least rwo side openings. hi another aspect, the invention comprises a bonnet seal adapted to form a sealing engagement between a bonnet and a body of a blowout preventer. In a:nother aspect, the invention comprises a method for securing a bonnet to a body of a blowout preventer. The method comprises positioning the bonnet proximate a side opening of a body of the blowout preventer, activating at.least one lock actuator operatively coupled to a radial lock disjDlacement device, axially displacing the radial lock displaceipent device, and: radially displacing the radial lock with the radial lock displacement device so as to foim a locking engagement between the bonnet and the body of the blowout preventer. In another aspect, the invention comprises a method for securing a bonnet to a body of a blowout preventer. The method comprises positioning the bonnet proximate a side opening of a body of the blowout preventer, activating arleast one lock actuator operatively coupled to a radial lock, the radial lock disposed in the body of the blowout preventer, and radially iisplaciiig the radial lock so as to form a -locking engagement between the bonnet and the body of the blowout preventer Other aspects and advantages of the invention will be apparent from the following description and the appended claims. Brief Description of Drawings Figure 1 f;hows a partial section and exploded view of a BOP comprising an embodiment of the invention. FiE^ure 2 shows an enlarged view of a portion of the embodiment shown ir Figure L Figure 3 shows an embodiment of a radial lock displacement device. Fi^re 4 shows another embodiment of a radial lock displacement device. Figure 5 shows an embodiment of the invention where a radial lock is pinned to a portion of a bonnet. Figure 6 shows an embodiment of a radial lock comprising two halves. Figure 7 shows an embodiment of a radial lock comprising four segments- Figiure 8 shows an embodiment of a radial lock comprising a plurality of se,?merit!5. . ► ]Figure 9 shows an embodiment of a notched serpentine radial lock, ]"igure 10 shows an embodiment of a locking mechanism used in an embodiment of the invention. Ingure 11 shows an embodiment of a locking mechanism used in an embodiment of the invention. Figure 12 shows an embodiment of a locking mechanism used in an embodiment of the invention. Figure 13 shows an embodiment of a high pressure seal used in atp n-ibodiment of the^ invention-Figure 14 shows an embodiment of a high pressure seal used in an :;mbodin:ient of the invention. FigTire 15 shows an embodiment of a high pressure seal used in an ^inbod'iment of the invention. Figure 16 shows an embodiment of a high pressure seal used in an embodiment of the invention. Figure 17 shows an embodiment of a high pressure seal used in an embodiment of the invention. Figure 18 shows an embodiment of the invention wherein a radial lock is disposed in a recess in a side passage of a BOP body. Figure 19 shows an embodiment of a radial lock comprising two halves. J'igure 20 shows an embodiment of a radial lock comprising four scj^ient::;. Figure 21 shows an embodiment of a radial lock comprising a plurality of kerfs. Figure 22 shows an erabodiment of a radial lock comprising graduated kenfs. f'igure 23 shows a. side perspective view of an embodiment of a swivel slide mount used in an embodiment of the invention. Figure 24 shows a front perspective view of an embodiment of a swivel slide mount used in an embodiment of the invention. Figure 25 shows a top perspective view of an embodiment of a swivel slicie mc'unt used in an embodiment of the invention. Detailed Descriptio0 An embodiment of the invention is shown in Figure 1. A ram-type blowout preventer (BOP) 10 comprises a BOP body 12 axjd oppositely disposed bonnet assemblies 14. The BOP body 12 further comprises couplings 16 (v/hich may be, for example, flanges) on an upper surface and a lower surfa(iB of the BOP body 12 for coupling the BOP 10 to, for example, another BOP or to another well tooL The BOP body 12 comprises an internal bore 18 therethrough for the passage of drilling fluids, drillpipe, well tools, and the like Lsed to drill, for example, an oil or gas well. The BOP body 12 further comprises a plurality of side passages 20 wherein each of the plurality of side passages 20 is generally adapted to be coupled to a bonnet assembly 14. The bonnet assemblies 14 are coupled to the BOP body 12, typically in opposing pairs as shown in Figure 1. Each bonnet assembly 14 further comprises a plurality of components adapted to seal the bonnet assembly 14 to the BOP body 12 and to activate a ram piston 22 within each bonnet assembly 14. Components of the bonnet assembUes 14 comprise passages therethrough for movement of the ram piston 22. Each bonnet assembly 14 generally comprises similar components. ^ ' s * V/hile each bonnet assembly 14 is a separate and distinct part of the BOP 10, the operation and structure of each bonnet assembly 14 is similar. Accordingly, in order to simpliiy the description of the operation of the BOP 113 an bonnet assembly 14 will be (^escribed in detail It should be understood that each bo'nnet assembly 14 operates in a similar manner and that, for example, opposing bonnet assemblies 14 typically operate in a coordinated manner. Proceeding with the description of the operation of one bonnet assembly 1A[, the piston 22 is adapted to be coupled to a ram (not shown) that may be, for e:x.ampie, a pipe ram or a shear ram. Each ram piston 22 is coupled to a ram actuatc-r cylinder 24 that is adapted to displace the ram piston 22 axially within the bo:met assembly 14 in a direction genenilly peipendicular to an axis of the BOP body 12, the axis of the BOP body 12 being generally defined as a vertical a>:is of tlie internal bore 18 (which is generally parallel with respect to a wellbore axis), A ram (not shown) is generally coupled to the ram piston 22, and, if the rams (not shown) are shear rams, the? axial displacement of the ram piston 22 generally moves the ram (not sho^vn) into the internal bore J8 and into contact with a corresponding ram (not shown) coupled to a ram piston 22 in a bonnet assembly 14 disposed on an opposite side of the BOP 10. Alternatively, if the rams (not shown) are pipe rams, axial displacement of the lam piston generally moves the ram (not shown) into the internal bore 18 and ini:o contact v/ith a coitesponding ram (not shown) and with drillpipe and/or wdl tools present in the wellbore. Therefore, activation of the ram actuator cylinder 24 displaces the ram piston 22 and moves the ram (not shown) into a position to. block a flow of drilling and/or formation fluid thi'ough the internal bore 18 of the BOP body 12 and, in doing so, to form a high pressure seal that prevents fluid flow from passing into or out of the we^llboie (not shown), 71ie ram actuator cylinder 24 further comprises an actuator 26 which s tmy be, f:)r example, a hydraulic actuator, Hov/ever^ other types of actuators are known in the art and may be used with the invention. Note that for purposes of the description of the invention, a "fluid" may be defined as a gas, a liquid, or i combination thereof For example, if the ram {not shown) is a pipe ram, activation of the ram piston 22 moves the ram (not shown) into position to seal around drillpipe (not shcwTi) or well tools (not shown) passing through the internal bore 18 in the BOP body 12. Further, if the ram (not shown) is a shear ram, activation of the ram piston 22 moves the ram (not shown) into position to shear any drillpipe (not shoWTi) or well tools (not shown) passing through the internal bore-18 of the BOP body 12 and, therefore, seal the internal bore 18. .Radial Lock Mechanism for Comlin^ Bonnets to BOPs ATiimportant aspect of a BOP 10 is the mechanism by which the bonnet assemblies 14 are sealed to the body 12, Figure 1 shows a radial lock niech£;nism 28 that is designed to provide a high pressure radial seal between the bonnet assembly 14 and the BOP body 12. Moreover, the radial lock niechani::;m 28 is designed to simplify maintenance of the bonnet assembly 14 and the rams (not shown) positioned therein. ; In the embodiments shown in the Figures, the side passages 20 and other components of the BOP 10 designed to be engaged therewith and therein are shown as being oval or substantially elliptical in shape. An oval or substantially elliptical shape {e.g., an oval cross-section) helps reduce the stack hdght of the BOP, thereby minimizing weighty material used, and cost. Other shapes such as circular shapes, however, are also suitable for use with the invention- Accordingly, the scope of the invention should not be limited to the shapes of the embodiments shown in the Figures, The radial lock mechanism 28 is positioned within the bonnet assembly i4 and within the side passage 20 of the BOP body 12. In this embodiment, the radial lock mechanism 28 comprises a bonnet seal 29 disposed on a bonnet s body 30,, a radial lock 32, a radial lock displacement device 34, a bonnet door 36, and lock actuators 38. The bonnet seal 29 cooperatively seals the bonnet body 30' to the BOP body 12 proximate the side passage 20. The bonnet seal 29 compnses a high pressure sea] that prevents fluids from the internal bore 18 of the BOP body 12 fromi»escaping via the side passage 20. Various embodiments of the bonnet seal 29 will be discussed in detail below. When the bonnet seal 29 is fomied between the bonnet body 30 and the BC»P body 12, the bonnet body 30 is in an installed position and is located proxim^ite the BOP body 12 and at least partially within the side passage 20, Bec^ause: the bonnet seal 29 is a high pressure seal, the radial lock mechanism 23 inii:r>t be robust and able to withstand Very high pressures present in the interna] bore 18. Tlie embodiment shown in Figure 1 comprises a novel mechanism for Icckingthe^bonnet assembly 14 (and, as a result, the bonnet seal 29) in place, ReferriBg to Figure 2, the radial lock 32 has an inner diameter adapted to fit over an exterior surface 40 of the bonnet body 30 and slide into a position adjacent a sealing end 45 of the bonnet body 30- The radial lock 32 shown in Figure 2 comprises two halves separated by a center cut 46. However, the radial iDck 32 niay comprise additional segments and the two segment embodiment shown in Figure 2 is not intended to ■ limit the scope of the invention.. Additional embodiments of the radial lock 32 will be described in greater detail below. The radial lock displacement device 34 also has an inner diameter adapted to fit over the exterior surface 40 of the bonnet body 30, Moreover, tl-ie radiial lock'displacement device 34 fiirther comprises a wedge surface 48 on an external diameter that is adapted to fit inside an inner diameter 50 of the radial Ictck 32, The.radial lock displacement device 34 also comprises an inner fac:e 56 that is adapted to contact an outer surface 54 of the BOP body 12. In an insts.lled position, the bonr^et body 30, the radial lock 32, and the r^ial lock displacement device 34 are positioned between the BOP body 12 and the bonnet door 36. An inner surface 52 of tl-ie boimet door 36 is adapted to contact the outer surfade 54 of the BOP body 12. Note that the'engagement between the bonnet door 36 and the BOP body 12 is not fixed (e.g., the bonnet door 36 is not bolted to the BOP body 12). The boimet .assembly 14 is adapted to slidably engage at least one rod 70 through a swivel slide mouni; 74 (note that two rods 70 are shown slidably engaged,, through the swivel slide mounts 74, with each bonnet assembly 14 in Figure 1). As a result of the slidable engagement, the bonnet assembly 14 may slide along the rods 70. As will be discussed below, the slidable engagement .penn:its the bonnet assembly 14 to be move^d into and out of locking and sealiiig engagement with the BOP body 12. The lock actuators 38 are coupled to the bonnet door 36 with either a fixed or removable coupling comprising bolts, adhesive, welds, tlireaded connections, or similar means known in the art. The lock actuators 38 are also cooperatively coupled to the radial lock displacement device 34 in a similar fashion. Additionally, the coupling between the lock actuators 38 and the radial lock displacement device 34 may be a simple contact engagement. Note tliat tlie embodiments in Figure 1 shows two lock actuators 38 coupled to each bonnet door 36. However, a single lock actuator cylinder 38 or a plurality of lock actuators 38 may be used with the invention. The lock actuators 38 shown are generally hydraulic cylinders; however, other types of lock actuators (includmg, for example, pneumatic actuators, electrically powered motors^, and tlie like) Eire known in the an: and may be used with the invention. Mloreover, the lock actuators 38 may also be manually operated. The lock aciluators 38 shown in the present embodiment are typically controlled by, for example, an external electrical signal, a flow of pressurized hydraulic fluid, etc. AiS an alternative, the radial lock 32 may be activated by manual means, such a;3, for example, a lever, a system of levers, a threaded actuation^device, lor oiher similar means known, in the art. Further, if, for example, the lock actuators 38 comprise hydraulic cylinders, the hydraulic cylinders may be activated by a manual pump- Accordingly, manual activation of the radial lock 32 is \\'ithin the scope of the invention. A jully assembled view 15 of the bonnet assembly 14 including the iidial lock mechamsm 28 is shown in Figure 2. During operation of the radial lock nriechanism 28, the bonnet assembly 14 is first moved into position proximate the BOP body 12 by sliding the bonnet assembly 14 toward the BOP body 1:2; on the rods 70- The lock actuators 38 are then activated so that they ajcially displace (wherein an axis of displacement corresponds to an axis of the side passage 20) the radial lock displacement device 34 in a direction toward the BOP body 12. As the radial lock displacement device 34 moves axially toward the BOP body 12, the wedge surface 48 contacts the inner diameter 50 oJ'the radial lock 32, thereby moving the radial lock 32 in a radially outward directi \A^iien the radial lock 32 is secured in place by the activation of the lock acTuators; 38. and the.radial lock displacement device 34, the bonnet body 30 and the bonnet assembly )4.a:re axially .locked in place with respect toihe BOP body 12 without the use of, for example, bolts. However, an additional manual locking mechanism (not shown) may also be used in combination with the inventicm. to ensure that'the radial lock 32 remains securely in place. Once the radial lock 32 is secured in place by, for example, hydraulic actuation, a manual lock (not shown), such as a pinned or threaded mechanism, may be activatecl as an additional restraint. The secured radial locking mechanism 28 is designed to hold the bonnet assembly 14 and, accordingly, the high pressure bonnet seal 29 in place. The radial lock 32 and the high pressure bonnet seal 29 can vwithstand the high forces generated by the high pressures present within the internal bore 18 of the BOP body 12 because of the locking engagement )etwKeii the radial lock 32 and the inner radial lock surface 58 of the BOP body 12- The radial lock mechanism 28 may be disengaged by reversing the •.ctivatioB of the lock actuators 38 (e.g., after the pressure in the internal bore 18 has bec: relieved)- As a result^ the invention comprises a radial lock r.Liechanism 28 that includes a positive disengagement system (e.g., the lock actuators 38 must be activated in order to disengage the radial lock mechanism 28). The wedge surface 48 used to radially displace.the radial lock 32 may comprise any one of several odiments. Referring to Figure 3, in one embodjrnentj the wedge surfa.. ^5 of the radial lock displacement device 34 may comprise a single actuation step 80, In another embodiment shown in Figure 4, the wedge surface 48 may comprise a dual actuation step 82. Note that the single actaation step (80 in Figure 3) generally has a shorter actuation snroke than the dual actuation step (82 in Figure 4). Further^ an actuation step angle (S4 in Figures 3 and 4) is designed to maximize a radial actuation force and minimize a linear actuation force. In one embodiment of the invention, the acjtuatio-n step angle (84 in Figures 3 and 4) is approximately 45 degrees. In aiiiothe:! embodiment of the invention, the actuation step angle (84 in^Figures'S and 4) is less than 45 degrees. In another embodiment shown in Figuie 5, the radial lock displacement device 34 further comprises a slot 90 and at least one retention pin 92 designed to retain the radial lock 32 against the load shoulder 44 of the bonnet body 30. In this embodiment, the radial lock 32 is retained in place by the at least one retention pin 92, and the bonnet body 30 and the radial lock 32 are held in a filled relationship after the radial lock 32 has been actuated and is in locking engagement with die inner radial lock surface (58 in Figure 2) of the side passage (20 in Figure 1), The radial lock (32 in Figure 1) may also comprise any one of several jmbodin-ients. The radial lock 32 shown in the embodiment of Figure 1 :ompnses tv/o radial mixrored halves 94, 96, ais further shown in Figure 6, In ■mother embodiment, as shown in Figure 7, a radial lock 100 may be formed from at least tv/o substantially linear segments 102 and at least two semicircular end segments 104, In another embodiment, as shown in Figure 8, a radial lock 106 may be formed from a pluraliiy Of substantially straight dogs I. [)8 and a plurality of curved dogs 110. The embodiments shown in Figures 7 and 8 essentially comprise radial locks 100,106 similar to the radial lock (32 in Figure^! 1 and 6) of the first embodiment but divided into a plurality of segments. The. radial locks 100^ 106 could be manufactured by, for example, rranufacturing a solid radial lock and sequentially saw cutting the solid radial Icck into two or more segments. However, other manufacturing techniques are kjiown in the art and may be used to manufacture the radial lock-In another embodiment shown in Figure 9,. a radial lock 112 may be formed fi:om a notched serpentine structure 114 similar to a "serpentine belt/* The racbal lock 112 is formed, for example, as a single solid piece and-then cut 117 through an inner perimeter 113 or an outer perimeter 116, The cuts 117 can either completely transect the radial lock 112 or may include only partial cuts. Further, if the cuts 117 transect the radial lock 112, the individual segmetits can be attached to a flexible band US so that the radial lock 112 can be actuated with an actuating ring (34 in Figiire 1). The flexible band 118 may comprise a material with a relatively low elastic modulus (when compared to, fo* example, the elastic modulus of the individual segments) so that the flexible band 118 can radially expand in response to the radial displacement produced by the radnal lock displacement device (34 in Figure 1). Radial expansion of th The engagement between the radial lock (32 in Figure 1) and the inner radial lock surface (58 in Figure 2) may also comprise different embodiments. In ons embodiment, as shown in Figure 10, a radial lock 120 may comprise a single profile engagement including a single radial lock engagement surface 122. The single radial lock engagement surface 122 is designed to lockingly engage a BOP engagement surface (59 in Figure 2) formed on the inner radial lock surface (58 in Figure 2) of the side passage (20 in Figure 1). In another embodiment, as shown in Figure 11, a radial lock 124 comprises a dual profile engagement including two radial lock engagement irarfaces 126. Moreover, the radial lock 124 may also comprise a plurality of radial lock engagement surfaces designed to lockingly engage a corresponding number of BOP engagement surfaces (59 in Figure 2) formed on the inner radial lock surface (58 in Figure 2) of the side passage (20 in Figure 1) of the BOP t>ody (12 in Figure 1). I The radial locks described in the referenced embodiments are designed so thsLt the cross-sectional area of engagement between the radial lock engagement surfaces with tlie BOP engagement surfaces (59 in Figure 2) is maximized- Maximizing the cross-sectional areas of engagement ensures that tihe radial locks positively lock the bonnet assembly (14 in Figure l)Aand, as>a result, the bonnet seal (29 in Figure 1) in place against the high pressures present in the internal bore (18 in Figure 1) of the BOP (10 in Figure I). Moreover, as discussed previously, angles of the engagement surfaces may be designed to produce an axial force that finnly pulls the bonnet door (36 in Fi]^re 1) against the BOP bo^dy (12 in Figure I) and that in some embodiments may assist in the activation of the bonnet seal (29 in Figure 1). lilt:) radial locks and the engagement surfaces described in the foregoing embodiments may be coated with, for example, hardfacing materials and/or friction reducing materials. The coatings may help prevent, for example, galling, and may prevent the radial locks from sticking or "hanging-up" in the engagement surfaces during the activation and/or deactivation of the radial lock niechanism (28 in Figure 1), The coatings may also increase- the life of the radial locks and the engagement surfaces by reducing friction and wean Another embodiment of the lock ring 127 is shown at 127 in Figure 12. The radial lock 127 comprises a plurality of saw cuts 128, a plurality of holes 129, ox a combination thereof. The saw cuts 128 and/or holes 129 decrease the weight and area moment of inertia of the radial lock 127, thereby reducing the actuation force required to radially displace the radial lock 127. In-order to pr.rmit some elastic deformation of.the radia] lock 127, the radial lock 127 may bci fonned from a materia.1 having a relatively low modulus of elasticity (when cc»mpared to, for example, steel).. Such materials comprise titanium, beryllium copper, eic. Moreover, modifications to the radial lock 127 geometry, in addition to those referenced above,, may be made to, for example, further reduce the area.moment of inertia of the radial lock 127 and reduce bending stresses. The: radial locks described above are designed to operate below an elastic limit of tlie materials, from which they are fonned. Operation below the elastic limit ensures that the radial locls will not permanently deform and, as a rcimlt of the permanent deformation, lose effectiveness. Accordingly^ material selecticm. and cross-sectional area of engagement of the engagement surfaces is very important to the design of the radial lock mechanism (28 in Figure 1). Referring to Figure 1, the bonnet seal 29 is designed to withstand the high pressures present in the. internal bore IS of the BOP body 12 and to thereby prevent fluids and/or gases from passing from the internal bore 18 to the; exterior of the BOP 10. The bonnet seal 29 may comprise several different configurations as shown in the following discussion of Figures 13-17. Moreover, the seals disclosed in the discussion below may be formed from a vaiiety of materials. For example, the seals may be elastomer seals or non-elastomer seals (such as, for e;icample,.metal seals, PEEK seals, etc.). Metal seals may further comprise metal-to-metaj C-ring seals and/or metal-to-metal lip seals- Further, the sealing arrangements shown below may include a combination of seal types and materials. Accordingly, the type of seal, number of seals, and the material used to form radial and face seals are not intended to limit the bonnet seal 29. The embodiment in Figure 13 comprises a bonnet seal 130 formed on a radial perimeter 132 of a bonnet body 133, The radial seal 130 further c;omprises two o-rings 134 disposed in grooves 136 formed on the radial perimeter 132 of the bonnet body 133. The o-rings 134 sealingly engage an inner sealing perimeter 138 of the side passage (20 in Figure 1) in the BOP body 12. The embodiment shown in Figure 13 comprises two grooves 136, but a single j^roove or a plurality of grooves may be suitable for use with the o-rings 134, Moreover, while the embodiment shows two o-rings 134, a single o-ring or more than two o-rings may be used in the invention. In another embodiment shown in Figure 14, a bonnet seal 140 comprises at lea£;i: tv/o packing seals 146 (which may be, for example^ t-seals, lip seals, or ssals Isold under the trademark PolyPak, which is a mark of Parker HannijQn, Ji]K.) In another embodiment shown in Figure 15, the bonnet seal 152 comprises a radial seal 154 disposed in a groove 166 formed on a radial perimeter 160 of a bonnet body 162. Moreover, the embodiment comprises a face seal 156 disposed in a giroove 164 formed on a mating face surface 168 of ths boime:it body 162, The radial sea] 154 is adapted to sealingly engage an inner sealing perimeter 158 of the side passage (20 in Figure 1) of the BOP oody 12. The face seal 156 is adapted to sealir-gly engage an exterior face 170 of the BOP body 12. The radial seal 154 and face seal 156 shown in the embodiment are-both-o-rings and are disposed in single grooves 166, 164, However, a different type of seal (such as, for example, a packing seal) and more thain one seal (disposed in at least one groove) may be used with the invention. In another embodiment shown in Figure 16, the bonnet seal 172 compiises a radial seal 174 disposed in a giroove 178 formed on a seal carrier 180. The seal carrier 180 is disposed in a gi'oove 182 formed in a bonnet body 1:54 and also comprises a face seal 176 disposed in a groove 177 foinied on the seal carrier 180. The face seal 176 is adapted to sealingly engage mating face surface 186 of the BOP body 12, and the radial seal 174 is adapted to sealingly engage an inner sealing perimeter 188 fomied in the bonnet body 184. The bonnei; seal 172 may also comprise an energizing mechanism 190 that is adapted to displace.the seal carrier 180 in a direction toward the exterior surface 186 of the BOP body 12 so as to energize the face seal 176. The energizing mechanism 190 may comprise, for example, a spring, a thrust washej; or a similar structure- s The energi2:ing mechanism 190 helps ensure that the face seal 176 maintains positive contact with and, thus, maintains a high pressure seal with the exterior surface 186 of the BOP body 12, However, the energizing mechanism 190 is not required in all embodiments. For example, the seal carrier 180 may be designed so that both the radial seal 174 and the face seal 176 are pressure activated v/ithout the assistance of an energizing mechanism 190. In the embodiment without an energizing mechanism, a diameter and an a>cial thiicliiness of a seal carrier (such as the seal carrier 180 shown in Figure 16) are selected so that high pressure from the interna,] bore first moves the seal oatrier toward the exterior surface of the BOP body. Once the face seal sealingVy engages the exterior surface, the high pressure from the intemal bore causes the seal carrier to radially expand until the radial seal sealingly engages ■#-■ the groove in the seal carrier. A similar design is disclosed in U-S. Patent No. !5,255,890 issued to Morrill and assigned to the assignee of the present invention. The 890 patent clearly describes the geometry required for such a s;eal can'ier. hi the embodiment shown in Figure 16, the face seal 176 and the radial seal 174 may be, for example^ o-rings, packing seals, or,any other high pressure seal known in the art. Moreover, Figure 16 only shows single seals disposed in single grooves. However, more than one seal, more than one groove, or a combination thereof may be used with the invention. In another embodiment shown in Figure 17, the seal carrier 192 as shown in the previous embodiment is used in combination with a backup seal 194 disposed in a groove 196 on an external surface 198 of a bonnet body 200. Ihe backup seal 194 may be an o-ring, a pricking seal, a metal seal, or any other high pressure seal biown in the art. The backup seal 194 further iriaintainj; a liigh pressure seal if, for example, there is leakage from the seals disposeid on the seal carrier 192. Note that the embodiment shown in^igure 17 does not include an energizing mechanism. Advaritageously, some of the seal embodiments reduce an axial force n In another embodiment of the radial lock shown in Figure 18, the radial lock mechanism 220 comprises a radial lock 222 disposed in a recess 224 fonned on an intemal surface 226 of a side passage 228 of a BOP body 230, Tlie operation of the radial lock mechanism 220 differs from the embodiments described above in that securing a bonnet body 232 and/accordingly, a bonnet door (not shown) and a bonnet assembly (not shown), in place iis accomplished by actuating the radial lock mechanism 220 in radially inward direction- The structure of the embodiment shown in Figure 18 is similar to the strucUEie of the embodiments described above except for the direction of actuation of the radial lock mechanism 220. Therefore, the discussion of the present embodiment will include a description of how the alternative radial lock mechanism 220 differs from those shown above. Common elements of the embodiments (such as, for example, the bonnet door 36, the linear rods 70, etc.) will not be described again in detail. Moreover, it should be noted that the embodiment of Figure 18 does not require, for example, actuator cylinders or a radial lock displacement device (e.g., the embodiment of Figure 18 does not require an internal actuation mechanism). I Actuation of the radial lock 222 is in a radially inward direction. Accordingly, the radial lock 222 must be coupled to an actuation mechanism tliat differs from, for example, the radial lock displacement device (34 in Figure ]) and the lock actuators (38 in Figure 1) described in the previous er-tbodiments- In one embodiment of the invention, the radial lock 222 ccmprises a structure similar to those shown in Figures 6 and 7. As shown in Figure 19, separate halves 236, 238 of the radial lock 222 may be cougled to radially positioned actuators 240. When the bonnet body 232 is moved jnto a sealing engagement with the BOP body 230, the actuators 240 are activated to diisplace the halves 236, 238 of the radial lock 222 in a radially inward dii-ectioTi, jio that the radial lock 222 engages a groove (244 in Figure 18) foimed on an exterior surface {246 in Figure 18) of the bonnet body (232 in Figure 18). The radial lock mechanism (220 in Figure IS) locks the bonnet body (^132 in Figure 18) and, therefore, the bonnfet door (not shown) and the bonnet assembly (not shown) in place and energizes the high pressure seal (234 n Figure 18). Note that the high pressure seal (234 in Figure 18) may be rormed from any of the embodiments shown above (such as the embodiments lesciibed with respect to Figures 13-17). Moreover, the radial lock 222 and ;he groove 244 may comprise angled suri^ces (as disclosed in previous embodiments) that produce an axial force that pulls the bonnet body 232 (and [he bonnet assembly (not shown) and bonnet door (not shown)) toward the BOP body 230 and forther ensure a positive loddng engagement. Moreover, as shown in Figure 20, the radial lock 222 may comprise more than two parts. If a radial lock 250 comprises, for example, four parts ^152, 254, 256, 258, an equal number of actuators 240 (e.g., four) may be used to acmate the radial lock 250. Alternatively, fewer actuators 240 (e.g., less than four in the embodiment shown in Figure 20) may be used if an actuator. 240 is;, for example, coupled to more than one part parts 252, 254, 256, 258 of tie radiial lock 250, The acituators 240 may be hydraulic actuators or any other t/pe :tf actuator known in the art. Moreover, the actuators 240 may be disp05;c.d within the BOP body (230 in Figure 18) or may be positioned external to the BOP body (230 in Figure 18). The actuators 240 may be coupled to the radial Jock 250 with, for example, mechanical or hydraulic linkages (not sliowr). On another embodiment^ the radial lock 222 comprises a j^urality of dies or dogs (not shown) tliat are coupled to and activated by a plurality of actuators (not shown). In another embbdiment of the invention shown in Figure ^1, a radial Icck 270 may be formed from a single segment 272. The radial lock 270 is actuated by circumferential actuators 274 coupled to the radial lock 270 and disposiid proximate ends 276, 278 of the segment 272. When activated, the circumferential actuators 274 move the ends 276, 278 of the segment 272 towards; each other and in a radially inward direction as shown by the arrows in Figure 21. The dashed line in Figure 21 represents an inner surface 277 6f the raiiial lock 270 after actuation. The radial lock 270, when actuated, engages tlic bonnet body (232 in Figure 18) in a manner simikr to tliat shown in Figure 18- ^riie segment 272 of rJie radial lock 270 may be produced by forming a plurality of kerfs 284 proximate the end segments 280,282, The kerfs 284 may be desrigned to ease installation of the radial lock 270 in the recess (224 in Figure 18) and to improve flexibility for radial deformation of the radial lock 270, The kerfs may be of any shape kjiown in Ihe art: For example, Figure 22 shows rectangular kerfs 284. However, the kerfs 284 may preferably be formed in a manner that reduces stress concentrations, or stress risers at the edges of the kerfs 284. For example, if the kerfs 284 are formed as rectangular stiapes, stress risers may fonn at the relatively sharp comers. Accordingly, the ktirfs 284 may comprise filleted comers (not shown) or, for example, substantially trapezoidal shapes (not shown) to minimize the effects of stress nsers. Moreover, the kerfs 284 may be "graduated,' as shown in Figure 22, to produce ti substantially smooth transition be'tv^^een relatively stiff straight segments 286 and relatively flexible end segments 280, 282. Graduation of the ksrfs 284 effects a smooth stiffiiess transition that helps prevent stress risers at th(5 last kerf (e.^^, at the last kerf proximate the straight segments 286).^ rhe radial lock 270 may be formed from a single material or from different materials (comprising, for example, steel, titanium, beryllium copper, * * or combinations and/or alloys thereof). For e^xample, the curved end segments 280, 282 may be fomied froi?i a material that is relatively compliant when compared to a relatively rigid material fomiing the straight segments 286 (e.g., thei curved and segments 280,. 282 may be formed from a material with an elastic modulus (Ec) that is substantially lower than.an.elastic modulus (Es) of the^ straight segments 286). R.egardless of the materials used to form the radial lock 27D, the radial lock 270 must be flexible enough to permit installation into and removal from the recess (224 in Figure 18). Altemativdyj the radial lock 270 of Fi;?ure 21 may comprise more than one sej?rnent (e.g., two halves or a plurality of segments) coupled to and actuated by a phrality of circumferential actuators- The radial lock 270 may also comprise a plurality of separate dies or dogs coupled by a flexible band. The dies may be separated by gaps, snd the distance of separation may be r»elec ted to provide a desired flexibility for the radial lock 270, The dies and the flexible banding may comprise different materials. For example, the dies may be formed from a substantially stiff material (e.g., a material with a relatively high modulus of elasticity) comprising, for example, steel or nickel based alloys. The flexible banding, in contrast, may be foraied from materials having a relatively lower modulus elasticity and comprising, for example, titanium alloys or pultmded flats or shapes comprising fiberglass, carbon fibers, or composite materials thereof. As described above, the radial locks of the embodiments own in Figures 19-22 may be coated with, for example, hardfacing nniate.:als (comprising^ for example, tungsten carbide, boron nitride, and similar materials knov^n in the art) or low-friction materials (comprising, for example, polytetrafluoroelhyle^ne and similar materials known in the siri;) to, for example, reduce friction and wear and improve the longevity of the parts. The material composition of the radial lock 270 is not intended to be limiting. The embodiments shown in Figures 19-22 may be advantageous because of a r€Jduced bonnet assembly weight and accordingly, reduced overall weight of the BOP. Moreover, there is a potential to retrofit old BOPs to include the rfi.dial lock mechanism. SM^IVCI Slide Mount for Bonnet Assemblies Refening again to Figure 1, another important aspect of the invention is the swivel slide mounts 74 cooperatively attached to fhe rods 70 and to each of the bc^iiBct assemblies J4. As described previously herein, the bonnet assemblies 14 are coupled to the swivel slide mounts 74, and the swivel slide fnounts 74.are slidably engaged with the rods 70. The swivel slide mounts 74 ' Eire a(3apted to allow.the bonnet assemblies 14 to rotate proximate their axial c^entedmes so that the rams (not shown) and the interior components of bodi the bonnet assemblies 14 and the BOP body 12 may be accessed for rAainlenancej to change the rams, etc. AJI embodiment of the swivel slide tDOunt 74 is shown in Figures 23 and 24. The swivel slide mount 74 comprises a swivel slide mounting bar 76 and a swivel plate 78. The swivel slide mounting bar 76 is slidably attached to the rods 70. The slidable attachment between the swivel shde mounting bar 76 and tlie rods 70 may be made with, for example, linear bearings 87 that are coupled to the sw/ivel slide mounting bar 76. However^ other shdable attachments known m the ait may be used with the invention to form the sHdeable attachment. Moreover, bushings (not shown), or a combination of linear bearings 87 and bushings (not shown) may be used with the invention. The SA'ivel. plate 78 is rotationally attached to the sv/ivel slide mounting bar 76 and is cooperatively attached to an upper surface 75 of the bonnet assembly 14. The cooperative attachment of the swivel slide mount 74 to the bonnet a;;semb'Jy 14 is made substantially at an axial centerline of the bonnet assembly '■■ . • 'llie rods 70 are designed to be of sufficient length to permit the bonnet assembly 14 to disengage from the BOP body 12 and slide away from the BOP body 12 luintil the ram *(not shown) is completely outside the side passage 20, ^^Lo^eovfir, a point of attachment 82 where the swivel slide mount 74 is cooperatively attached to the upper surface. 75 of the bonnet assembly 14 may be optimized so that the point of attachment 82 is substantially near a center of mass of the bonnet assembly 14. Positioning the point of attachment 82 substanticilly near the center of mass reduces tlie force required to rotate the bc>nnet assembly 14 and also reduces the bending stress experienced by tie svwel nlate 78. The swivel plate 78 may further include a bearing 85. For example, the bearing 85 may be cooperatively attached to the swivel slide mounting bar 76 and adapted to witlistand both radial and thrust loads generated by the rotation of the bonnet assembly 14. The bearing 85 may comprise, for example, a combination radial bearing and thrust bearing (such as, for example, a tapered roller bearing). Alternatively, the bearing 85 may comprise, for example, a roller bearing to support radial loads and a thrust washer to support axial loads. tlowever, other types of bearing arrangements are known in the art and may be used with the swivel plate 78. )) When the ram (not shown) is completely out of the side passage 20, the bonnet assembly 14 can rotate about a rotational axis of the swivel plate 78 so that the ram (not shown) and the side passage 20 may be accessed for maintcjnance, inspection, and the like. In the embodiment shown in Figures 23 itnd 24, the lower bonnet assembly 14 is shown to be rotated approximately 90 degrees wth respect to the BOP body 12 while the upper bonnet assembly 14 remains: m locking engagement with the BOP body 12. A ram block attachj-nent point 80 is clearly visible. I] Figoire 25 shows a top view of the BOP 10 when one of the bonnet aEsembhes 14 has been disengaged from the BOP body 12 and rotated approximately 90 degrees. As shown, the ram block attachment point 80 is clearly visible and may be vertically accessed. Vertical access is a significant advantage because prio^ art bonnets that include hinges generally pivot about an edge of the bormet door. Therefore, if, for example, a lower BOP bonnet was unbolted and pivoted open, the ram could not be vertically accessed because the body of the upper BOP bonnet was in the way. Vertical access to the ram is important because it makes it much easier to maintain or replace rams, tlios reducing the time required to maintain the BOP and increasing the level of safety of tlie personnel performing the ifhaintenance. Further, vertical access; enables, for example, maintenance of a lower BOP bonnet while an i3pper boimet is locked in position (see, for example.. Figures 23-25). The bonnet assembly 14 may also be rotated approximately 90 degrees bi the other direction with respect to an axis of the side passage (20 in Figure 1), thereby permitting approximately 180 degrees of rotation. However, other embodiment may be designed that permit rotation of greater than or less than 180 dci^i^rees. The range of rotation of the swivel slide mount 74 is not intended to Hm:t the scope of the invention. The swivel slide mount 74 advantageous because-of the simplicity of the design and attachment to the bonnet assembly 14. For example, prior art h: nges are generally complex, difficult to manufacture, and relatively expensive. Further, prior art hinges have to be robust because they carry the full w«!:ight of the BOP bonnet about a vertical axis positioned some distance aAvay from the center of ma;£:s of the bonnet. The bending moment exerted on the hinge is, as a result, veiy high and dcfonriation of the hinge can lead to "s aggi]i g" of the bonnet. While the invention has been described with respect to a limited number of embodiments, those skilled in the art, having benefit of this disclosure, will appreciate that other embodiments can be devised which do not depart from the scope of the invention as disclosed herein. Accordingly, the scope of the invention should be limited only by the attached claims. What is claimed is: Jcl] • A boiinef lock mechanism for a blowout preventer cornprising: a ladial lock; a radial lock displacement device; and at least one lock actuator operatively coupled to the radial lock displacement device, v^hereiii the radial lock disp>lacement device is adapted to radially displace the radial lock to fonn a locking engagement between a bonnet and a body of the blowout preventer. [cl] I'he t'onnet lock mechanism of claim 1, wherein an external surface of the radial look is adapted to fonn a locking engagement with an intemal surface of a side opening of the body of the blowout preventer. [c:51 The bcamet lock mechanism of claim 1, wherein the radial lock comprises two radially mirrored halves. [C'll The bonnet lock mechanism of claim 1, wherein the radial lock comprises a p'uralily of radial lock segments, }c5] The boi]inet lock mechanism of claim 4, wherein the plurality of r^ial lock sc:gmeniLS are cooperatively attached to a flexible band. '-:tij T.ie bonnet lock mechanism of claim 5, wherenn the flexible band is formed from £1 material having a lower modulus of elasticity than a material from v/hich tlie plurality of radial lock segments are formed. tl] The bonnet lock mechanism of claim 2, wherein the external surface of the rajial Hock comprises at least one radial lock engagement surface adapted to form a locking engagement v/ith at least one radial engagement surface formed on the internal surfi^ce of the side opening. The bonnet lock mechanisiB of claim 7, wherem the at least one radial lock engagement surface and the at least one radial engagement surface comprise fiagagement angles of approximately 45 degrees. The bomet lock mechanism of claim 7, wherein a cross sectional area of the locking engagement is maximized- The bonnet lock mechanism of claim 1, fiirther comprising a bonnet seal. The bonnet lock mechanism of claim 10, wherein the bonnet seal further comprises at least one radial seal adapted to sealingly engage an inner radial sealinji surface of the side opening. The bonnet lock mechanism of claim 10, wherein the bonnet seal comprises at least one face seal adapted to sealingly engage'an inner face sealing sxirface of the side opening. Ttie bonnet lock mechanism of claim 10, wherein the bonnet seal fiirther comprises: a seal carrier ring disposed within a groove foraied on an interior end of the bonnet body; at least one radial seal disposed in a groove foimed on a radi£il surfdfce of the issal carrier ring and adapted to sealingly engage a radial sealing surface of the groove on the bonnet body; and at leasi: one face seal disposed in a groove fonncd on an interior surface of the si^:il.carrier ring and adapted to seahngly engage a face sealing surface of the side opening. The bonnet lock mechanism of claim 1, v^herein formation of tlie locking engagement moves a bonnet door into a contact engagement with the body. The bc-nnet lock mechanism of claim 1, wherein the radial lock comprises a hardfac:ing material lt:16] rbe bonnet lock mechanism of claim 1, wherein the radial lock comprises a friction reducing material, (cl71 The bonnet lock mechanism of claim 2, wherein the internal surface of the side opening comprises a hardfacing material [t:l8) The Ixmnet lock mechanism of claim 2, wherein the internal surface of the side openiiiig comprises a friction reducing material., [cl9] The bonnet lock mechanism of claim 1, further comprising a bonnet door coupled to the bonnet, wherein the at least one lock actuator is cooperatively attached to the bonnet door. [tlO] The bonnet lock mechanismi of claim 2, wherein the at least one lock actuator is £idaptE;d to axially displace the radial lock displacement device. I<::21 a bonnet lock mechanism for blowout preventer comprising> £. bonnet door opexatively attached to a bonnet and to a swivel slide mount, the swivel slide mount adapted to slide in relation to a body of the blowout preventer; at leaiit one lock actuator coupled to the bonnet door; a radial lock displacement device operatively coupled to the at least one lotk actuator; and a radial lock, ^^herein the bonnet is adapted to be slidably positioned proximate a side opening of the body of the blowout preventer, and the at least one lock actuator is adapted to axially displace the radial lock displacement dei^ce so as to radially displace ttie radial lock to form a locking engagement between the bonnet and the body of the blowout preventer. fc22] The bonnet lock mechanism of claim 21 ,,wherein the bonnet is adapted to slide in relation to the body of the blowout preventer along a line parallel to an axis oftheiside opening. ic2;31 llie bDKnet lock mechanism of claim 21, wherein the at least one lock actuator is coupled to an external surface of the bontjet door, the lock actuator being adapted to pass through an opening in the bonnet door and operatively engage the radial lock displacement device. [c;;4] The bonnet lock mechanism of claim 21, farther comprising a bonnet seal. [clS] The bonnet lock mechanism of claim 24, wherein the bonnet seal is adapted to scalingly engage an interior seahng surface of the side opening. [tUy] The bonnet lock.mechanism of claim 21, wherein an external surface of the ntdial ]ock displacement device comprises a wedge surface including at least one actuation step, \|c;!7] The bonnet lock mechanism of claim 26, wh&rein the at least one actuation step comprises an actuation step angle of approximately 45 degrees. [c:;i8J Tie bonnet lock mechanism of claim 26, wherein the at least one actuation step comprises an actuation step angle of less than 45 degrees. \|ic:.;9J Tlie bonnet lock mechanism of claim 21, wherein the radial lock is slidably attached to the radial lock displacement device. lc:iOI A bonnet lock mechanism for a blowout preventer comprising: a ::adial lock disposed in a body of the blowout preventer; and at least one lock actuator operatively coupled to the radial lock, wliereir.1 the at least one lock actuator is adapted to radially displace the radial k)ck so that an internal surface of ttie radial lock forms a locking e-ngagement with a bonnet positioned in a side opening of the body of the blowout preventer. :31\| Thie bonnet lock mechanism of claim 30^.\vherem the radial lock comprises at least C'lie segment, the at least one segment comprising at least one substantially straight segment and at least two curved segments. t32] The iD'Onnet lock mechanism of claim 31, v^erein the at least two curved segments comprises a plurality of kerfs. t331 iTie bonnet lock mechanism of claim 32, wherein the kerfe comprise substantjially rectangular shapes. c34] iTie bonnet lock mechanism of claim 32,, wherein the kerfs comprise siibst£Liitially trapezoidal shapes. [c3f;] TTie bonnet lock mechanism of claim 31, wherein the at least one substantially s'Taiglit segment is formed from a different material than a material forming the at least two curved segments. [c361 The bonnet lock mechanism of claim U wherein the at least one lock actuator is ci:>upled to the bonnet. c::(7) The bonnet lock mechanism of claim 1, wherein the at least one lock actuator is coupled to a bonnet door that is coupled to the bonnet, t:S] T^ie bc>nnet lock mechanism of claim 37, wherein the at least one lock actuator is; coufiled to an exterior surface of the bonnet door, c39\| Tlie bcmncrt lock mechanism of claim 1, wherein the at least^one lock actuator ccmpriseii: a hydraulic actuator. !:40]\| The bonnet lock mechanism of claim 1, wherein the at least one lock actuator comprises a pneumatic actuator. c4:[] The bonnet lock mechanism of claim 1, wherein the at least one lock actuator comprises an electrically powered motor. t4:;!] The bonnet lock mechanism of claim 1, wherein the at least one lock acmator comprisies a manually operated actuator. The bonnet lock rnechanisin of claim l;fiirtlier comprising a manual locking nrtechanism. A blowout preventer compriising: a body; a bonnet cooperatively attached to the body proximate each of at least two oppositely disposed side openings formed in the body; and a radi£il locking mechanism cooperatively attached to each bonnet and adapted to secure each bonnet to the body proximate an inner perimeter of the at least two side openings. Tlie blowout preventer of claim 44, wherein the radial locking mechanism further comprises: a radial lock; and at least one lock actuator operatively coupled to the radial lock, wherein the at least one lock actuator is adapted to radially displace the radial lock so as to form a locking engagement between an external surface of the radial lock and an internal surface of the at least two side openings, Tlie blowout preventer of claim 44, wherein the radial locking mechanism fiirther comprises: a radial lock; a ]-adial lock displacement device; and at leasi: one lock actuator operatively coupled to the radial lock displacement device, wherein the at least one lock actuator is adapted to axially displace the radial lock displacement device so as to radially displace the radial lock and form a locking engagement between an external surface of the radial lock and an internal surface of the at least two side openings, A blowout preventer comprising; a body; a bonnet cooperatively atoched to the body proximate each of at least two oppositely disposed side openings formed in the body; u bonnet door coupled to the bonnet; a radial lock; a radial lock displacement device; at least one lock actuator operatively coupled to the radial lock displacement device and to a bonnet door, and £: bonnet seal adapted to form a sealing engagement between the bonnet and the at least two side openings, vvhercoiB the at least one lock actuator is adapted to axi'ally displace the radial lock displacement device, the radial lock displacement device adapted to radially disiplace the radial lock so as to form a locking engagement between the bonnet and the at least two side openings. [c481 A blov/oiuit preventer comprising; a body; a bon:iet cooperatively attached to the body proximate each of at least two oj^positely disposed side openings formed in the body; a radiEil lock disposed in the body; ar least one lock actuator operatively coupled to radial lock, and A a bonnet seal adapted to fomi a sealing engagement between the bonnet and the at least two side openings, v/herein i:he at least one lock actuator is adapted to radially displace the radial lock so as to form a locking engagement between the bonnet and the body proximate the at least two side openings. [c49] A method for securing a bonnet to a body of a blowout preventer, the method comprising: pcsitioning the bonnet proximate a side opening of a body of the blowout preventer, activating at least one lock actuator operatively coupled to a radial lock displacement device; Eccially displacing the radial lock displacement device; and radiall}^ displacing the radial lock with the radial lock displacement device so as to form a locking engagement bet^^veen the bonnet and the body of the blowout preventer. The method of claim 49, wherein the activating further comprises powering a hydraiLlfc cylinder coupled to the radial lock displacement device. Tie method of claim 49, wherein the activating further comprises activating a manual actuator coupled to the radial lock displacement device, Tlie method of claim 49, further comprising engaging a manual locking mechanism after forming the locking engagement. The miithod of claim 49, fortlier comprising: fomiing a sealing engagement between the bonnet and the body of the blowout preventer. A method for securing a bonnet to a body of a blowout preventer^ the method conipnsing: pcsitiomng the bonnet proximate a side openi]ig of a body of the blowout ■preventer; activating at least one lock actuator operatively coupled to a radial lock, the radial lock disposed in the body of the blowout preventer; and radiall)' disq^lacing the radial lock so as to form a locking engagement between the bonnet and the body of the blowout preventer. The method of claim 54, further comprising: foiTning a sealing engagement, between the bonnet and the body of the blowout preventer. The method of claim 54, wherein the activatijig further compnses powenng a hydraulic cylinder coupled to the radial lock. A bonnet lock mechanism for a blowout preventer substantially as herein described with reference to the accompanying drawings.

Full Text

QUICK RELEASE BLOWOUT PREVENTER BONNET
Background of Invention
Field of the Invention
Ths invention relates generally to blowout preventers used in the oil and gas industry. Specifically, the invention relates to a blowout preventer with a nc»vel bonnet securing mechanism.
Background Art
Wd[\ control is an important aspect of oil and gas exploration. When drJIing; a well in, for example, oil and gas exploration applications, devices must b£: put in place lo prevent injury to personnel and equipment associated with the drilling activities. One such well control device is known as a blowout preventer (BOP).
Blowout preventers are generally used to seal a wellbore. For example, drilling wells in oil or gas exploration involves penetrating a variety of subsurface geologic structures, or "layers/^ Each layer generally comprises a spe;cific geologic composition such as , for example, shale, sagdstone,, limestone^ etc. Each layer may contain trapped fluids or gas at different fornation pressures, and the formation pressures increase with increasing depth. Tlie pressure in tl}e wellbore is generally adjusted to at least balance the fonnatioTii pressure by, for example, increasing a density of drilling mud in the wellbore or increasing pump pressure at the surface of the wdU
There are occasions during drilling operations when a wellbore may penstrate a layer having a formation pressure substantially higher that the pressure maintained in the wellbore. ^Vhen this occurs, the well is said to have *'taken a kick." The pressure increase associated with the kick is generally produced by an influx of formation fluids (which may be a liquid, a gas, or a

^.Dnibination thereof) into the wellbore. The relatively high pressure kick tends [0 propagate from a point of entry in the wellbore uphole (from a high pressure region to a low pressure region). If the kick is allowed to reach the surface, drilling fl uid, well tools, and other drilling structures may be blown out of the wellbore.. These ^'blowouts" often result in catastrophic destruction of the drilling equipment (including, for example, the drilling rig) and in substantial itijury or death of rig personneL
Eiecause of the risk of blowouts, blowout preventers are typically installed at tlie surface or on the sea floor in deep water drilling arrangements sc that lacks may be adequately controlled and 'circulated out" of the system. Blowout preventers may be activated to effectively seal in a wellbore until active rneasures can be taken to control the kick. There arc several types of blowouit preventers, the most common of which are annular blowout preventers and ram- type blowout preventers.
j .^nnulcir blowout preventers typically comprise annular elastomer
"packer:/' rJiat may be activated (e.g., inflated) to encapsulate drillpipe and well tools and completely seal the wellbore- A second type of the blowout preventer is the ram-type blowout preventer. Ram-type preventers typically comprise a body and lat least tvi^o oppositely disposed bonnets. The bonnets are generally secured to the body about their circumference with, for example, bolts. Allemaii'/ely, bonnets may be secured to the body with a hinge and bolts so that the bonnet may be rotated to the side for maintenance access. ^
I Interior of each bonnet is a piston actuated ram. The rams may be either
pips rams; (which, v/hen activated, move to engage and surround drillpipe and well tools to seal the wellbore) or shear rams (which, when activated, move to engage and physically shear any drillpipe or well tools in the wellbore). The rarns are typically located opposite of each other and, whether pipe rams or sheiir rams, the rams typically seal against one another proximate a center of the wellbore in order to completely seal the wellbore.

M with any tool used in drilling oil and gas wells, blowout preventers must be regularly maintained- For example, blowout preventers comprise high piessure seals between the bonnets and the body of the BOP. The high pressure seals in many instances are elastomer seals. The elastomer seals must be regularly checked to ensure that the elastomer has not been cut, peraianently deformed, or deteriorated by, for example, chemical reaction with the drilling fluid ill the wellbore. Moreover, it is often desirable to replace pipe rams with shear rams, or vice versa^ to provide different well control options. Therefore, it is important that the blowout preventer includes bonnets that are easily reraovaible so that interior components, such as the rams, may be accessed and maintained
][)eveloping blowout preventers that are easy to maintain is a difficult task- For example, as previously mentioned, bonnets are typically connected to the BOP body by bolts or a combination of a hinge and bolts. The bolts must be highly torqued in order to maintain a seal between a bonnet door and the BCiP body. The seal between the bonnet and the BOP body is generally a face seal, and the seal must be able to withstand the very high pressures present in the wellbore.
I As a result, special tools and equipment are necessary to install and
remove ihe bonnet doors and bonnets so that the interior of the BOP body may be acce£;sed. The time required to install and remove, the bolts connecting the bornet doors to the BOP body results in rig downtime, which is both expensive and inefficknt. Moreover, substantially large bolts and a nearly complete **bolt circle" sround the circumference of the bonnet door are generally required to provide jiufficient force to hold the bonnet door against the body of the BOP, The size of the bolts and the bolt circle may increase a "stack height" of the BO?. It is common practice to operate a "stack" of BOPs (where several BOPs are inst
Several attempts have been made to reduce stack height and the time required to access the interior of tlie BOP. U.S. Patent No- 5,655,745 issued to Morrill shows a pressure energized seal carrier that eliminates the face seal between the bonnet door and the BOP body. The BOP shov/n in the "745 patent enables the use of fev/er, smaller bolts in less than a complete bolt circle for securing the bonnet to the body. Moreovex, the *745 patent shows that a hinge may be used in place of at least some of the bolts.
U.S. Patent No. 5,897,094 issued to Brugman et al discloses an irnproved BOP door connection that includes upper and lower connector bars for securing bonnets to the BOP, The improved BOP door connection of the 'C'94 patent does not use bolts to secure the bonnets to the BOP and discloses a d Summary of Invention
In one aspect^ the invention comprises a bonnet lock mechanism for a blowout preventer. The bo^imet lock mechanism comprises a radial lock, a radial lock displacement device, and at least one lock actuator operatively coupled to the radial lock displacement device. The radial lock displacement device is adapted to radially displace the radial lock to a form flocking engageniient between a bonnet and a body of the blowout preventer.
In another aspect, the invention comprises a bonnet lock mechanism for a tlowc»iit preventer comprising a bonnet door operatively attached to a swivel slide moimt The swivel slide mount is adapted to slide in relation to a body of the blov/ont preventer. At least one lock actuator is coupled to the bonnet door, and a radial lock displacement device is operatively coupled to the at least one lock actjator. The bonnet is adapted to be slidably positioned proximate a side opening of ^ihe body of the blowout preventer. Tlie at least one lock actuator is adapted to axially displace the radial lock displacement device so as to radially

d. splace aradial lock to fonti a locking engagement between the bonnet and the body cif the blowout preventer.
In another aspect, the invention comprises a bonnet lock mechanism for a blowout preventer comprising a radial lock disposed in a body of the blowout preventer. At least one lock actuator is operatively coupled to the radial lock. The at least one lock actuator is adapted to radially displace the radial lock so that an internal surface of the radial lock forms; a locking engagement with a bonnet,
In another aspect, the invention comprises .a blowout preventer comprising a body, and a bonnet cooperatively attached to the body proximate each of ar. least two oppositely disposed side openings formed in the body. A radial locking mechanism is cooperatively attached to each bonnet and is adapted to secure each bonnet to the body proximate an inner perimeter of the at least rwo side openings.
hi another aspect, the invention comprises a bonnet seal adapted to form a sealing engagement between a bonnet and a body of a blowout preventer.
In a:nother aspect, the invention comprises a method for securing a bonnet to a body of a blowout preventer. The method comprises positioning the bonnet proximate a side opening of a body of the blowout preventer, activating at.least one lock actuator operatively coupled to a radial lock disjDlacement device, axially displacing the radial lock displaceipent device, and: radially displacing the radial lock with the radial lock displacement device so as to foim a locking engagement between the bonnet and the body of the blowout preventer.
In another aspect, the invention comprises a method for securing a bonnet to a body of a blowout preventer. The method comprises positioning the bonnet proximate a side opening of a body of the blowout preventer, activating arleast one lock actuator operatively coupled to a radial lock, the radial lock disposed in the body of the blowout preventer, and radially

iisplaciiig the radial lock so as to form a -locking engagement between the bonnet and the body of the blowout preventer
Other aspects and advantages of the invention will be apparent from the following description and the appended claims.
Brief Description of Drawings
Figure 1 f;hows a partial section and exploded view of a BOP comprising an embodiment of the invention.
FiE^ure 2 shows an enlarged view of a portion of the embodiment shown ir Figure L
Figure 3 shows an embodiment of a radial lock displacement device.
Fi^re 4 shows another embodiment of a radial lock displacement device.
Figure 5 shows an embodiment of the invention where a radial lock is pinned to a portion of a bonnet.
Figure 6 shows an embodiment of a radial lock comprising two halves.
Figure 7 shows an embodiment of a radial lock comprising four segments-
Figiure 8 shows an embodiment of a radial lock comprising a plurality of
se,?merit!5. . ►
]Figure 9 shows an embodiment of a notched serpentine radial lock,
]"igure 10 shows an embodiment of a locking mechanism used in an embodiment of the invention.
Ingure 11 shows an embodiment of a locking mechanism used in an embodiment of the invention.
Figure 12 shows an embodiment of a locking mechanism used in an embodiment of the invention.

Figure 13 shows an embodiment of a high pressure seal used in atp
n-ibodiment of the^ invention-Figure 14 shows an embodiment of a high pressure seal used in an
:;mbodin:ient of the invention.
FigTire 15 shows an embodiment of a high pressure seal used in an ^inbod'iment of the invention.
Figure 16 shows an embodiment of a high pressure seal used in an embodiment of the invention.
Figure 17 shows an embodiment of a high pressure seal used in an embodiment of the invention.
Figure 18 shows an embodiment of the invention wherein a radial lock is disposed in a recess in a side passage of a BOP body.
Figure 19 shows an embodiment of a radial lock comprising two halves.
J'igure 20 shows an embodiment of a radial lock comprising four
scj^ient::;.
Figure 21 shows an embodiment of a radial lock comprising a plurality of kerfs.
Figure 22 shows an erabodiment of a radial lock comprising graduated kenfs.
f'igure 23 shows a. side perspective view of an embodiment of a swivel slide mount used in an embodiment of the invention.
Figure 24 shows a front perspective view of an embodiment of a swivel slide mount used in an embodiment of the invention.
Figure 25 shows a top perspective view of an embodiment of a swivel slicie mc'unt used in an embodiment of the invention.

Detailed Descriptio0
An embodiment of the invention is shown in Figure 1. A ram-type blowout preventer (BOP) 10 comprises a BOP body 12 axjd oppositely disposed bonnet assemblies 14. The BOP body 12 further comprises couplings 16 (v/hich may be, for example, flanges) on an upper surface and a lower surfa(iB of the BOP body 12 for coupling the BOP 10 to, for example, another BOP or to another well tooL The BOP body 12 comprises an internal bore 18 therethrough for the passage of drilling fluids, drillpipe, well tools, and the like Lsed to drill, for example, an oil or gas well. The BOP body 12 further comprises a plurality of side passages 20 wherein each of the plurality of side passages 20 is generally adapted to be coupled to a bonnet assembly 14.
The bonnet assemblies 14 are coupled to the BOP body 12, typically in opposing pairs as shown in Figure 1. Each bonnet assembly 14 further comprises a plurality of components adapted to seal the bonnet assembly 14 to the BOP body 12 and to activate a ram piston 22 within each bonnet assembly 14. Components of the bonnet assembUes 14 comprise passages therethrough for movement of the ram piston 22.
Each bonnet assembly 14 generally comprises similar components.
^ ' s *
V/hile each bonnet assembly 14 is a separate and distinct part of the BOP 10,
the operation and structure of each bonnet assembly 14 is similar.
Accordingly, in order to simpliiy the description of the operation of the BOP
113 an bonnet assembly 14 will be (^escribed in detail It should be understood that
each bo'nnet assembly 14 operates in a similar manner and that, for example,
opposing bonnet assemblies 14 typically operate in a coordinated manner.
Proceeding with the description of the operation of one bonnet assembly 1A[, the piston 22 is adapted to be coupled to a ram (not shown) that may be, for e:x.ampie, a pipe ram or a shear ram. Each ram piston 22 is coupled to a ram actuatc-r cylinder 24 that is adapted to displace the ram piston 22 axially within

the bo:met assembly 14 in a direction genenilly peipendicular to an axis of the BOP body 12, the axis of the BOP body 12 being generally defined as a vertical a>:is of tlie internal bore 18 (which is generally parallel with respect to a wellbore axis), A ram (not shown) is generally coupled to the ram piston 22, and, if the rams (not shown) are shear rams, the? axial displacement of the ram piston 22 generally moves the ram (not sho^vn) into the internal bore J8 and into contact with a corresponding ram (not shown) coupled to a ram piston 22 in a bonnet assembly 14 disposed on an opposite side of the BOP 10.
Alternatively, if the rams (not shown) are pipe rams, axial displacement of the lam piston generally moves the ram (not shown) into the internal bore 18 and ini:o contact v/ith a coitesponding ram (not shown) and with drillpipe and/or wdl tools present in the wellbore. Therefore, activation of the ram actuator cylinder 24 displaces the ram piston 22 and moves the ram (not shown) into a position to. block a flow of drilling and/or formation fluid thi'ough the internal bore 18 of the BOP body 12 and, in doing so, to form a high pressure seal that prevents fluid flow from passing into or out of the we^llboie (not shown),
71ie ram actuator cylinder 24 further comprises an actuator 26 which
s tmy be, f:)r example, a hydraulic actuator, Hov/ever^ other types of actuators
are known in the art and may be used with the invention. Note that for purposes
of the description of the invention, a "fluid" may be defined as a gas, a liquid,
or i combination thereof
For example, if the ram {not shown) is a pipe ram, activation of the ram piston 22 moves the ram (not shown) into position to seal around drillpipe (not shcwTi) or well tools (not shown) passing through the internal bore 18 in the BOP body 12. Further, if the ram (not shown) is a shear ram, activation of the ram piston 22 moves the ram (not shown) into position to shear any drillpipe (not shoWTi) or well tools (not shown) passing through the internal bore-18 of the BOP body 12 and, therefore, seal the internal bore 18.

.Radial Lock Mechanism for Comlin^ Bonnets to BOPs
ATiimportant aspect of a BOP 10 is the mechanism by which the bonnet assemblies 14 are sealed to the body 12, Figure 1 shows a radial lock niech£;nism 28 that is designed to provide a high pressure radial seal between the bonnet assembly 14 and the BOP body 12. Moreover, the radial lock niechani::;m 28 is designed to simplify maintenance of the bonnet assembly 14 and the rams (not shown) positioned therein.
; In the embodiments shown in the Figures, the side passages 20 and other
components of the BOP 10 designed to be engaged therewith and therein are shown as being oval or substantially elliptical in shape. An oval or substantially elliptical shape {e.g., an oval cross-section) helps reduce the stack hdght of the BOP, thereby minimizing weighty material used, and cost. Other shapes such as circular shapes, however, are also suitable for use with the invention- Accordingly, the scope of the invention should not be limited to the shapes of the embodiments shown in the Figures,
The radial lock mechanism 28 is positioned within the bonnet assembly i4 and within the side passage 20 of the BOP body 12. In this embodiment, the
radial lock mechanism 28 comprises a bonnet seal 29 disposed on a bonnet
s
body 30,, a radial lock 32, a radial lock displacement device 34, a bonnet door 36, and lock actuators 38. The bonnet seal 29 cooperatively seals the bonnet body 30' to the BOP body 12 proximate the side passage 20. The bonnet seal 29 compnses a high pressure sea] that prevents fluids from the internal bore 18 of the BOP body 12 fromi»escaping via the side passage 20. Various embodiments of the bonnet seal 29 will be discussed in detail below.
When the bonnet seal 29 is fomied between the bonnet body 30 and the BC»P body 12, the bonnet body 30 is in an installed position and is located proxim^ite the BOP body 12 and at least partially within the side passage 20, Bec^ause: the bonnet seal 29 is a high pressure seal, the radial lock mechanism

23 inii:r>t be robust and able to withstand Very high pressures present in the interna] bore 18.
Tlie embodiment shown in Figure 1 comprises a novel mechanism for Icckingthe^bonnet assembly 14 (and, as a result, the bonnet seal 29) in place, ReferriBg to Figure 2, the radial lock 32 has an inner diameter adapted to fit over an exterior surface 40 of the bonnet body 30 and slide into a position adjacent a sealing end 45 of the bonnet body 30- The radial lock 32 shown in Figure 2 comprises two halves separated by a center cut 46. However, the radial iDck 32 niay comprise additional segments and the two segment embodiment shown in Figure 2 is not intended to ■ limit the scope of the invention.. Additional embodiments of the radial lock 32 will be described in greater detail below.
The radial lock displacement device 34 also has an inner diameter adapted to fit over the exterior surface 40 of the bonnet body 30, Moreover, tl-ie radiial lock'displacement device 34 fiirther comprises a wedge surface 48 on an external diameter that is adapted to fit inside an inner diameter 50 of the radial Ictck 32, The.radial lock displacement device 34 also comprises an inner fac:e 56 that is adapted to contact an outer surface 54 of the BOP body 12. In an insts.lled position, the bonr^et body 30, the radial lock 32, and the r^ial lock displacement device 34 are positioned between the BOP body 12 and the bonnet door 36. An inner surface 52 of tl-ie boimet door 36 is adapted to contact the outer surfade 54 of the BOP body 12. Note that the*'engagement between the bonnet door 36 and the BOP body 12 is not fixed (e.g., the bonnet door 36 is not bolted to the BOP body 12).
The boimet .assembly 14 is adapted to slidably engage at least one rod 70 through a swivel slide mouni; 74 (note that two rods 70 are shown slidably engaged,, through the swivel slide mounts 74, with each bonnet assembly 14 in Figure 1). As a result of the slidable engagement, the bonnet assembly 14 may slide along the rods 70. As will be discussed below, the slidable engagement

.penn:its the bonnet assembly 14 to be move^d into and out of locking and sealiiig engagement with the BOP body 12.
The lock actuators 38 are coupled to the bonnet door 36 with either a fixed or removable coupling comprising bolts, adhesive, welds, tlireaded connections, or similar means known in the art. The lock actuators 38 are also cooperatively coupled to the radial lock displacement device 34 in a similar fashion. Additionally, the coupling between the lock actuators 38 and the radial lock displacement device 34 may be a simple contact engagement. Note tliat tlie embodiments in Figure 1 shows two lock actuators 38 coupled to each bonnet door 36. However, a single lock actuator cylinder 38 or a plurality of lock actuators 38 may be used with the invention. The lock actuators 38 shown are generally hydraulic cylinders; however, other types of lock actuators (includmg, for example, pneumatic actuators, electrically powered motors^, and tlie like) Eire known in the an: and may be used with the invention.
Mloreover, the lock actuators 38 may also be manually operated. The lock aciluators 38 shown in the present embodiment are typically controlled by, for example, an external electrical signal, a flow of pressurized hydraulic fluid, etc. AiS an alternative, the radial lock 32 may be activated by manual means, such a;3, for example, a lever, a system of levers, a threaded actuation^device, lor oiher similar means known, in the art. Further, if, for example, the lock actuators 38 comprise hydraulic cylinders, the hydraulic cylinders may be activated by a manual pump- Accordingly, manual activation of the radial lock 32 is \\'ithin the scope of the invention.
A jully assembled view 15 of the bonnet assembly 14 including the i*idial lock mechamsm 28 is shown in Figure 2. During operation of the radial lock nriechanism 28, the bonnet assembly 14 is first moved into position proximate the BOP body 12 by sliding the bonnet assembly 14 toward the BOP body 1:2; on the rods 70- The lock actuators 38 are then activated so that they ajcially displace (wherein an axis of displacement corresponds to an axis of the

side passage 20) the radial lock displacement device 34 in a direction toward the BOP body 12. As the radial lock displacement device 34 moves axially toward the BOP body 12, the wedge surface 48 contacts the inner diameter 50 oJ'the radial lock 32, thereby moving the radial lock 32 in a radially outward directi \A^iien the radial lock 32 is secured in place by the activation of the lock acTuators; 38. and the.radial lock displacement device 34, the bonnet body 30 and the bonnet assembly )4.a:re axially .locked in place with respect toihe BOP body 12 without the use of, for example, bolts. However, an additional manual locking mechanism (not shown) may also be used in combination with the inventicm. to ensure that'the radial lock 32 remains securely in place. Once the radial lock 32 is secured in place by, for example, hydraulic actuation, a manual lock (not shown), such as a pinned or threaded mechanism, may be activatecl as an additional restraint. The secured radial locking mechanism 28 is designed to hold the bonnet assembly 14 and, accordingly, the high pressure bonnet seal 29 in place. The radial lock 32 and the high pressure bonnet seal 29 can vwithstand the high forces generated by the high pressures present within the internal bore 18 of the BOP body 12 because of the locking engagement

)etwKeii the radial lock 32 and the inner radial lock surface 58 of the BOP body 12-
The radial lock mechanism 28 may be disengaged by reversing the •.ctivatioB of the lock actuators 38 (e.g., after the pressure in the internal bore 18 has bec: relieved)- As a result^ the invention comprises a radial lock r.Liechanism 28 that includes a positive disengagement system (e.g., the lock actuators 38 must be activated in order to disengage the radial lock mechanism 28).
The wedge surface 48 used to radially displace.the radial lock 32 may comprise any one of several odiments. Referring to Figure 3, in one embodjrnentj the wedge surfa.. ^5 of the radial lock displacement device 34 may comprise a single actuation step 80, In another embodiment shown in Figure 4, the wedge surface 48 may comprise a dual actuation step 82. Note that the single actaation step (80 in Figure 3) generally has a shorter actuation snroke than the dual actuation step (82 in Figure 4). Further^ an actuation step angle (S4 in Figures 3 and 4) is designed to maximize a radial actuation force and minimize a linear actuation force. In one embodiment of the invention, the acjtuatio-n step angle (84 in Figures 3 and 4) is approximately 45 degrees. In aiiiothe:! embodiment of the invention, the actuation step angle (84 in^Figures'S and 4) is less than 45 degrees.
In another embodiment shown in Figuie 5, the radial lock displacement device 34 further comprises a slot 90 and at least one retention pin 92 designed to retain the radial lock 32 against the load shoulder 44 of the bonnet body 30. In this embodiment, the radial lock 32 is retained in place by the at least one retention pin 92, and the bonnet body 30 and the radial lock 32 are held in a filled relationship after the radial lock 32 has been actuated and is in locking engagement with die inner radial lock surface (58 in Figure 2) of the side passage (20 in Figure 1),

The radial lock (32 in Figure 1) may also comprise any one of several jmbodin-ients. The radial lock 32 shown in the embodiment of Figure 1 :ompnses tv/o radial mixrored halves 94, 96, ais further shown in Figure 6, In ■mother embodiment, as shown in Figure 7, a radial lock 100 may be formed from at least tv/o substantially linear segments 102 and at least two semicircular end segments 104, In another embodiment, as shown in Figure 8, a radial lock 106 may be formed from a pluraliiy Of substantially straight dogs I. [)8 and a plurality of curved dogs 110. The embodiments shown in Figures 7 and 8 essentially comprise radial locks 100,106 similar to the radial lock (32 in Figure^! 1 and 6) of the first embodiment but divided into a plurality of segments. The. radial locks 100^ 106 could be manufactured by, for example, rranufacturing a solid radial lock and sequentially saw cutting the solid radial Icck into two or more segments. However, other manufacturing techniques are kjiown in the art and may be used to manufacture the radial lock-In another embodiment shown in Figure 9,. a radial lock 112 may be formed fi:om a notched serpentine structure 114 similar to a "serpentine belt/* The racbal lock 112 is formed, for example, as a single solid piece and-then cut 117 through an inner perimeter 113 or an outer perimeter 116, The cuts 117 can either completely transect the radial lock 112 or may include only partial cuts. Further, if the cuts 117 transect the radial lock 112, the individual segmetits can be attached to a flexible band US so that the radial lock 112 can be actuated with an actuating ring (34 in Figiire 1). The flexible band 118 may comprise a material with a relatively low elastic modulus (when compared to, fo* example, the elastic modulus of the individual segments) so that the flexible band 118 can radially expand in response to the radial displacement produced by the radnal lock displacement device (34 in Figure 1). Radial expansion of th
The engagement between the radial lock (32 in Figure 1) and the inner radial lock surface (58 in Figure 2) may also comprise different embodiments. In ons embodiment, as shown in Figure 10, a radial lock 120 may comprise a single profile engagement including a single radial lock engagement surface 122. The single radial lock engagement surface 122 is designed to lockingly engage a BOP engagement surface (59 in Figure 2) formed on the inner radial lock surface (58 in Figure 2) of the side passage (20 in Figure 1).
In another embodiment, as shown in Figure 11, a radial lock 124 comprises a dual profile engagement including two radial lock engagement irarfaces 126. Moreover, the radial lock 124 may also comprise a plurality of radial lock engagement surfaces designed to lockingly engage a corresponding number of BOP engagement surfaces (59 in Figure 2) formed on the inner radial lock surface (58 in Figure 2) of the side passage (20 in Figure 1) of the BOP t>ody (12 in Figure 1).
I The radial locks described in the referenced embodiments are designed
so thsLt the cross-sectional area of engagement between the radial lock engagement surfaces with tlie BOP engagement surfaces (59 in Figure 2) is maximized- Maximizing the cross-sectional areas of engagement ensures that tihe radial locks positively lock the bonnet assembly (14 in Figure l)Aand, as>a result, the bonnet seal (29 in Figure 1) in place against the high pressures present in the internal bore (18 in Figure 1) of the BOP (10 in Figure I). Moreover, as discussed previously, angles of the engagement surfaces may be designed to produce an axial force that finnly pulls the bonnet door (36 in Fi]^re 1) against the BOP bo^dy (12 in Figure I) and that in some embodiments may assist in the activation of the bonnet seal (29 in Figure 1).
lilt:) radial locks and the engagement surfaces described in the foregoing embodiments may be coated with, for example, hardfacing materials and/or friction reducing materials. The coatings may help prevent, for example, galling, and may prevent the radial locks from sticking or "hanging-up" in the

engagement surfaces during the activation and/or deactivation of the radial lock n*iechanism (28 in Figure 1), The coatings may also increase- the life of the radial locks and the engagement surfaces by reducing friction and wean
Another embodiment of the lock ring 127 is shown at 127 in Figure 12. The radial lock 127 comprises a plurality of saw cuts 128, a plurality of holes 129, ox a combination thereof. The saw cuts 128 and/or holes 129 decrease the weight and area moment of inertia of the radial lock 127, thereby reducing the actuation force required to radially displace the radial lock 127. In-order to pr.rmit some elastic deformation of.the radia] lock 127, the radial lock 127 may bci fonned from a materia.1 having a relatively low modulus of elasticity (when cc»mpared to, for example, steel).. Such materials comprise titanium, beryllium copper, eic. Moreover, modifications to the radial lock 127 geometry, in addition to those referenced above,, may be made to, for example, further reduce the area.moment of inertia of the radial lock 127 and reduce bending stresses.
The: radial locks described above are designed to operate below an elastic limit of tlie materials, from which they are fonned. Operation below the elastic limit ensures that the radial locls will not permanently deform and, as a rcimlt of the permanent deformation, lose effectiveness. Accordingly^ material selecticm. and cross-sectional area of engagement of the engagement surfaces is very important to the design of the radial lock mechanism (28 in Figure 1).
Referring to Figure 1, the bonnet seal 29 is designed to withstand the high pressures present in the. internal bore IS of the BOP body 12 and to thereby prevent fluids and/or gases from passing from the internal bore 18 to the; exterior of the BOP 10. The bonnet seal 29 may comprise several different configurations as shown in the following discussion of Figures 13-17. Moreover, the seals disclosed in the discussion below may be formed from a vaiiety of materials. For example, the seals may be elastomer seals or non-elastomer seals (such as, for e;icample,.metal seals, PEEK seals, etc.). Metal

seals may further comprise metal-to-metaj C-ring seals and/or metal-to-metal lip seals- Further, the sealing arrangements shown below may include a combination of seal types and materials. Accordingly, the type of seal, number of seals, and the material used to form radial and face seals are not intended to limit the bonnet seal 29.
The embodiment in Figure 13 comprises a bonnet seal 130 formed on a radial perimeter 132 of a bonnet body 133, The radial seal 130 further c;omprises two o-rings 134 disposed in grooves 136 formed on the radial perimeter 132 of the bonnet body 133. The o-rings 134 sealingly engage an inner sealing perimeter 138 of the side passage (20 in Figure 1) in the BOP body 12. The embodiment shown in Figure 13 comprises two grooves 136, but a single j^roove or a plurality of grooves may be suitable for use with the o-rings 134, Moreover, while the embodiment shows two o-rings 134, a single o-ring or more than two o-rings may be used in the invention.
In another embodiment shown in Figure 14, a bonnet seal 140 comprises at lea£;i: tv/o packing seals 146 (which may be, for example^ t-seals, lip seals, or ssals Isold under the trademark PolyPak, which is a mark of Parker HannijQn, Ji]K.) In another embodiment shown in Figure 15, the bonnet seal 152 comprises a radial seal 154 disposed in a groove 166 formed on a radial perimeter 160 of a bonnet body 162. Moreover, the embodiment comprises a face seal 156 disposed in a giroove 164 formed on a mating face surface 168 of ths boime:it body 162, The radial sea] 154 is adapted to sealingly engage an

inner sealing perimeter 158 of the side passage (20 in Figure 1) of the BOP oody 12. The face seal 156 is adapted to sealir-gly engage an exterior face 170 of the BOP body 12. The radial seal 154 and face seal 156 shown in the embodiment are-both-o-rings and are disposed in single grooves 166, 164, However, a different type of seal (such as, for example, a packing seal) and more thain one seal (disposed in at least one groove) may be used with the invention.
In another embodiment shown in Figure 16, the bonnet seal 172
compiises a radial seal 174 disposed in a giroove 178 formed on a seal carrier
180. The seal carrier 180 is disposed in a gi'oove 182 formed in a bonnet body
1:54 and also comprises a face seal 176 disposed in a groove 177 foinied on the
seal carrier 180. The face seal 176 is adapted to sealingly engage mating face
surface 186 of the BOP body 12, and the radial seal 174 is adapted to sealingly
engage an inner sealing perimeter 188 fomied in the bonnet body 184. The
bonnei; seal 172 may also comprise an energizing mechanism 190 that is
adapted to displace.the seal carrier 180 in a direction toward the exterior
surface 186 of the BOP body 12 so as to energize the face seal 176. The
energizing mechanism 190 may comprise, for example, a spring, a thrust
washej; or a similar structure- s *
The energi2:ing mechanism 190 helps ensure that the face seal 176 maintains positive contact with and, thus, maintains a high pressure seal with the exterior surface 186 of the BOP body 12, However, the energizing mechanism 190 is not required in all embodiments. For example, the seal carrier 180 may be designed so that both the radial seal 174 and the face seal 176 are pressure activated v/ithout the assistance of an energizing mechanism 190.
In the embodiment without an energizing mechanism, a diameter and an a>cial thiicliiness of a seal carrier (such as the seal carrier 180 shown in Figure 16) are selected so that high pressure from the interna,] bore first moves the seal

oatrier toward the exterior surface of the BOP body. Once the face seal sealingVy engages the exterior surface, the high pressure from the intemal bore
causes the seal carrier to radially expand until the radial seal sealingly engages
■#-■
the groove in the seal carrier. A similar design is disclosed in U-S. Patent No. !5,255,890 issued to Morrill and assigned to the assignee of the present invention. The *890 patent clearly describes the geometry required for such a s;eal can'ier.
hi the embodiment shown in Figure 16, the face seal 176 and the radial seal 174 may be, for example^ o-rings, packing seals, or,any other high pressure seal known in the art. Moreover, Figure 16 only shows single seals disposed in single grooves. However, more than one seal, more than one groove, or a combination thereof may be used with the invention.
In another embodiment shown in Figure 17, the seal carrier 192 as shown in the previous embodiment is used in combination with a backup seal 194 disposed in a groove 196 on an external surface 198 of a bonnet body 200. Ihe backup seal 194 may be an o-ring, a pricking seal, a metal seal, or any other high pressure seal biown in the art. The backup seal 194 further iriaintainj; a liigh pressure seal if, for example, there is leakage from the seals disposeid on the seal carrier 192. Note that the embodiment shown in^igure 17 does not include an energizing mechanism.
Advaritageously, some of the seal embodiments reduce an axial force n In another embodiment of the radial lock shown in Figure 18, the radial lock mechanism 220 comprises a radial lock 222 disposed in a recess 224 fonned on an intemal surface 226 of a side passage 228 of a BOP body 230,

Tlie operation of the radial lock mechanism 220 differs from the embodiments described above in that securing a bonnet body 232 and/accordingly, a bonnet door (not shown) and a bonnet assembly (not shown), in place iis accomplished by actuating the radial lock mechanism 220 in radially inward direction-
The structure of the embodiment shown in Figure 18 is similar to the strucUEie of the embodiments described above except for the direction of actuation of the radial lock mechanism 220. Therefore, the discussion of the present embodiment will include a description of how the alternative radial lock mechanism 220 differs from those shown above. Common elements of the embodiments (such as, for example, the bonnet door 36, the linear rods 70, etc.) will not be described again in detail. Moreover, it should be noted that the embodiment of Figure 18 does not require, for example, actuator cylinders or a radial lock displacement device (e.g., the embodiment of Figure 18 does not require an internal actuation mechanism).
I Actuation of the radial lock 222 is in a radially inward direction.
Accordingly, the radial lock 222 must be coupled to an actuation mechanism tliat differs from, for example, the radial lock displacement device (34 in Figure ]) and the lock actuators (38 in Figure 1) described in the previous er-tbodiments- In one embodiment of the invention, the radial lock 222 ccmprises a structure similar to those shown in Figures 6 and 7. As shown in Figure 19, separate halves 236, 238 of the radial lock 222 may be cougled to radially positioned actuators 240. When the bonnet body 232 is moved jnto a sealing engagement with the BOP body 230, the actuators 240 are activated to diisplace the halves 236, 238 of the radial lock 222 in a radially inward dii-ectioTi, jio that the radial lock 222 engages a groove (244 in Figure 18) foimed on an exterior surface {246 in Figure 18) of the bonnet body (232 in Figure 18). The radial lock mechanism (220 in Figure IS) locks the bonnet body (^132 in Figure 18) and, therefore, the bonnfet door (not shown) and the bonnet assembly (not shown) in place and energizes the high pressure seal (234

n Figure 18). Note that the high pressure seal (234 in Figure 18) may be rormed from any of the embodiments shown above (such as the embodiments lesciibed with respect to Figures 13-17). Moreover, the radial lock 222 and ;he groove 244 may comprise angled suri^ces (as disclosed in previous embodiments) that produce an axial force that pulls the bonnet body 232 (and [he bonnet assembly (not shown) and bonnet door (not shown)) toward the BOP body 230 and forther ensure a positive loddng engagement.
Moreover, as shown in Figure 20, the radial lock 222 may comprise more than two parts. If a radial lock 250 comprises, for example, four parts ^152, 254, 256, 258, an equal number of actuators 240 (e.g., four) may be used to acmate the radial lock 250. Alternatively, fewer actuators 240 (e.g., less than four in the embodiment shown in Figure 20) may be used if an actuator. 240 is;, for example, coupled to more than one part parts 252, 254, 256, 258 of tie radiial lock 250, The acituators 240 may be hydraulic actuators or any other t/pe :tf actuator known in the art. Moreover, the actuators 240 may be disp05;c.d within the BOP body (230 in Figure 18) or may be positioned external to the BOP body (230 in Figure 18). The actuators 240 may be coupled to the radial Jock 250 with, for example, mechanical or hydraulic linkages (not sliowr). On another embodiment^ the radial lock 222 comprises a j^urality of dies or dogs (not shown) tliat are coupled to and activated by a plurality of actuators (not shown).
In another embbdiment of the invention shown in Figure ^1, a radial Icck 270 may be formed from a single segment 272. The radial lock 270 is actuated by circumferential actuators 274 coupled to the radial lock 270 and disposiid proximate ends 276, 278 of the segment 272. When activated, the circumferential actuators 274 move the ends 276, 278 of the segment 272 towards; each other and in a radially inward direction as shown by the arrows in Figure 21. The dashed line in Figure 21 represents an inner surface 277 6f the raiiial lock 270 after actuation. The radial lock 270, when actuated, engages

tlic bonnet body (232 in Figure 18) in a manner simikr to tliat shown in Figure
18-
^riie segment 272 of rJie radial lock 270 may be produced by forming a plurality of kerfs 284 proximate the end segments 280,282, The kerfs 284 may be desrigned to ease installation of the radial lock 270 in the recess (224 in Figure 18) and to improve flexibility for radial deformation of the radial lock 270, The kerfs may be of any shape kjiown in Ihe art: For example, Figure 22 shows rectangular kerfs 284. However, the kerfs 284 may preferably be formed in a manner that reduces stress concentrations, or stress risers at the edges of the kerfs 284. For example, if the kerfs 284 are formed as rectangular stiapes, stress risers may fonn at the relatively sharp comers. Accordingly, the ktirfs 284 may comprise filleted comers (not shown) or, for example, substantially trapezoidal shapes (not shown) to minimize the effects of stress nsers.
Moreover, the kerfs 284 may be "graduated,*' as shown in Figure 22, to produce ti substantially smooth transition be'tv^^een relatively stiff straight segments 286 and relatively flexible end segments 280, 282. Graduation of the ksrfs 284 effects a smooth stiffiiess transition that helps prevent stress risers at th(5 last kerf (e.^^, at the last kerf proximate the straight segments 286).^
rhe radial lock 270 may be formed from a single material or from
different materials (comprising, for example, steel, titanium, beryllium copper,
* *
or combinations and/or alloys thereof). For e^xample, the curved end segments
280, 282 may be fomied froi?i a material that is relatively compliant when
compared to a relatively rigid material fomiing the straight segments 286 (e.g.,
thei curved and segments 280,. 282 may be formed from a material with an
elastic modulus (Ec) that is substantially lower than.an.elastic modulus (Es) of
the^ straight segments 286). R.egardless of the materials used to form the radial
lock 27D, the radial lock 270 must be flexible enough to permit installation into
and removal from the recess (224 in Figure 18).

Altemativdyj the radial lock 270 of Fi;?ure 21 may comprise more than one sej?rnent (e.g., two halves or a plurality of segments) coupled to and actuated by a phrality of circumferential actuators- The radial lock 270 may also comprise a plurality of separate dies or dogs coupled by a flexible band. The dies may be separated by gaps, snd the distance of separation may be r»elec ted to provide a desired flexibility for the radial lock 270,
The dies and the flexible banding may comprise different materials. For example, the dies may be formed from a substantially stiff material (e.g., a material with a relatively high modulus of elasticity) comprising, for example, steel or nickel based alloys. The flexible banding, in contrast, may be foraied from materials having a relatively lower modulus elasticity and comprising, for example, titanium alloys or pultmded flats or shapes comprising fiberglass, carbon fibers, or composite materials thereof. As described above, the radial locks of the embodiments own in Figures 19-22 may be coated with, for example, hardfacing nniate.:als (comprising^ for example, tungsten carbide, boron nitride, and similar materials knov^n in the art) or low-friction materials (comprising, for example, polytetrafluoroelhyle^ne and similar materials known in the siri;) to, for example, reduce friction and wear and improve the longevity of the parts. The material composition of the radial lock 270 is not intended to be limiting.
The embodiments shown in Figures 19-22 may be advantageous because of a r€Jduced bonnet assembly weight and accordingly, reduced overall weight of the BOP. Moreover, there is a potential to retrofit old BOPs to include the rfi.dial lock mechanism.
SM^IVCI Slide Mount for Bonnet Assemblies
Refening again to Figure 1, another important aspect of the invention is the swivel slide mounts 74 cooperatively attached to fhe rods 70 and to each of the bc^iiBct assemblies J4. As described previously herein, the bonnet assemblies 14 are coupled to the swivel slide mounts 74, and the swivel slide

fnounts 74.are slidably engaged with the rods 70. The swivel slide mounts 74 ' Eire a(3apted to allow.the bonnet assemblies 14 to rotate proximate their axial c^entedmes so that the rams (not shown) and the interior components of bodi the bonnet assemblies 14 and the BOP body 12 may be accessed for rAainlenancej to change the rams, etc.
AJI embodiment of the swivel slide tDOunt 74 is shown in Figures 23 and 24. The swivel slide mount 74 comprises a swivel slide mounting bar 76 and a swivel plate 78. The swivel slide mounting bar 76 is slidably attached to the rods 70. The slidable attachment between the swivel shde mounting bar 76 and tlie rods 70 may be made with, for example, linear bearings 87 that are coupled to the sw/ivel slide mounting bar 76. However^ other shdable attachments known m the ait may be used with the invention to form the sHdeable attachment. Moreover, bushings (not shown), or a combination of linear bearings 87 and bushings (not shown) may be used with the invention. The SA'ivel. plate 78 is rotationally attached to the sv/ivel slide mounting bar 76 and is cooperatively attached to an upper surface 75 of the bonnet assembly 14. The cooperative attachment of the swivel slide mount 74 to the bonnet a;;semb'Jy 14 is made substantially at an axial centerline of the bonnet assembly
'■*■ . * •
'llie rods 70 are designed to be of sufficient length to permit the bonnet assembly 14 to disengage from the BOP body 12 and slide away from the BOP body 12 luintil the ram *(not shown) is completely outside the side passage 20, ^^Lo^eovfir, a point of attachment 82 where the swivel slide mount 74 is cooperatively attached to the upper surface. 75 of the bonnet assembly 14 may be optimized so that the point of attachment 82 is substantially near a center of mass of the bonnet assembly 14. Positioning the point of attachment 82 substanticilly near the center of mass reduces tlie force required to rotate the bc>nnet assembly 14 and also reduces the bending stress experienced by tie svwel nlate 78.

The swivel plate 78 may further include a bearing 85. For example, the bearing 85 may be cooperatively attached to the swivel slide mounting bar 76 and adapted to witlistand both radial and thrust loads generated by the rotation of the bonnet assembly 14. The bearing 85 may comprise, for example, a combination radial bearing and thrust bearing (such as, for example, a tapered roller bearing). Alternatively, the bearing 85 may comprise, for example, a roller bearing to support radial loads and a thrust washer to support axial loads. tlowever, other types of bearing arrangements are known in the art and may be used with the swivel plate 78.
)) When the ram (not shown) is completely out of the side passage 20, the
bonnet assembly 14 can rotate about a rotational axis of the swivel plate 78 so that the ram (not shown) and the side passage 20 may be accessed for maintcjnance, inspection, and the like. In the embodiment shown in Figures 23 itnd 24, the lower bonnet assembly 14 is shown to be rotated approximately 90 degrees wth respect to the BOP body 12 while the upper bonnet assembly 14 remains: m locking engagement with the BOP body 12. A ram block attachj-nent point 80 is clearly visible.
I] Figoire 25 shows a top view of the BOP 10 when one of the bonnet
aEsembhes 14 has been disengaged from the BOP body 12 and rotated approximately 90 degrees. As shown, the ram block attachment point 80 is clearly visible and may be vertically accessed. Vertical access is a significant advantage because prio^ art bonnets that include hinges generally pivot about an edge of the bormet door. Therefore, if, for example, a lower BOP bonnet was unbolted and pivoted open, the ram could not be vertically accessed because the body of the upper BOP bonnet was in the way. Vertical access to the ram is important because it makes it much easier to maintain or replace rams, tlios reducing the time required to maintain the BOP and increasing the level of safety of tlie personnel performing the ifhaintenance. Further, vertical

access; enables, for example, maintenance of a lower BOP bonnet while an i3pper boimet is locked in position (see, for example.. Figures 23-25).
The bonnet assembly 14 may also be rotated approximately 90 degrees bi the other direction with respect to an axis of the side passage (20 in Figure 1), thereby permitting approximately 180 degrees of rotation. However, other embodiment may be designed that permit rotation of greater than or less than 180 dci^i^rees. The range of rotation of the swivel slide mount 74 is not intended to Hm:t the scope of the invention.
The swivel slide mount 74 advantageous because-of the simplicity of the design and attachment to the bonnet assembly 14. For example, prior art h: nges are generally complex, difficult to manufacture, and relatively expensive. Further, prior art hinges have to be robust because they carry the full w«!:ight of the BOP bonnet about a vertical axis positioned some distance aAvay from the center of ma;£:s of the bonnet. The bending moment exerted on the hinge is, as a result, veiy high and dcfonriation of the hinge can lead to "s aggi]i g" of the bonnet.
While the invention has been described with respect to a limited number of embodiments, those skilled in the art, having benefit of this disclosure, will appreciate that other embodiments can be devised which do not depart from the scope of the invention as disclosed herein. Accordingly, the scope of the invention should be limited only by the attached claims.

What is claimed is:
Jcl] • A boiinef lock mechanism for a blowout preventer cornprising:
a ladial lock;
a radial lock displacement device; and
at least one lock actuator operatively coupled to the radial lock displacement
device, v^hereiii the radial lock disp>lacement device is adapted to radially displace the
radial lock to fonn a locking engagement between a bonnet and a body
of the blowout preventer.
[cl] I'he t'onnet lock mechanism of claim 1, wherein an external surface of the radial look is adapted to fonn a locking engagement with an intemal surface of a side opening of the body of the blowout preventer.
[c:51 The bcamet lock mechanism of claim 1, wherein the radial lock comprises two radially mirrored halves.
[C'll The bonnet lock mechanism of claim 1, wherein the radial lock comprises a p'uralily of radial lock segments,
}c5] The boi]inet lock mechanism of claim 4, wherein the plurality of r^ial lock sc:gmeniLS are cooperatively attached to a flexible band.
'-:tij T.ie bonnet lock mechanism of claim 5, wherenn the flexible band is formed from £1 material having a lower modulus of elasticity than a material from v/hich tlie plurality of radial lock segments are formed.
tl] The bonnet lock mechanism of claim 2, wherein the external surface of the rajial Hock comprises at least one radial lock engagement surface adapted to form a locking engagement v/ith at least one radial engagement surface formed on the internal surfi^ce of the side opening.

The bonnet lock mechanisiB of claim 7, wherem the at least one radial lock engagement surface and the at least one radial engagement surface comprise fiagagement angles of approximately 45 degrees.
The bomet lock mechanism of claim 7, wherein a cross sectional area of the locking engagement is maximized-
The bonnet lock mechanism of claim 1, fiirther comprising a bonnet seal.
The bonnet lock mechanism of claim 10, wherein the bonnet seal further comprises at least one radial seal adapted to sealingly engage an inner radial sealinji surface of the side opening.
The bonnet lock mechanism of claim 10, wherein the bonnet seal comprises at least one face seal adapted to sealingly engage'an inner face sealing sxirface of the side opening.
Ttie bonnet lock mechanism of claim 10, wherein the bonnet seal fiirther
comprises:
a seal carrier ring disposed within a groove foraied on an interior end of the
bonnet body; at least one radial seal disposed in a groove foimed on a radi£il surfdfce of the
issal carrier ring and adapted to sealingly engage a radial sealing surface
of the groove on the bonnet body; and at leasi: one face seal disposed in a groove fonncd on an interior surface of the
si^:il.carrier ring and adapted to seahngly engage a face sealing surface
of the side opening.
The bonnet lock mechanism of claim 1, v^herein formation of tlie locking engagement moves a bonnet door into a contact engagement with the body.
The bc-nnet lock mechanism of claim 1, wherein the radial lock comprises a
hardfac:ing material

lt:16] rbe bonnet lock mechanism of claim 1, wherein the radial lock comprises a friction reducing material,
(cl71 The bonnet lock mechanism of claim 2, wherein the internal surface of the side opening comprises a hardfacing material
[t:l8) The Ixmnet lock mechanism of claim 2, wherein the internal surface of the side openiiiig comprises a friction reducing material.,
[cl9] The bonnet lock mechanism of claim 1, further comprising a bonnet door coupled to the bonnet, wherein the at least one lock actuator is cooperatively attached to the bonnet door.
[tlO] The bonnet lock mechanismi of claim 2, wherein the at least one lock actuator is £idaptE;d to axially displace the radial lock displacement device.
I<::21 a bonnet lock mechanism for blowout preventer comprising> £. bonnet door opexatively attached to a bonnet and to a swivel slide mount, the swivel slide mount adapted to slide in relation to a body of the blowout preventer;
at leaiit one lock actuator coupled to the bonnet door;
a radial lock displacement device operatively coupled to the at least one lotk actuator; and
a radial lock,
^^herein the bonnet is adapted to be slidably positioned proximate a side opening of the body of the blowout preventer, and the at least one lock actuator is adapted to axially displace the radial lock displacement dei^ce so as to radially displace ttie radial lock to form a locking engagement between the bonnet and the body of the blowout preventer.
fc22] The bonnet lock mechanism of claim 21 ,,wherein the bonnet is adapted to slide in relation to the body of the blowout preventer along a line parallel to an axis oftheiside opening.

ic2;31 llie bDKnet lock mechanism of claim 21, wherein the at least one lock actuator is coupled to an external surface of the bontjet door, the lock actuator being adapted to pass through an opening in the bonnet door and operatively engage the radial lock displacement device.
[c;;4] The bonnet lock mechanism of claim 21, farther comprising a bonnet seal.
[clS] The bonnet lock mechanism of claim 24, wherein the bonnet seal is adapted to scalingly engage an interior seahng surface of the side opening.
[tUy] The bonnet lock.mechanism of claim 21, wherein an external surface of the ntdial ]ock displacement device comprises a wedge surface including at least one actuation step,
|c;!7] The bonnet lock mechanism of claim 26, wh&rein the at least one actuation step comprises an actuation step angle of approximately 45 degrees.
[c:;i8J Tie bonnet lock mechanism of claim 26, wherein the at least one actuation step comprises an actuation step angle of less than 45 degrees.
|ic:.;9J Tlie bonnet lock mechanism of claim 21, wherein the radial lock is slidably attached to the radial lock displacement device.
lc:iOI A bonnet lock mechanism for a blowout preventer comprising: a ::adial lock disposed in a body of the blowout preventer; and at least one lock actuator operatively coupled to the radial lock, wliereir.1 the at least one lock actuator is adapted to radially displace the radial k)ck so that an internal surface of ttie radial lock forms a locking e-ngagement with a bonnet positioned in a side opening of the body of the blowout preventer.
:31| Thie bonnet lock mechanism of claim 30^.\vherem the radial lock comprises at least C'lie segment, the at least one segment comprising at least one substantially straight segment and at least two curved segments.

t32] The iD'Onnet lock mechanism of claim 31, v^erein the at least two curved segments comprises a plurality of kerfs.
t331 iTie bonnet lock mechanism of claim 32, wherein the kerfe comprise substantjially rectangular shapes.
c34] iTie bonnet lock mechanism of claim 32,, wherein the kerfs comprise siibst£Liitially trapezoidal shapes.
[c3f;] TTie bonnet lock mechanism of claim 31, wherein the at least one substantially s'Taiglit segment is formed from a different material than a material forming the at least two curved segments.
[c361 The bonnet lock mechanism of claim U wherein the at least one lock actuator is ci:>upled to the bonnet.
c::(7) The bonnet lock mechanism of claim 1, wherein the at least one lock actuator is coupled to a bonnet door that is coupled to the bonnet,
t:S] T^ie bc>nnet lock mechanism of claim 37, wherein the at least one lock actuator is; coufiled to an exterior surface of the bonnet door,
c39| Tlie bcmncrt lock mechanism of claim 1, wherein the at least^one lock actuator ccmpriseii: a hydraulic actuator.
!:40]| The bonnet lock mechanism of claim 1, wherein the at least one lock actuator comprises a pneumatic actuator.
c4:[] The bonnet lock mechanism of claim 1, wherein the at least one lock actuator comprises an electrically powered motor.
t4:;!] The bonnet lock mechanism of claim 1, wherein the at least one lock acmator comprisies a manually operated actuator.

The bonnet lock rnechanisin of claim l;fiirtlier comprising a manual locking nrtechanism.
A blowout preventer compriising:
a body;
a bonnet cooperatively attached to the body proximate each of at least two
oppositely disposed side openings formed in the body; and a radi£il locking mechanism cooperatively attached to each bonnet and adapted
to secure each bonnet to the body proximate an inner perimeter of the at
least two side openings.
Tlie blowout preventer of claim 44, wherein the radial locking mechanism
further comprises:
a radial lock; and
at least one lock actuator operatively coupled to the radial lock,
wherein the at least one lock actuator is adapted to radially displace the radial lock so as to form a locking engagement between an external surface of the radial lock and an internal surface of the at least two side openings,
Tlie blowout preventer of claim 44, wherein the radial locking mechanism
fiirther comprises:
a radial lock;
a ]-adial lock displacement device; and
at leasi: one lock actuator operatively coupled to the radial lock displacement device,
wherein the at least one lock actuator is adapted to axially displace the radial lock displacement device so as to radially displace the radial lock and form a locking engagement between an external surface of the radial lock and an internal surface of the at least two side openings,
A blowout preventer comprising; a body;

a bonnet cooperatively atoched to the body proximate each of at least two oppositely disposed side openings formed in the body;
u bonnet door coupled to the bonnet;
a radial lock;
a radial lock displacement device;
at least one lock actuator operatively coupled to the radial lock displacement device and to a bonnet door, and
£: bonnet seal adapted to form a sealing engagement between the bonnet and the at least two side openings,
vvhercoiB the at least one lock actuator is adapted to axi'ally displace the radial lock displacement device, the radial lock displacement device adapted to radially disiplace the radial lock so as to form a locking engagement between the bonnet and the at least two side openings.
[c481 A blov/oiuit preventer comprising; a body; a bon:iet cooperatively attached to the body proximate each of at least two
oj^positely disposed side openings formed in the body; a radiEil lock disposed in the body;
ar least one lock actuator operatively coupled to radial lock, and A a bonnet seal adapted to fomi a sealing engagement between the bonnet and the
at least two side openings, v/herein i:he at least one lock actuator is adapted to radially displace the radial
lock so as to form a locking engagement between the bonnet and the
body proximate the at least two side openings.
[c49] A method for securing a bonnet to a body of a blowout preventer, the method
comprising:
pcsitioning the bonnet proximate a side opening of a body of the blowout
preventer,

activating at least one lock actuator operatively coupled to a radial lock
displacement device; Eccially displacing the radial lock displacement device; and radiall}^ displacing the radial lock with the radial lock displacement device so
as to form a locking engagement bet^^veen the bonnet and the body of the
blowout preventer.
The method of claim 49, wherein the activating further comprises powering a hydraiLlfc cylinder coupled to the radial lock displacement device.
Tie method of claim 49, wherein the activating further comprises activating a manual actuator coupled to the radial lock displacement device,
Tlie method of claim 49, further comprising engaging a manual locking mechanism after forming the locking engagement.
The miithod of claim 49, fortlier comprising:
fomiing a sealing engagement between the bonnet and the body of the blowout preventer.
A method for securing a bonnet to a body of a blowout preventer^ the method
conipnsing:
pcsitiomng the bonnet proximate a side openi]ig of a body of the blowout
■preventer; activating at least one lock actuator operatively coupled to a radial lock, the
radial lock disposed in the body of the blowout preventer; and radiall)' disq^lacing the radial lock so as to form a locking engagement between
the bonnet and the body of the blowout preventer.
The method of claim 54, further comprising:
foiTning a sealing engagement, between the bonnet and the body of the blowout preventer.

The method of claim 54, wherein the activatijig further compnses powenng a hydraulic cylinder coupled to the radial lock.

A bonnet lock mechanism for a blowout preventer substantially as herein described with reference to the accompanying drawings.

Documents:

1735-chenp-2003-abstract.pdf

1735-chenp-2003-assignement.pdf

1735-chenp-2003-claims duplicate.pdf

1735-chenp-2003-claims original.pdf

1735-chenp-2003-correspondnece-others.pdf

1735-chenp-2003-correspondnece-po.pdf

1735-chenp-2003-description(complete) duplicate.pdf

1735-chenp-2003-description(complete) original.pdf

1735-chenp-2003-drawings.pdf

1735-chenp-2003-form 1.pdf

1735-chenp-2003-form 26.pdf

1735-chenp-2003-form 3.pdf

1735-chenp-2003-form 5.pdf

1735-chenp-2003-other documents.pdf

1735-chenp-2003-pct.pdf

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Patent Number

202802

Indian Patent Application Number

1735/CHENP/2003

PG Journal Number

05/2007

Publication Date

02-Feb-2007

Grant Date

06-Nov-2006

Date of Filing

03-Nov-2003

Name of Patentee

M/S. HYDRIL COMPANY

Applicant Address

3300 North Sam Houston Parkway East Houston, TX 77032

Inventors:

#	Inventor's Name	Inventor's Address
1	BERCKENHOFF, Michael, Wayne	30910 Coral Park Drive Spring, TX 77386
2	HEMPHILL, Edward, Ryan	10727 Oak Acres Drive Houston, TX 77065

PCT International Classification Number

E21B33/06

PCT International Application Number

PCT/US2002/014146

PCT International Filing date

2002-05-03

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	09/849,819	2001-05-04	U.S.A.