Abstract: A technique facilitates reliable operation of a blowout preventer (BOP) system. The reliable operation is achieved by utilizing a ram with improved strength so as to make it better able to resist the stresses from shearing without increasing the thickness of the ram blade. As a result, a high level of efficiency is maintained during a shearing action. According to an embodiment, a blowout preventer system comprises a blowout preventer shear ram assembly having a ram for shearing a tubular member. The ram comprises a main body and a blade extending from the main body. Additionally, a ramp buttress is secured to the blade to strengthen the blade and to improve the shearing action.

Abstract: A polished rod blowout preventer (BOP) ram seal is created by installing a rubber seal component onto a movable metal ram block that allows the ram to be opened and closed. The rubber seal is installed into a corresponding groove on the metal ram block or body that allows for compression of the seal between the polished rod, BOP ram housing, and ram bodies. The anti-extrusion features allow for use in high velocity and high-pressure applications. A blind seal embodiment is also disclosed.

Abstract: An equalization valve includes a valve body defining an inlet body, an outlet body, and a gate slot, the inlet body defining an inlet passage and the outlet body defining an outlet passage; a gate defining an equalization chamber, a first equalization channel, and a second equalization channel, the equalization chamber and the first and second equalization channels defining an equalization pathway across the gate; and an actuation stem slidable within the equalization chamber between a first chamber position, wherein the actuation stem blocks the equalization pathway, and a second chamber position, wherein the actuation stem unblocks the equalization pathway; wherein the actuation stem is further slidable within the gate slot of the valve body between a first valve position, wherein the gate is seated with the valve body, and a second valve position, wherein the gate is unseated from the valve body.

Abstract: An electric bonnet includes a housing; a guide piston disposed in the housing; an electric motor having a motor shaft; a rear housing connected to the housing; a gearbox assembly disposed in the rear housing, the gearbox assembly being coupled to the motor shaft of the electric motor; and a roller screw assembly disposed in the rear housing. A first end of the roller screw assembly is connected to the gearbox assembly, and a second end of the roller screw assembly is connected to the guide piston. Rotation of the motor shaft of the electric motor transmits rotary motion to the gearbox assembly, which transforms the rotary motion into linear motion using the roller screw assembly. The linear motion of the roller screw assembly actuates the guide piston.

Abstract: A drilling and production system is provided. In one embodiment, such a system has a plurality of functions that are effectuated at least predominately without hydraulic fluid. The system can be a drilling system having a rig and a subsea stack for performing various drilling functions, in which a majority of the drilling functions are effected electrically without hydraulic control fluid. In another embodiment, the rig is coupled to a subsea wellhead assembly but is not connected so as to provide hydraulic control fluid from the rig to the subsea wellhead assembly to enable drilling functions of the subsea wellhead assembly. Additional systems, devices, and methods are also disclosed.

Abstract: The present disclosure relates to a system that includes a ram configured to mount in a blowout preventer. The ram includes a packer assembly configured to form a seal between the ram and a bore formed through the blowout preventer and an insert of the packer assembly, where the insert is coupled to a surface of the ram via a key-slot interface.

Abstract: A drilling and production system is provided. In one embodiment, such a system has a plurality of functions that are effectuated at least predominately without hydraulic fluid. The system can be a drilling system having a rig (20) and a subsea stack (14) for performing various drilling functions, in which a majority of the drilling functions are effected electrically without hydraulic control fluid. In another embodiment, the rig is coupled to a subsea wellhead assembly (14) but is not connected so as to provide hydraulic control fluid from the rig to the subsea wellhead assembly to enable drilling functions of the subsea wellhead assembly. Additional systems, devices, and methods are also disclosed.

Abstract: In a blowout preventer central bore and a central bore axis with an oval ram cavity having a ram cavity axis having one or more horizontal interface portions between the ram cavity and an actuator body, a method of connecting the actuator body to the ram cavity comprising providing one or more locking bar receptacles passing through one or more of the planes of the one or more horizontal interface portions of the ram cavity, providing one or more locking bar receptacles passing through one or more of the planes of the one or more horizontal interface portions of the actuator body, and providing one or more locking bars in one or more of the one or more locking bar receptacles in both the ram cavity and the actuator body.

Abstract: An accumulator system that includes a housing. The housing defines a function chamber and a balance chamber. A piston moves axially within the housing. The piston separates the function chamber from the balance chamber. An electric actuator couples to and drives the piston within the housing to compress and drive a first fluid out of the function chamber.

Abstract: The present disclosure relates to a drive system for a blowout preventer (BOP). The drive system includes a first pseudo direct drive (PDD) motor assembly having a first PDD motor and a second PDD motor assembly having a second PDD motor. The first PDD motor is configured to engage with a first shaft coupled to a first ram of the BOP and the second PDD motor is configured to engage with a second shaft coupled to a second ram of the BOP. The first PDD motor and the second PDD motor are operable to induce translation of the first shaft and the second shaft, respectively, to drive the first ram and the second ram toward one another along a longitudinal axis to reach an engaged configuration in the BOP.

Abstract: A sealing apparatus includes a moveable seal holder with a cavity and includes a seal assembly disposed at least partially in the cavity. The seal assembly includes a resilient seal member including a fluid-facing end with a fluid-facing end surface, and the seal assembly includes an actuator plate configured to reciprocate between a first and a second position relative to the protective plate. The first actuator plate includes a fluid-facing end surface and a first camming surface. The seal assembly further includes a first protective plate disposed between the seal member and the first actuator plate. The actuator plate is configured to compress the seal member and to move the fluid-facing end surface of the seal member outward from a resting position when the actuator plate is in the second position.

Abstract: An improved ram assembly for a blowout preventer having a design that permits the seals of the ram assembly to be located in the working area and out of the way of threads or other rough/jagged surfaces that could damage the seals in the event of failure of the blowout preventer, such as if the threaded connection fails and the rams are suddenly pushed outwards. The ram assembly can also have a pin-and-groove mechanism that permits the rams to rotate when in the closed/sealing position to account for a misaligned rod. Further, the ram heads of the ram assembly can have a sufficient length such that they remain supported by the bonnet and ram bores of the blowout preventer against radial deflection, relative to the ram bore, when in the closed position and exposed to wellbore pressure. Additionally, the actuators of the ram assembly remain axially stationary during use.

Abstract: Offshore production systems and methods relating thereto are disclosed. In an embodiment, the offshore production system includes a surface vessel. In addition, the offshore production system includes a closed-loop cooling fluid circulation system extending subsea from the vessel and configured to cool a cooling fluid. The closed-loop cooling fluid circulation system includes a first tendon having an upper end coupled to the surface vessel and a lower end coupled to the seabed. The first tendon is in tension between the upper end and the lower end. The first tendon is configured to flow the cooling fluid from the lower end of the first tendon to the upper end of the first tendon.

Abstract: A blowout preventer (BOP) for controlling pressure within a wellbore includes a body having a front side and a back side, the front side being opposite the back side. The BOP also includes a door opening extending through the front side. The BOP further includes an operator opening extending through the body, perpendicular to the door opening. The BOP includes an outlet extending from an inner cavity of the body through the back side, the inner cavity being fluidly coupled to both the outlet and the door opening. The BOP also includes a ram passage forming at least a portion of the inner cavity, wherein the ram passage is arranged substantially perpendicular to the door opening.

Abstract: A double acting accumulator system includes a housing including an actuator housing, a first piston housing coupled to the actuator housing, a second piston housing coupled to the actuator housing, a shaft configured to move axially within the first piston housing and the second piston housing, a first piston coupled to a first end of the shaft, a second piston coupled to a second end of the shaft, an electric actuator configured to couple to and drive the shaft to alternatingly compress fluid with the first piston in the first piston housing and the second piston in the second piston housing to drive fluid out of the respective first piston housing and the second piston housing, and a plurality of anti-rotation shafts configured to block rotation of the shaft.

Abstract: A blowout preventer (BOP) for controlling pressure within a wellbore includes an internal cavity and a front side including a door opening, the door opening providing access to the internal cavity. The BOP also includes a door assembly associated with the door opening. The door assembly includes a door, movable between a first position and a second position, the door blocking access to the internal cavity in the first position and enabling access to the internal cavity in the second position. The door assembly also includes a hinge coupled to the door to facilitate movement of the door between the first position and the second position. The door assembly further includes a coupling device associated with the door, the coupling device securing the door to the front side. The BOP also includes a back side including an outlet, the outlet being fluidly coupled to the internal cavity.

Abstract: A throttling flow control valve that allows to adjust an amount of flow by adjusting a size of a flow path through the valve comprises a body having inlet and outlet branch pipes with through passages, and a control element having movable regulating teeth each having an individual actuator and fixed regulating teeth. The movable regulating teeth and fixed regulating teeth each have a streamlined shape ending with a symmetrical wedge. The control element provides a throttling zone having a cross section in a shape of a multi-point star. By action of individual actuators, movable regulating teeth move on fixed regulating teeth, which results in efficient flow control due to varying of the throttling zone area.

Abstract: A fluid management system for controlling fluid flow at a wellbore includes a closing element formed complementary to a drill pipe disposed within the wellbore and an activation system. The activation system is configured to move the closing element into an activated position against the drill pipe to close the wellbore around the drill pipe for preventing fluid from flowing out of the wellbore. The activation system includes an activation shaft coupled to the closing element and a rotatable drive shaft configured to cause translation of the activation shaft to push the closing element into the activated position against the drill pipe.

Abstract: An assembly for a blowout preventer includes a ram having a threaded opening. The assembly also includes a threaded shaft to engage the threaded opening and a motor to drive rotation of the threaded shaft. Rotation of the threaded shaft causes the ram to move axially along the threaded shaft.

Abstract: A blowout preventer (BOP) includes a main body that includes a bore extending through the main body. The BOP also includes a cavity intersecting the bore and a pair of opposing shear rams configured to shear a tubular located in the bore. The opposing shear rams are two duplicate shear rams.

Abstract: A low-volume non-rising stem gate valve comprising a hollow stem, planetary roller screw and anti-rotation rods. The anti-rotation rods isolate the torque force and maintain the alignment of the planetary roller screw with the stem and the screw shaft, thus reducing the amount of material necessary to support ordinary operational forces.

Abstract: A carburetor with a body with a cavity in which an adjustable fuel valve is received. To inhibit access to and manual adjustment of the valve, a cover may overlay at least a portion of the adjustable valve. In some forms, a releasable lock plate may be received between the cover and the adjustable valve. Specialty tools may release the lock plate and adjust the valve.

Abstract: A BOP booster assembly is provided for use with BOPs that utilize hydraulic actuators mounted in BOP end caps to open the BOP for replacement of the shearing members. The booster assembly has three main components comprising a booster housing, piston, and end plate. An extension in the booster housing is sufficiently long to position the booster hydraulic cylinder axially outside of the ends of the bonnet end caps of the BOP with respect to the wellbore. The booster piston is equal in diameter or larger than the operating piston of the BOP. The operating pistons and booster pistons move simultaneously, in sync, and the same distance for closing and cutting. In one embodiment, an internal hydraulic line is provided in the booster cylinder wall.

Abstract: In one aspect, valve seats are described herein having structure and design addressing degradative stresses encountered by the seats during installation and operation in fluid ends. In some embodiments, a valve seat for use in a fluid end comprises a first section for insertion into a fluid passageway of the fluid end and a second section extending longitudinally from the first section, the second section comprising a frusto-conical valve mating surface, wherein the second section is encased in a ring imparting a compressive stress condition to the second section.

Abstract: A blow out preventer bonnet removal method is provided for removing a bonnet from the body of a blow out preventer. The method includes attaching a rail system to the body that extends laterally away from the body. A carriage apparatus is mounted on the rail system. A saddle is connected to the bonnet. The bonnet is then detached from the body. The bonnet is then moved on the rail system from a first position next to the body to a second position spaced away from the body. The carriage apparatus transports the bonnet upon the rail system when moving from the first to the second position.

Abstract: In one aspect, valve seats are described herein having structure and design addressing degradative stresses encountered by the seats during installation and operation in fluid ends. In some embodiments, a valve seat for use in a fluid end comprises a first section for insertion into a fluid passageway of the fluid end and a second section extending longitudinally from the first section, the second section comprising a frusto-conical valve mating surface, wherein the second section is encased in a ring imparting a compressive stress condition to the second section.

Abstract: An apparatus includes a housing and at least two pipe ram systems engageable with the housing. Each of the at least two pipe ram systems comprises an actuator, a bonnet and a sealing pipe ram element. The at least two pipe ram systems are disposed on opposed sides of the housing. A carousel is disposed proximate at least one of the at least two pipe ram systems. The carousel has mounted thereon a plurality of pipe ram systems. The carousel is rotatable to orient a selected one of the plurality of pipe ram systems toward a receiving bore in the housing.

Abstract: A seal for a blind shear ram is configured to extend between a first carrier and a second carrier of the blind shear ram. The seal includes a curved portion and an elastic layer extending through the curved portion. The elastic layer is configured to contact at least one of the first carrier and the second carrier to seal a wellbore when the first carrier and the second carrier are in a closed position. The elastic layer has a first elasticity. The seal also includes an anti-extrusion structure coupled to the elastic layer. The anti-extrusion structure extends through the curved portion. The anti-extrusion structure has a second elasticity less than the first elasticity. The anti-extrusion structure defines a plurality of slits to facilitate the anti-extrusion structure extending through the curved portion.

Abstract: A Compact Bonnet Booster (CBB) housing is monolithically formed to include an operating piston chamber, a booster piston chamber and two BOP bonnet end caps. When the CBB is assembled, the two BOP bonnet end caps contain bonnet hydraulic assemblies utilized to open and close the CBB housing with respect to a central BOP housing interior to change out the shear members. The CBB housing also defines therein hydraulic lines to open and close the wellbore utilizing the shear members as well as to operate the bonnet hydraulic assemblies. The CBB housing also incorporates a lifting pad eye near a center of gravity of said BOP. The CBB assembly also comprises a monolithically formed operating piston and corresponding shaft as well as a monolithically formed booster piston and corresponding shaft.

Abstract: A wiper (200a) for a blowout preventer having an adapter ring (102a) and a piston (104a) slideable relative to the adapter ring along an interface can include a base (202) adapted to couple the wiper to the adapter ring and a head (204) coupled to the base. The head can include a first portion adapted to bridge the interface and contact the piston and a second portion adapted to contact the adapter ring and support the first portion. The second portion of the head can be adapted to at least partially resist rotation of the wiper. A blowout preventer can include one or more wipers as shown and described.

Abstract: The invention relates to a well bore control apparatus, system and method for sealing a well bore. The invention relates to a well bore control apparatus (20) comprising a housing (27) having a guide element (36) defining a path, the housing defining a throughbore (23) for receiving a tubular, a first tapered gate (64a) and a tapered second gate (64b) located within the housing, the first and second gates being adapted to engage with the guide element. In use the first and second gates are moveable along the path defined by the guide element in a direction substantially transverse to the throughbore between an open position of the throughbore and a closed position of the throughbore. The well bore control apparatus comprises a first seal seat (42) for forming a first seal with the first gate in the closed position to seal the throughbore. The well bore control apparatus may include a second seal seat (44).

Abstract: A Compact Bonnet Booster (CBB) housing is monolithically formed to include an operating piston chamber, a booster piston chamber and two BOP bonnet end caps. When the CBB is assembled, the two BOP bonnet end caps contain bonnet hydraulic assemblies utilized to open and close the CBB housing with respect to a central BOP housing interior to change out the shear members. The CBB housing also defines therein hydraulic lines to open and close the wellbore utilizing the shear members as well as to operate the bonnet hydraulic assemblies. The CBB housing also incorporates a lifting pad eye near a center of gravity of said BOP. The CBB assembly also comprises a monolithically formed operating piston and corresponding shaft as well as a monolithically formed booster piston and corresponding shaft.

Abstract: A polished rod BOP ram seal is formed with protrusions that are disposable in corresponding seal retention pockets formed in a seal-receiving groove in a BOP ram receiving the seal. The resultant mechanical interlock between the ram seal and the ram provides increased resistance to extrusion of the seal from the ram under high-pressure, high-velocity fluid flow conditions through the BOP.

Abstract: A blowout preventer (“BOP”) includes a housing comprising a vertical bore extending through the housing and a packer assembly movably positioned within the housing and configured to form a seal within the housing. The packer assembly includes an elastomeric body comprising an elastomeric material and inserts positioned within the elastomeric body and in parallel alignment with respect to each other.

Abstract: A bonnet assembly for assisting to move a valve stem to a retracted position includes a bonnet body. The bonnet body has a bonnet valve end selectively connected to a valve, a bonnet actuator end opposite the bonnet valve end selectively connected to a valve actuator. A valve stem extends through the central bore of the bonnet body. A booster piston seal circumscribes the valve stem and engages an inner diameter of the central bore. The booster piston seal selectively defines an extent of a pressure cavity containing pressure media. An effective stem pressure surface faces in a direction towards the valve and is in fluid communication with the valve when the bonnet body is connected to the valve. A booster pressure surface faces in a direction towards the valve when the bonnet body is connected to the valve and is selectively acted on by the pressure media.

Abstract: A wellhead apparatus with a removable sealing wafer is provided. In one embodiment, an apparatus includes a wellhead housing with a pocket formed in its upper end and a wafer installed in the pocket. A flange is coupled to the exterior of the upper end of the wellhead housing, and an additional component is coupled to the wellhead housing via the flange. Further, a first seal is positioned between the wafer and a shoulder of the wellhead housing, and a second seal is positioned between the wafer and the additional component. Additional systems, devices, and methods are also disclosed.

Abstract: Diverter assemblies having a housing, first and second rams, first and second actuators for moving the rams, and first and second sealing members respectively coupled to the first and second rams. The housing defines openings surrounding a drilling axis and configured to receive a pipe in a drilling position, and the rams are moveable relative to a longitudinal axis of the housing that is substantially perpendicular to the drilling axis. The first and second sealing members engage the pipe, and projections within the housing cooperate with the sealing members to form a seal around the pipe and the openings of the housing. Systems and methods of using the diverter assemblies are also disclosed.

Abstract: An improved multi-cavity blowout preventer is disclosed. The improved multi-cavity blowout preventer includes a first cavity and a first actuator assembly coupled to the first cavity. A second cavity is disposed adjacent to the first cavity and a second actuator assembly is coupled to the second cavity. The second cavity is disposed at an angular offset from the first cavity.

Abstract: A sealing system for a well valve includes a valve closure, a valve closure carrier, and seal elements. The valve closure includes a central bore. The valve closure carrier includes an annular, metal sealing surface in contact with the exterior of the valve closure to form a metal-to-metal seal with the valve closure. The valve closure carrier defines two flow holes, each of which communicates with the central bore when the valve closure is open to flow fluid, and is sealed from the central bore by the sealing surface when the valve closure is closed. The first seal element seals between the valve closure carrier and the valve closure, and surrounds the first flow hole. The second seal element seals between the valve closure carrier and the valve closure, and surrounds the first seal element and an end opening of the central bore when the valve closure is closed.

Abstract: A push member and a caulking gun having the same. The caulking gun includes the push member, a gun body and a push rod. The push member includes a blockable receiving portion which includes a receiving space and a lip protruding from a periphery of the receiving space, and a push portion arranged opposite to the blockable receiving portion in a first direction, for pushing a caulk cartridge. The lip defines a blocking mouth, and the blocking mouth and the receiving space are open toward a same lateral side of the push member to form an open end. When a push plate of the push rod is disposed within the receiving space, the lip and the push plate are blockable with each other in the first direction.

Abstract: A ram assembly is provided. In one embodiment, the ram assembly includes a base ram having a tapered profile and a seal coupled to the base ram in a manner that allows the seal to slide relative to the base ram during operation of the ram assembly. In some instances in which the ram assembly is installed in a blowout preventer, the tapered profile of the base ram can facilitate compression of the seal in multiple directions. Additional systems, devices, and methods are also disclosed.

Abstract: A shutter valve for regulating pressure and controlling fluid flow comprising an actuator ring having a plurality of gear teeth, the gear teeth driven by a mating gear or other means. A plurality of obturator pin bosses, each pin boss affixed within an inside circumference of the actuator ring, the pin boss further comprising a hinge pin aperture. The shutter valve further comprises three or more obturator elements, each obturator element defining a petal shape structure including a tongue and groove feature along at least a portion of an outside circumference thereof, and wherein each obturator element is hingedly coupled to a hinge pin aperture of an obturator pin boss. A hook element is located at an apex of said petal shape structure of each obturator element. The shutter value further includes a housing defining a cavity or holding the actuator ring and the three or more obturator elements.

Abstract: An apparatus for containing pressure associated with a well includes a ram fluid chamber, a ram piston, and an intensifier piston within a housing. The ram piston has ends associated with a ram and with the ram fluid chamber. The intensifier piston has ends associated with the ram fluid chamber and a fluid source. The end of the intensifier piston associated with the fluid source has a larger surface area than the end associated with the ram fluid chamber. Fluid from the fluid source applies a first pressure to the second end of the intensifier piston to move the intensifier piston. Movement of the intensifier piston applies a second pressure greater than the first pressure to fluid in the ram fluid chamber to move the ram piston and associated ram toward a closed position.

Abstract: An apparatus for engaging and moving a ram block. In some embodiments, the apparatus, or ram block changer, includes a support bracket coupled to a blowout preventer and an articulated arm releasably coupled to the ram block. The ram block changer may further include a pivot coupling assembly having a first axis of rotation. The pivot coupling assembly extends through the support bracket and the articulated arm, wherein the articulated arm is rotatable about the first axis of rotation relative to the support bracket. The articulated arm may include a first member receiving the pivot coupling assembly therethrough, a second member coupled to the ram block, and a second pivot coupling assembly having a second axis of rotation spaced apart from the first axis of rotation and extending through the first and second members. The second member is rotatable about the second axis of rotation relative to the first member.

Abstract: A ram assembly of a blowout prevent (BOP) includes a ram shuttle, a ram wedge and a ram seat. The ram shuttle and the ram wedge are slidably positionable in a ram channel of a BOP housing between a retracted and extended position. The ram shuttle has a wedge cavity extending therethrough and an inclined surface thereon. The ram wedge has a tubular cavity therethrough for receiving the tubular. The ram wedge has a corresponding inclined surface engageable with the inclined surface of the ram shuttle, and wedges between the ram shuttle and the housing whereby a force is generated therebetween. The ram seat is positionable in the housing about the passage, and is engageable with the ram wedge and the housing when the ram shuttle and the ram wedge are moved to the extended position whereby a seal is formed therebetween.

Abstract: A ram type blowout preventer having a seal on each ram, extending across the front face, rearwardly and then over the top portion or the bottom portion of the ram. Each ram forms a leading edge portion above or below the front face seal, so as opposing rams move into the extended sealing position, the leading edge portions of the rams press against each other, imparting a generally vertical movement to bring the seals on the front faces into sealing engagement with each other and to energize the seals extending over the top or bottom portions against the ram bores. The front face of each ram may include a portion which is inclined toward the central bore. Rope packing seals may be provided on the rams having a vertical offset at the front faces of the rams such that rope packing seals on opposing front faces seal against each other.

Abstract: A seal assembly for a blowout preventer of a wellsite is provided. The blowout preventer includes a housing and at least one component operatively connectable to the housing. The housing has a bore and a channel therethrough. A tubular is positionable through the bore and engageable therein. The seal assembly includes a seal plate, a seal carrier, and at least one seal. The seal plate is operatively connectable between the housing and the at least one component of the blowout preventer, and has at least one seal groove extending therein. The seal carrier is disposable about a perimeter of the seal plate, has at least one carrier lip disposable in a seal groove(s), and has at least one seal receptacle. The seal is receivably positionable in the seal receptacle, and in sealing engagement with one of the housing, the component, and combinations thereof.

Abstract: A gate valve system for controlling fluid flow having a valve body with a bore through which fluid can flow. The system includes a valve body having a bore to allow fluid to pass through the valve body and further having a cavity defined by substantially parallel innerside walls of the valve body, a gate wherein at least one end of the gate is defined by a radius perimeter. The system also has a bonnet that is removably coupled to a face of the valve body, wherein a portion of an innerside of the bonnet includes a curved surface adapted to mate with the at least one end of the gate defined by the radius perimeter, and an actuation mechanism operationally positioned and removably connected to the gate by way of a thru-hole in the bonnet.

Abstract: A ram-type blowout preventer including an operating piston assembly isolated from wellbore pressure effects is provided. In one embodiment, a blowout preventer includes piston coupled to a ram by a connecting rod, and the connecting rod is inserted into a recess in the ram. A pressure-isolating seal may be provided in the recess between the connecting rod and the ram to isolate the end of the connecting rod within the recess from wellbore pressure in the blowout preventer. Additional systems, devices, and methods are also disclosed.

Abstract: Techniques for shearing a tubular of a wellbore penetrating a subterranean formation with a blowout preventer are provided. The blowout preventer has a housing with a hole therethrough for receiving the tubular. The techniques relate to a blade assembly including a ram block movable between a non-engagement position and an engagement position about the tubular, a blade carried by the ram block for cuttingly engaging the tubular, and a retractable guide carried by the ram block and slidably movable therealong. The restractable guide has a guide surface for urging the tubular into a desired location in the blowout preventer as the ram block moves to the engagement position.