Abstract: A section milling system may include an anchor secured to a downhole end of a coiled tubing. The anchor is configured to expand radially outward to set the anchor at a desired downhole position and restrain rotation of the coiled tubing. The section milling system also includes a reamer positioned downhole from the anchor. The reamer having extendable cutting arms configured to extend in response to fluid flowing through the reamer. Additionally, the section milling system includes a motor configured to rotate in response to fluid flowing through the motor, and rotation of the motor is configured to drive rotation of the cutting arms of the reamer to mill wellbore casing positioned adjacent the reamer. The section milling system further includes an actuation feature configured to move the reamer to mill along a wellbore in the uphole direction.

Abstract: An intervention package for servicing a subsea well has an emergency disconnect package mountable to a riser and a lower riser package connectable to the subsea well. One or more compact cutting devices are utilized on the lower riser package. The intervention package can be used without a BOP. The compact cutting device has a throughbore going through the body that is connectable to the wellbore. Mounted in the body are two gates that are continuously in contact with each other. Each gate has a blank portion and an opening. For each gate, a piston and piston chamber are on the opposite side of gate from the bore that goes through the body.

Abstract: A safety valve for extraction wells, configured to be installed on a well head and to enclose a tubular material portion inserted inside the well. The tubular material is internally hollow to contain and transport substances extracted from the well. The safety valve includes: a central hole through which the tubular material passes; a blocking system configured to keep the tubular material to be cut fixed with respect to the safety valve; a cutting and closing group configured to cut and close the well under certain operative conditions; and a sealing mechanism configured to effect watertight closing of the well, after the cutting. The cutting and closing group includes a hole saw housed in a respective chamber of the cutting and closing group, rotated by a motorized actuator, and configured to move in a controlled mode along a substantially orthogonal direction with respect to a development direction of the well.

Abstract: A blowout preventer (“BOP”) includes a housing comprising a vertical bore extending through the housing and ram cavities intersecting the bore and a pair of opposing ram assemblies, with each ram assembly movably positionable within a ram cavity and comprising a side packer assembly. The side packer assembly comprises an upper plate, a lower plate, an elastomeric body positioned between the upper plate and the lower plate and comprising elastomeric material, and a support member positioned between the upper plate and the lower plate and configured to confine movement of the elastomeric body when sealing.

Abstract: An angle-cut shear ram blowout preventer system containing an angle-cut shear ram inside a ram housing with a ram housing bore. A ram cylinder pressure housing can be secured to the ram housing, wherein the ram cylinder pressure housing can be fluidly connected to a hydraulic pressure source or a pneumatic pressure source. A piston in the ram cylinder pressure housing can be fluidly connected to the hydraulic pressure source or the pneumatic pressure source. A taper can be extended from the ram housing bore into a through bore to simultaneously sever a pipe in a well and seal the well once the pipe is severed without requiring additional downhole tools.

Abstract: An apparatus for cutting a tubular part includes a carrying body configured to receive an end of the tubular part. In addition, the apparatus includes a cutting assembly disposed in the carrying body. The cutting assembly includes a continuous ring configured to be rotated relative to the carrying body. Further, the apparatus includes a first cutting element pivotally attached to the continuation ring. The first cutting element includes a cutting edge configured to engage and cut the tubular part. Still further, the apparatus includes a first actuator coupled to the first cutting element and configured to pivot the first cutting element between a retracted position and a cutting position. The apparatus also includes at least one sensor configured to measure a position of the first cutting element and a force applied to the first cutting element.

Abstract: A downhole tool includes a radial expansion assembly deployed about, and configured to rotate substantially freely with respect to, a tool mandrel. The expansion assembly includes at least one stabilizer block configured to extend radially outward from the mandrel into contact with a wellbore casing string. When deployed between uphole and downhole cones, the stabilizer block includes a plurality of angled splines configured to engage corresponding splines on the cones. Relative axial motion between the stabilizer block and the cones causes a corresponding radial extension or retraction of the stabilizer block.

Abstract: A multi-barrier seal system, including, a first seal assembly configured to provide a first sealing barrier between an auxiliary line and a mineral extraction system, and a second seal assembly configured to provide a second sealing barrier between the auxiliary line and the mineral extraction system, wherein the second seal assembly is configured to shear through the auxiliary line.

Abstract: A rigless abandonment system including a surface vessel having an attached lifting device and a moonpool. The system further includes a cutting module configured to connect to a subsea wellhead, the cutting module having a wellhead connector having an actuatable lock and release mechanism, a motor assembly, and a cutter. An umbilical line connects the cutting module to the surface vessel, wherein the lifting device is used to raise and lower the cutting module connected to the surface vessel through the moonpool. A method for performing rigless casing cutting and wellhead removal operations, the method includes positioning a surface vessel above a subsea wellhead, where the surface vessel has a moonpool and a lifting device. The method further includes providing a cutting module, and deploying the cutting module through the moonpool, wherein the cutting module is connected to the surface vessel by an umbilical line.

Abstract: A method of abandoning a borehole includes, running a tool into the borehole, cutting a casing with a first portion of the tool, reaming the borehole in an area where the casing has been cut with a second portion of the tool, disconnecting a drillstring from the tool, and cementing the borehole through the drillstring.

Abstract: There is provided a high power laser riser blowout preventer system and controller for operation thereof. The system utilizes high power laser cutters that are associated with the riser and the blowout preventer to provide an integrated operation to quickly weaken or cut tubulars to address potential emergency and emergency situations that can arise during deep sea drilling.

Abstract: Systems and methods for quick access and control of a blown-out well or well that is flowing uncontrollably into the environment. Preferred embodiments of the present invention provide a re-entry of the casing of the blown-out well below the mud line and the inoperable blowout preventer. The present invention also provides a method to re-enter a production, or injection well, either subsea below the mud line or above the mud line for surface facility applications. According to a preferred embodiment of the present invention, a miniature wellbore is created from the outer casing through the various smaller casing strings into the final wellbore to protect the structural integrity of the well. Once the casing is safely penetrated, coil tubing and or kill weight fluid can be introduced to stop the uncontrolled flow of reservoir fluid. The well can then be sealed with cement and abandoned as normal practice dictates.

Abstract: A whipstock system for drilling a wellbore from a water bottom supported platform having wellbores with conductor pipes disposed through guide slots in a template on the bottom of a body of water includes a whipstock pipe extending from an equipment deck surface on the platform to a stab in sub. The whipstock pipe includes a window and j-slot mechanism for releasably engaging a scab liner. A stab in sub is configured to make mechanical connection between the whipstock pipe and a surface of a wellbore conductor pipe cut proximate the water bottom. The system includes a scab liner extending from the window to the water bottom when the stab in sub is engaged to the cut conductor pipe. The window is disposed above the water bottom. The scab liner configured to enable drilling a wellbore surface hole therethrough to a selected depth of a surface casing.

Abstract: A blade assembly of a blowout preventer for shearing a tubular of a wellbore penetrating a subterranean formation is provided. The blowout preventer has a housing with a hole therethrough for receiving the tubular. The blade assembly includes 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, a retractable guide carried by the ram block and slidably movable therealong, and a release mechanism for selectively releasing the guide to move between a guide position for guiding engagement with the tubular and a cutting position a distance behind the blade for permitting the blade to cuttingly engage the tubular.

Abstract: A blowout preventer and flow regulator, comprising blocks, each having a channel and plates to close it. The blocks are placed over a pipe through which oil or other fluid is escaping, so that the pipe is in their channels. Alongside the channel in each block are one or more plates, having diameters somewhat larger than the diameter of the channel. One or more pistons are attached to each of the plates. Explosive charges, or other suitable means, move the pistons to propel the plates across the channel to seal it off and stop the leak. Flanges may limit the pistons' movement. Gears can engage teeth on the pistons to withdraw the plates from the channel, to reopen it and allow the flow of oil or other fluid to resume. Plates may be withdrawn part way from the channel, to reduce and control the flow, without cutting it off completely.

Abstract: A combination blowout preventer and recovery device, comprising a lower part that is placed over a well pipe, and an upper part having a channel and plates to close it. The large end of the valve is placed over a well pipe through which fluid is flowing out. The small end of the valve is connected to the channel. A sleeve connected to the return pipe is placed over the well pipe. Positioning rings are attached to a high pressure pipe, that can fit inside the well pipe. Grinders remove matter from the well pipe. Pistons are attached to each of the plates. The pistons propel the plates across the channel to seal it off and stop the leak. Flanges may limit the pistons' movement. Gears can engage teeth on the pistons to withdraw the plates from the channel, to reopen it and allow the flow of fluid to resume.

Abstract: There is provided a high power laser-riser blowout preventer package and laser module for use with a subsea riser. The laser module and laser-riser package use high power laser energy to quickly cut the riser permitting an offshore drilling rig to quickly, and in a controlled manner disconnect from a blowout preventer.

Abstract: A subsea well safing method and apparatus adapted to secure a subsea well in the event of a perceived blowout in a manner to mitigate the environmental damage and the physical damage to the subsea wellhead equipment to promote the ability to reconnect and recover control of the well. The safing assembly is adapted to connect the marine riser to the BOP stack. Pursuant to a safing sequence, the well tubular is secured in the upper and lower safing assemblies and the tubular is then sheared between the locations at which it has been secured. Subsequently, an ejection device is actuated to physically separate the upper safing assembly and connected marine riser from the lower safing assembly that is connected to the BOP stack.

Abstract: There is provided a high power laser assisted blowout preventer and methods of use. In particular, there are provided systems and assemblies for utilizing high power laser energy within a blowout preventer to cut tubulars that are present within the bore of the blowout prevent, reducing the risk that such tubulars will inhibit the ability of the blowout preventer to seal a well.

Abstract: Methods and apparatuses for severing a wellbore tubular, the apparatus, in certain aspects, including: a first member movable toward a tubular to be severed; a second member with a second blade disposed opposite to the first member and movable toward the tubular; a first blade on the first member having a projection projecting from a center of a blade body with point structure on the projection for puncturing the tubular and cutting surfaces on the projection for cutting the tubular; and cutting surfaces, as needed, on the blade body adjacent the projection for cutting the tubular.

Abstract: There is provided a high power laser riser blowout preventer system and controller for operation thereof. The system utilizes high power laser cutters that are associated with the riser and the blowout preventer to provided an integrated operation to quickly weaken or cut tubulars to address potential emergency and emergency situations that can arise during deep sea drilling.

Abstract: There is provided a high power shear laser module, which can be readily included in a blowout preventer stack. The shear laser module as the capability of delivering high power laser energy to a tubular within a blowout preventer cavity, cutting the tubular and thus reducing the likelihood that the tubular will inhibit the ability of the blowout preventer to seal off a well.

Abstract: Techniques for severing a tubular of a wellbore penetrating a subterranean formation are provided. A blade is extendable by a ram of a blowout preventer positionable about the tubular. The blade includes a blade body having a front face on a side thereof facing the tubular. At least a portion of the front face has a vertical surface and at least a portion of the front face has an inclined surface. The vertical surface is perpendicular to a bottom surface of the blade body. The blade body includes a loading surface on an opposite side of the blade body to the front face. The loading surface is receivable by the ram. The blade also includes a cutting surface along at least a portion of the front face for engagement with the tubular, and a piercing point along the front face for piercing the tubular. The piercing point has a tip extending a distance from the cutting surface.

Abstract: A system and methodology facilitates utilization of a valve of a type which may be used as a subsea test tree. The valve comprises a valve element pivotably mounted in a housing having a passageway therethrough. The valve element may be actuated between an open position and a closed position blocking the passageway. A cutter is disposed along a first surface of the valve element and a seal system is positioned for engagement with a second surface of the valve element to provide separate cutting and sealing surfaces. Actuating the valve element from the open position to the closed position enables cutting of a conveyance, that may be positioned through the passageway, while simultaneously forming a seal along a separate surface to sealingly block the passageway.

Abstract: There is provided a high power shear laser module, which can be readily included in a blowout preventer stack. The shear laser module as the capability of delivering high power laser energy to a tubular within a blowout preventer cavity, cutting the tubular and thus reducing the likelihood that the tubular will inhibit the ability of the blowout preventer to seal off a well.

Abstract: A blow out preventer comprises a valve casing assembly, a tubing cutter, a hydraulic cylinder and piston, and a linkage assembly. The valve casing assembly has a first port and a second port. The ports are in axial alignment along a longitudinal axis extending between the ports. The well tubing is run through the ports and transversely through the tubing cutter. The tubing cutter is rotatably positioned in the casing assembly and is rotatable from a first position to a second position. The tubing cutter has an axis of rotation which is transverse to the longitudinal axis of the valve casing assembly. The piston is annularly shaped and moves parallel to the longitudinal axis of the valve casing. Linkage between the piston and the tubing cutter converts the axial movement of the piston into rotational movement of the tubing cutter to shear the tubing when needed. When the tubing has been sheared, a seal is formed between a face of the tubing cutter and a valve seat in the valve casing assembly.

Abstract: The present invention generally relates to methods and apparatus for subsea well intervention operations, including retrieval of a wellhead from a subsea well. In one aspect, a method of performing an operation in a subsea well is provided. The method comprising the step of positioning a tool proximate a subsea wellhead. The tool has at least one grip member and the tool is attached to a downhole assembly. The method also comprising the step of clamping the tool to the subsea wellhead by moving the at least one grip member into engagement with a profile on the subsea wellhead. The method further comprising the step of applying an upward force to the tool thereby enhancing the grip between the grip member and the profile on the subsea wellhead. Additionally, the method comprising the step of performing the operation in the subsea well by utilizing the downhole assembly.

Abstract: Systems can be configured to move a ram block in a blowout preventer. The system includes: a first bank of accumulators configured to provide a first pressure to move the ram block; a second bank of accumulators configured to provide a second pressure to move the ram block, wherein the second pressure is greater than the first pressure; and a controller configured to sequentially control the first bank of accumulators to apply pressure to move the ram block and to then control the second bank of accumulators to move the ram block after the first bank of accumulators has moved the ram block a first distance.

Abstract: removable blowout recovery valve. The large end of the valve (or funnel) is placed over a well pipe (or other pipe) through which oil (or other fluid) is flowing out. The small end of the valve is connected to a return pipe. A high pressure pipe with a smaller diameter is inserted into the well pipe. A sleeve connected to the return pipe is placed over the well pipe. A locking collar is attached to the sleeve. Positioning rings are attached to the high pressure pipe, that can fit inside the well pipe. A sharp edge extends from the sleeve, by which irregularities in the well pipe can be cut. Lasers or other cutting devices are attached to extension arms, that can also cut irregularities in the well pipe. The slope of the valve can be changed. The valve can be removed and raised with the aid of floats.

Abstract: Wellhead-based systems, apparatus, and methods for controlling a well are provided. During a failure of an emergency system such as a blowout provider, a wellhead based emergency control apparatus according to an embodiment of the invention can be employed to control the well. A casing strings compression assembly can radially compress each of the casing strings and/or drilling pipe extending through the wellhead housing to restrict or stop well fluid passage. A casing strings penetrator of an emergency well fluid diversion assembly can also or alternatively be employed to form an aperture in the casing strings. A diverter, integral with or connected to the penetrator, is extended through an aperture in a side of the wellhead housing and one or more of the apertures cut by the penetrator to divert well fluid from within the wellhead housing through a passageway in the diverter and to an external conduit.

Abstract: There is provided systems, methods and apparatus for the use of directed energy, including high power laser energy, in conjunction with mechanical shearing, sealing and closing devices to provide reduced mechanical energy well control systems and techniques.

Abstract: Method and water submerged device for generating a force under water. The device includes a low pressure recipient configured to contain a volume of a first fluid at a low pressure volume, an inlet connected to the low pressure recipient and configured to exchange a second fluid with an external enclosure, and a valve connected to the external enclosure and the inlet and configured to separate a pressure source in the external enclosure from the low pressure recipient. When the valve is open, such that there is a flow communication between the external enclosure and the low pressure recipient, a pressure imbalance occurs in the external enclosure which generates the force and the second fluid from the external enclosure enters the low pressure recipient and compresses the first fluid.

Abstract: Methods and apparatuses for severing a wellbore tubular, the apparatus, in certain aspects, including: a first member movable toward a tubular to be severed; a second member with a second blade disposed opposite to the first member and movable toward the tubular; a first blade on the first member having a projection projecting from a center of a blade body with point structure on the projection for puncturing the tubular and cutting surfaces on the projection for cutting the tubular; and cutting surfaces, as needed, on the blade body adjacent the projection for cutting the tubular.

Abstract: A subsea cutting device for a subsea blow-out preventer or wellhead comprises a tubular body having an axial throughbore, and configured to be fitted to a casing string, the cutting device further comprising a shearing mechanism in the form of a radial cutting system rotatably mounted within a pressure-containing housing, and comprising a plurality of movable cutters arranged around the throughbore and configured for deployment during rotation successively inwards. The cutting device is useful in a subsea shut off device which is latched to a template at surface and run to the sea floor on a casing string which is drilled into place and converted into a riser on a single trip. For the event when emergency disconnection is required, the device may be used to cut the casing and seal in the well. The system then allows a conventional subsea reconnection of the riser.

Abstract: A method and system for repairing, replacing or installing an underground pipeline using an appropriate tool head. A coolant, preferably a cryogenic liquid, is injected in front of the tool head to embrittle or otherwise reduce the toughness of the material ahead of the tool head. The method and system of this invention are particularly suitable for use in connection with pipe splitting and pipe bursting, where a pig disposed within the underground pipeline is connected with the appropriate tool head forming a space between the pig and the tool head into which the coolant is introduced. The pipe between the pig and the tool head is embrittled by the coolant, reducing the resistance of a pipe to splitting or bursting which, in turn, reduces the force required for the pig to pull the tool head as the pig is motivated through the pipe.

Abstract: A well drilling system including: an annular valve; a well casing in fluid communication with the annular valve; a first check valve in fluid communication with the annular valve; a hydraulic cylinder including a first chamber having an inlet and an outlet, wherein the inlet of the first chamber is in fluid communication with an outlet of the first check valve; and a transfer unit including an inlet and an outlet, wherein the inlet of the transfer unit is in fluid communication with the outlet of the first chamber, the outlet of the transfer unit is in fluid communication with an inlet of a second check valve, and an outlet of the second check valve is in fluid communication with the annular valve.

Abstract: The invention relates to techniques for severing a tubular. A blowout preventer is provided with a housing having a bore therethrough for receiving the tubular, an actuator positionable in the housing, and a plurality of cutting tools positionable in the housing and selectively movable into an actuated position with the actuator. Each of the cutting tools have a base supportable by the actuator and selectively movable thereby, and a cutting head supported by the base. The cutting head comprising a tip having a piecing point at an end thereof and at least one cutting surface. The piercing point pierces the tubular and the cutting surfaces taper away from the piercing point for cutting through the tubular whereby the cutting head passes through tubular.

Abstract: The present invention generally relates to methods and apparatus for subsea well intervention operations, including retrieval of a wellhead from a subsea well. In one aspect, a method of performing an operation in a subsea well is provided. The method comprising the step of positioning a tool proximate a subsea wellhead. The tool has at least one grip member and the tool is attached to a downhole assembly. The method also comprising the step of clamping the tool to the subsea wellhead by moving the at least one grip member into engagement with a profile on the subsea wellhead. The method further comprising the step of applying an upward force to the tool thereby enhancing the grip between the grip member and the profile on the subsea wellhead. Additionally, the method comprising the step of performing the operation in the subsea well by utilizing the downhole assembly.

Abstract: The method of providing increased motive force for one or more rams of a subsea blowout preventer comprising providing a one or more pistons connected to the one or more ram, the pistons having a distal side and a proximate side with respect to the ram, providing a tank contain a first pressure less than the ambient pressure of seawater at the location of the subsea blowout preventer, and communicating the first pressure with the proximate side of the one or more pistons to cause or enhance the differential pressure across the one or more pistons to urge the rams toward the center of the bore of the subsea blowout preventer.

Abstract: The present invention generally relates to methods and apparatus for subsea well intervention operations, including retrieval of a wellhead from a subsea well. In one aspect, a method of performing an operation in a subsea well is provided. The method comprising the step of positioning a tool proximate a subsea wellhead. The tool has at least one grip member and the tool is attached to a downhole assembly. The method also comprising the step of clamping the tool to the subsea wellhead by moving the at least one grip member into engagement with a profile on the subsea wellhead. The method further comprising the step of applying an upward force to the tool thereby enhancing the grip between the grip member and the profile on the subsea wellhead. Additionally, the method comprising the step of performing the operation in the subsea well by utilizing the downhole assembly. In another aspect, an apparatus for use in a subsea well is provided.

Abstract: A free falling drop sub carries an explosive tool such as a shaped charge pipe cutter or well perforator. The drop sub includes an aperture plugging element to isolate an upper pipe string from a lower pipe string. An upper pipe string fluid pressure actuated valve element retained by shear pins is released to admit the upper string pressure against a pressure displaced firing pin. Displacement of the firing pin initiates detonation of the explosive tool.

Abstract: There is provided a high power laser-riser blowout preventer package and laser module for use with a subsea riser. The laser module and laser-riser package use high power laser energy to quickly cut the riser permitting an offshore drilling rig to quickly, and in a controlled manner disconnect from a blowout preventer.

Abstract: There is provided a high power laser assisted blowout preventer and methods of use. In particular, there are provided systems and assemblies for utilizing high power laser energy within a blowout preventer to cut tubulars that are present within the bore of the blowout prevent, reducing the risk that such tubulars will inhibit the ability of the blowout preventer to seal a well.

Abstract: A gate valve having a body, a chamber housed in the body, a passage through the body that intersects the chamber, a gate for selectively opening and closing the valve, and a cutting edge on the gate. The cutting edge can sever any lines that may be in the valve and still seal after closing. The gate includes a recess formed to collect cuttings formed while severing the line.

Abstract: An apparatus and method for removing a subsea structure wherein a housing defining a subsea structure receiving space and having a jetting system attached at or near the bottom of the housing is used to form an excavation around the subsea structure to the desired depth and a frame attached to or mounted in the housing carries a cutter assembly which is movable from a first position on the frame to a second position on the frame, the first position being on one side of the subsea structure, the second position being on the opposite side of the subsea structure.

Abstract: The present invention concerns an apparatus for cutting a tubular part (16) extending down into a sea- or ocean bed. The apparatus includes a carrying body (1) adapted to be led over the tubular part (16) that is to be cut, with a cutting assembly placed in the carrying body (1). The cutting assembly includes a ring adapted to be driven in rotation in the carrying body (1). At least one cutting element (6) with a cutting portion (19), is hinged to the ring. At least one actuator (3) is adapted for leading the cutting element (6) between a retracted position and a cutting position against the tubular part (16) that is to be cut. Furthermore it is described an assembly with a cutting apparatus (A) and a carrying body (1) with a least one jaw (15, 28, 29) for fixing and centring the tubular part (16) in relation to the apparatus (A), and a method for subsea cutting of tubular parts (16).

Abstract: The present disclosure generally provides apparatus and methods for removing a subsea well head. The apparatus may include an embedded shear comprising a pile and a shear cutter integrated into the pile. The shear cutter may be mounted within the pile near a lower end thereof. The pile may include a well head conductor receptacle adapted to receive a subsea well head, and the shear cutter may include a shear blade that extends across the well head conductor receptacle when activated. The method may include providing a pile with a shear cutter integrated therein, lowering the pile over the well head, pumping water out of the pile to drive the pile into the seafloor to a desired cutting depth, activating the shear cutter to cut off a portion of the well head, and pumping water into the pile to drive the pile out of the seafloor.

Abstract: A rigless support for a downhole operation, such as cutting of an underwater casing in preparation for plug-and-abandonment. The unit has a movable base that can be positioned on a floating structure, such as a barge or a marine vessel and delivered to the site. A pair of piston rams support a swivel unit therebetween, with the swivel unit being driven by a hydraulic motor and driving a casing cutter.

Abstract: The present invention generally relates to methods and apparatus for subsea well intervention operations, including retrieval of a wellhead from a subsea well. In one aspect, a method of performing an operation in a subsea well is provided. The method comprising the step of positioning a tool proximate a subsea wellhead. The tool has at least one grip member and the tool is attached to a downhole assembly. The method also comprising the step of clamping the tool to the subsea wellhead by moving the at least one grip member into engagement with a profile on the subsea wellhead. The method further comprising the step of applying an upward force to the tool thereby enhancing the grip between the grip member and the profile on the subsea wellhead. Additionally, the method comprising the step of performing the operation in the subsea well by utilizing the downhole assembly. In another aspect, an apparatus for use in a subsea well is provided.

Abstract: The invention relates to a safety joint (10; 100; 200) for a riser consisting of two telescoping parts that are arranged to break in the event of a predetermined axial tension load. The joint also comprises means (21, 41; 121, 141; 221, 241) for closing the passage in the joint in the event of fracture where the means are activated by means of the forces generated during the separation.