Abstract: An annular seal for sealing an interface between a wellhead housing and a casing hanger. The annular seal includes a central body portion and a first pair of seal legs extending in a first direction from the central body portion. Each of the first pair of seal legs sealingly engages one of the wellhead housing or the casing hanger, and are further energized by bore pressure. The annular seal also includes a second pair of seal legs extending in a second direction from the central body portion. Each of the second pair of seal legs sealingly engages one of the wellhead housing or the casing hanger, and is further energized by annulus pressure.

Abstract: A tubular member connection system includes a box having an inner diameter surface and internal box threads. A pin has an outer diameter surface and external pin threads, the pin threads shaped to mate with the box threads to releasably secure the pin to the box so that the pin and the box are aligned along a common central axis. A slot is located in one of the inner diameter surface and the outer diameter surface, the slot having a pair of sidewalls. An anti-rotation profile is located in the other of the inner diameter surface and the outer diameter surface. A key is sized to fit within the slot and have a key profile shaped to engage the anti-rotation profile and prevent relative rotational movement between the box and the pin.

Abstract: A tubular member connection system includes a pin having a central axis, external pin threads, and an annular pin lip at a shoulder surface. A box has internal box threads and an annular box lip at an end surface of the box. The box threads are shaped to mate with the pin threads to releasably secure the pin to the box. A recess is formed in an outer diameter surface of the pin and extends in an axial direction from the pin lip. An anti-rotation key is located within the recess and has a row of teeth along an outer edge. A fastener retains the anti-rotation key in the recess. A circumferentially extending series of grooves on the box lip are sized to engage the teeth and resist a rotation of the pin relative to the box in an unscrewing direction when the pin is releasably secured to the box.

Abstract: Embodiments of the present disclosure include a riser tensioner includes a cylinder barrel, a rod reciprocally carried within the cylinder barrel and having an external end sealingly extending out of a proximal end of the cylinder barrel, and a piston on an interior end of the rod that slides and seals against an inner surface of the cylinder barrel. The tensioner further includes a selectively sealed low pressure chamber in the cylinder barrel between the piston and a distal end of the cylinder barrel and fillable with a low pressure fluid, and a selectively sealed annulus between the rod and the cylinder barrel, the annulus extending between the piston and the proximal end of the cylinder barrel and fillable with an annulus fluid at a pressure higher than the low pressure fluid, thereby urging the piston and rod towards retraction.

Abstract: A tubular member connection system includes a pin having a central axis, external pin threads, and an annular pin lip at a shoulder surface of the pin. A box has internal box threads and an annular box lip at an end surface of the box. The box threads are shaped to mate with the pin threads to releasably secure the pin to the box. A pin recess is formed in an outer diameter surface of the pin, the pin recess extending in an axial direction from the pin lip. A pin key is selectively fastenable within the pin recess, the pin key having pin teeth on an outer edge of the pin key. The box teeth are located in the box. The box teeth selectively mate with the pin teeth and resist rotation of the pin relative to the box.

Abstract: A computer-implemented method is disclosed for characterizing a threaded coupling such as between two tubular members, e.g., casing segments employed in the field of oil and gas recovery. In one embodiment, a virtual model of the coupling is generated, and the virtual model is re-arranged to simulate plastic deformation of at least part of the coupling. The re-arranged model is analyzed to derive a stress/strain distribution of the coupling subject to subsequent loading, and an SAF (stress amplification factor) is determined from the analysis that reflects the effect of cyclic loading of the coupling. The method facilitates a thorough assessment of the performance of the coupling in fatigue.

Abstract: An annular seal for sealing an interface between a wellhead housing and a casing hanger. The annular seal includes a central body portion and a first pair of seal legs extending in a first direction from the central body portion. Each of the first pair of seal legs sealingly engages one of the wellhead housing or the casing hanger, and are further energized by bore pressure. The annular seal also includes a second pair of seal legs extending in a second direction from the central body portion. Each of the second pair of seal legs sealingly engages one of the wellhead housing or the casing hanger, and is further energized by annulus pressure.

Abstract: A tubular member connection system includes a box having an inner diameter surface and internal box threads. A pin has an outer diameter surface and external pin threads, the pin threads shaped to mate with the box threads to releasably secure the pin to the box so that the pin and the box are aligned along a common central axis. A slot is located in one of the inner diameter surface and the outer diameter surface, the slot having a pair of sidewalls. An anti-rotation profile is located in the other of the inner diameter surface and the outer diameter surface. A key is sized to fit within the slot and have a key profile shaped to engage the anti-rotation profile and prevent relative rotational movement between the box and the pin.

Abstract: Embodiments of the present disclosure include a riser tensioner includes a cylinder barrel, a rod reciprocally carried within the cylinder barrel and having an external end sealingly extending out of a proximal end of the cylinder barrel, and a piston on an interior end of the rod that slides and seals against an inner surface of the cylinder barrel. The tensioner further includes a selectively sealed low pressure chamber in the cylinder barrel between the piston and a distal end of the cylinder barrel and fillable with a low pressure fluid, and a selectively sealed annulus between the rod and the cylinder barrel, the annulus extending between the piston and the proximal end of the cylinder barrel and fillable with an annulus fluid at a pressure higher than the low pressure fluid, thereby urging the piston and rod towards retraction.

Abstract: A method for tying back a subsea well assembly to a surface platform and a tieback connector used to perform this operation. The tieback connector includes a mandrel having an axis, external threads, an upward facing lip on an external lower end portion of the mandrel, a backup ring having internal threads engaged with the external threads of the mandrel, a sleeve carried on an outside diameter of the backup ring. When the mandrel is rotated relative to the backup ring, the mandrel moves axially upward relative to the sleeve, deforming an annular seal assembly between the upward facing lip of the mandrel and the load bearing surface of the sleeve, thereby creating a seal between the apparatus and the wellhead housing.

Abstract: A retention system for limiting axial and radial movement of a wellbore lock ring. The retention system includes pins for resisting axial movement of the lock ring and assemblies for limiting radial outward movement of the lock ring. The lock ring circumscribes and couples to a wellbore hanger. The pins project radially from the hanger into the lock ring and into slots, where the slots extend a distance along the inner surface of the lock ring. The assemblies also project radially into the hanger and each have a portion that registers with a channel on a lower end of the lock ring. Lock ring outer radial movement is limited by contact between the portions of the assemblies and inner surfaces of the channels.

Abstract: A tubular member connection system includes a pin having a central axis, external pin threads, and an annular pin lip at a shoulder surface. A box has internal box threads and an annular box lip at an end surface of the box. The box threads are shaped to mate with the pin threads to releasably secure the pin to the box. A recess is formed in an outer diameter surface of the pin and extends in an axial direction from the pin lip. An anti-rotation key is located within the recess and has a row of teeth along an outer edge. A fastener retains the anti-rotation key in the recess. A circumferentially extending series of grooves on the box lip are sized to engage the teeth and resist a rotation of the pin relative to the box in an unscrewing direction when the pin is releasably secured to the box.

Abstract: A tensioner for maintaining a tensile force in a riser extending from a subsea wellhead assembly to a deck of a floating platform includes a hydro-pneumatic assembly having a first section secured to the deck and a second section secured to a support frame. A pivot joint is coupled to the riser and to the support frame, so that the riser is retained axially static with respect to the support frame and is pivotable with respect to the support frame. A guide assembly has at least two guide elements, the guide elements being axially spaced from each other so that when the deck and the support frame move axially relative to each other, the guide assembly restricts relative rotational movement between the deck and the support frame.

Abstract: A tubular member connection system includes a pin having a central axis, external pin threads, and an annular pin lip at a shoulder surface of the pin. A box has internal box threads and an annular box lip at an end surface of the box. The box threads are shaped to mate with the pin threads to releasably secure the pin to the box. A pin recess is formed in an outer diameter surface of the pin, the pin recess extending in an axial direction from the pin lip. A pin key is selectively fastenable within the pin recess, the pin key having pin teeth on an outer edge of the pin key. The box teeth are located in the box. The box teeth selectively mate with the pin teeth and resist rotation of the pin relative to the box.

Abstract: A method for tying back a subsea well assembly to a surface platform and a tieback connector used to perform this operation. The tieback connector includes a mandrel having an axis, external threads, an upward facing lip on an external lower end portion of the mandrel, a backup ring having internal threads engaged with the external threads of the mandrel, a sleeve carried on an outside diameter of the backup ring. When the mandrel is rotated relative to the backup ring, the mandrel moves axially upward relative to the sleeve, deforming an annular seal assembly between the upward facing lip of the mandrel and the load bearing surface of the sleeve, thereby creating a seal between the apparatus and the wellhead housing.

Abstract: An anti-rotation system for use in retaining a threaded connection between a pin and a box. The anti-rotation system includes a key that sets in a recess formed in one of the box or pin. The key is selectively in contact with one of the other of the box or pin, and is activated when the threaded connection begins to decouple. The key is profiled and operates in a cam like fashion to wedge itself between the box and pin when these members begin to decouple and prevents further relative rotation.

Abstract: A tensioner for maintaining a tensile force in a riser extending from a subsea wellhead assembly to a deck of a floating platform includes a hydro-pneumatic assembly having a first section secured to the deck and a second section secured to a support frame. A pivot joint is coupled to the riser and to the support frame, so that the riser is retained axially static with respect to the support frame and is pivotable with respect to the support frame. A guide assembly has at least two guide elements, the guide elements being axially spaced from each other so that when the deck and the support frame move axially relative to each other, the guide assembly restricts relative rotational movement between the deck and the support frame.

Abstract: A collet assembly connects two tubular members with a rotation of an outer sleeve. The collet assembly includes a first tubular member with a grooved outer diameter end. The end is inserted into a collet having grooved inner and outer diameter surfaces, and an outer annular sleeve is threaded onto the collet. A grooved outer diameter end of a second tubular member is inserted into the collet. The outer annular sleeve is rotated relative to the collet. The rotation causes the collet to partially disengage from the outer annular sleeve and fully engage the grooves of the ends of the first tubular member and the second tubular member, thereby securing the first tubular member to the second tubular member.

Abstract: A computer-implemented method is disclosed for characterizing a threaded coupling such as between two tubular members, e.g., casing segments employed in the field of oil and gas recovery. In one embodiment, a virtual model of the coupling is generated, and the virtual model is re-arranged to simulate plastic deformation of at least part of the coupling. The re-arranged model is analyzed to derive a stress/strain distribution of the coupling subject to subsequent loading, and an SAF (stress amplification factor) is determined from the analysis that reflects the effect of cyclic loading of the coupling. The method facilitates a thorough assessment of the performance of the coupling in fatigue.

Abstract: A retention system for limiting axial and radial movement of a wellbore lock ring. The retention system includes pins for resisting axial movement of the lock ring and assemblies for limiting radial outward movement of the lock ring. The lock ring circumscribes and couples to a wellbore hanger. The pins project radially from the hanger into the lock ring and into slots, where the slots extend a distance along the inner surface of the lock ring. The assemblies also project radially into the hanger and each have a portion that registers with a channel on a lower end of the lock ring. Lock ring outer radial movement is limited by contact between the portions of the assemblies and inner surfaces of the channels.