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 push-up tensioner for maintaining a tensile force in a riser having an axis couples to a floating platform and maintains the tensile force while the riser tilts variably from the vertical. The tensioner includes a plurality of cylinders having a lower end pivotally coupled to the deck. The cylinders are substantially perpendicular to the deck in the running position and at an angle to the deck in the tensioning position. After running of the riser, a placement assembly moves the cylinders from the running position to the tensioning position. A tensioner ring is run on the riser proximate to an upper end of the cylinders, and the cylinders are then automatically coupled to the tensioner ring.

Abstract: A riser connector uses a box and upset pin connector threadform design having S-shaped load flanks that provide a variable load angles depending on the radial position along the engaged teeth. This design promotes a load path that changes with position along the axial length of the engaged thread, as well as increasing or decreasing external loads on the connector. The connector also varies radial distention of the pin from the box in a manner that is different from one thread to the next. The threadform uses a combination of thread cuts that vary in shape, pitch, and/or thread cone angle to provide load and stab flanks, as well as a load path, that vary from one axial end of the engaged thread to the other.

Abstract: A hydro-pneumatic tensioner includes a barrel having an inner bore and a pressurized fluid contained within to form at least part of a primary accumulator having a preset volume of gas at a nominal pressure. A piston having a piston rod extending from an aperture in the barrel is slidably carried in the bore of the barrel and is in communication with the pressurized fluid and positioned to increase the fluid pressure when the piston strokes in the direction of the pressurized fluid. A secondary accumulator also has a preset volume of gas at a preselected pressure. A fluid separator maintains functional separation of the fluid volumes of the primary and secondary accumulators when the primary accumulator pressure is less than the preselected secondary accumulator pressure. The fluid separator allows functional combining of the fluid volumes of the primary and secondary accumulators when the primary accumulator pressure equals or is greater than the preselected secondary accumulator pressure.

Abstract: An attachment extends between an outer sleeve and an inner riser pipe where the pipe penetrates the keel of a platform. In one version, the attachment is a conically-shaped with a small diameter ring that engages the riser pipe and a large diameter ring that engages the outer sleeve. This attachment has elements that are very flexible in bending but relatively stiff and strong in axial load. Other versions include flat rings where lateral load is taken directly into tension and compression in the beams, allowing for relatively high lateral load transfer. Both the conically-shaped attachment and the flat ring have a number of variations that provide low bending stiffness but high axial stiffness of the elements. Depending on whether resistance to axial loads, lateral loads, or resistance to combination of both loads is desired, the attachment and the flat ring may be used alone or in combination.

Abstract: An internal tieback connector for connecting a riser from a platform to a subsea wellhead having internal grooves and a casing hanger therein. The connector has an inner body which carries a lower housing adapted to land on the wellhead. A plurality of dogs abut the lower housing and are adapted to engage and lift the inner body relative to the lower housing. An upper housing is carried on the inner body and adapted to force the dogs inward into engagement with the inner body. A plurality of latch members are carried on the inner body and are adapted to engage the internal grooves when the internal is moved upward relative to the lower housing.