Abstract: An internal tree cap having a running configuration and a latched configuration to be selectively secured to a tree spool. The tree cap may include an inner sleeve movable between upper and lower positions. The movement of the inner sleeve to the lower position may simultaneously engage a locking profile within the tree spool and energize a sealing element around the exterior of the tree cap. The tree cap may be a low profile tree cap that is flush with the top of the tree spool when installed. The tree cap may provide a collateral beneficial locking means to secure a tubing hanger within the tree spool. A lower housing may be attached to the tree cap to seal on the exterior of the upper neck of the tubing hanger. The tree cap may include a profile to accept a wireline plug.

Abstract: A drilling head used to seal around a drill pipe while drilling is employed in a subsea location. The drilling head has an inner body located within an outer body. At least one bearing is located between the outer body and the inner body for facilitating the rotation of the inner body relative to the outer body. A seal mounted to a lower portion of the inner body seals around the outer surface of the drill pipe. While lowering the drilling head to the wellhead, a support attached to the drill pipe is inserted into a skirt which surrounds a portion of the seal. The skirt and support are releasably connected using a J-slot mechanism. An inner annulus and an outer annulus are located between the inner and outer bodies, the annuluses containing a lubricating fluid. Helical vanes are located within the inner annulus and affixed to the inner body. The vanes rotate with the inner body for circulating the fluid through the inner and outer annuluses.

Abstract: A subsea wellhead connector has an upper body that abuts the rim of a wellhead member. A hydraulic wellhead connector is carried by the upper body and extends over the wellhead member. The hydraulic wellhead connector carries dogs for moving into an engaged position with a profile on the exterior of the wellhead member. The mating or complementary stepped profile at the top or rim of the wellhead housing is designed to engage at three surfaces. The first surface is the flat surface at the inner diameter. The second surface is the tapered surface at the step. The third surface is the flat surface on the rim from the tapered surface to the outer diameter of the rim. The profiles are dimensioned with bias toward initial contact at the outer diameter flat on the rim of the well housing, second contact is at the inner diameter flat on the rim of the well housing, and the third contact is at the tapered step.

Abstract: A horizontal tree having a vertical bore and a horizontal production passage is landed in a wellhead housing. A tubing hanger lands in the bore and has a vertical passage and a horizontal passage that aligns with that of the tree. A retrievable first plug seals the vertical passage. A tree cap seals in the tree bore above the tubing hanger and has an axial passage. A retrievable second plug having a valve seals the tree cap passage. A vent port extends laterally through the tree cap between its axial passage and outer surface. A pair of seals on the second plug seal above and below the vent port. A tubing annulus passage communicates with the vent port and an annulus passage. The second plug serves as a second pressure barrier to the first plug and blocks the vent port when the valve is closed. The annulus passage is sealed from communication with a void between the plugs. The valve may be opened to release pressure in the void by applying pressure to an upper end of the check valve.

Abstract: A method and apparatus for making an electrical connection through a tubing hanger in a subsea well avoids the need for precise gauging and alignment. The tubing hanger has an electrical receptacle located on its rim and a guide hole also located on the rim. An impression block tool is lowered into the wellhead from the surface to make an impression of the rim to determine the orientation of the guide hole. A carrier is mounted to the tree connector at the surface. The carrier has a guide pin and an electrical connector. The carrier is aligned, then secured to the tree connector so that it can move only a limited amount rotationally. As the tree connector enters the wellhead, the guide pin will enter the guide hole, which is tapered. A limited amount of rotation of the carrier relative to the tree connector allows the electrical connectors to precisely align before contacting each other.

Abstract: An apparatus for connecting a riser to a wellhead housing for a tie-back connection allows connection without rotation or hydraulic actuation. A connector body is mounted to the lower end of the riser for lowering over the wellhead housing. Dogs are carried in the connector body, each having grooves on its interior for mating with grooves formed on the wellhead housing. Guide surfaces in the connector body allow the dogs to retract and extend, but only in directions perpendicular to the upper flanks of the wellhead housing grooves. Springs urge the dogs inwardly and downwardly to lock the connector body to the wellhead housing. A release mechanism allows the connector body to be pulled upwardly and removed from the wellhead housing.

Abstract: A tie-back connector for a subsea well allows the tie-back connection to be made without rotation. A set of threads is located on an inner wall of the outer conduit into which the tie-back connection is to be made. An annular latch is carried by the inner conduit which is being tied back from the surface to the outer conduit. The latch has threads on its exterior which ratchet past the threads on the inner wall as the inner conduit is lowered into the outer conduit. After the threads of the latch are ratcheted fully into alignment with the threads in the outer conduit, the inner conduit is pulled upwardly relative to the latch to secure it in tension. A retainer is actuated when the inner conduit is in the upper position to prevent the inner conduit from moving downwardly again relative to the latch. The inner conduit can be removed by rotation relative to the outer conduit.

Abstract: A diverless subsea flowline connection system includes a plurality of connectors for remotely connecting the end of a bundle of flowlines to the ends of a plurality of bundles of individual flowlines. Guidance components direct the end portion of each bundle of individual flowlines into precise connecting alignment with a corresponding end portion of the bundled flowlines without damage to the connecting seals. The end portion of the bundled flowlines are covered and sealed so that these flowlines can be pulled across a sea floor without damage to their connecting ends. Means are provided for pulling the flowline bundle toward an aligning structure so that the lines can approach the structure from a wide variety of angles and the structure will guide the bundled flowlines into position where they can be aligned exactly with the individual diameter flowlines. This pulling means includes means for connecting a pulling cable to the radial center of a pulling head attached to the ends of the bundled flowlines.

Abstract: A diverless subsea flowline connection system includes connectors for remotely connecting the ends of a first bundle of flowlines to the ends of a second bundle of flowlines and guidance components which direct the end portions of the first bundle of flowlines into precise connecting alignment with the end portions of the second bundle of flowlines without damage to the connecting seals. The ends of the first bundle are covered and sealed so that the flowlines can be pulled across the seafloor without damage to the ends of the flowlines. Means are provided for pulling the first bundle toward an alignment structure so that the lines can approach the structure from a wide variety of angles and the structure will guide the first bundle into exact alignment with the second bundle. This pulling means includes means for connecting a pulling cable to the radial center of a pulling head attached to the ends of the first bundle of flowlines.