Abstract: A wellhead has, instead of a conventional Christmas tree, a spool tree (34) in which a tubing hanger (54) is landed at a predetermined angular orientation. As the tubing string can be pulled without disturbing the tree, many advantages follow, including access to the production casing hanger (21) for monitoring production casing annulus pressure, and the introduction of larger tools into the well hole without breaching the integrity of the well.

Abstract: A wellhead has, instead of a conventional Christmas tree, a spool tree (34) in which a tubing hanger (54) is landed at a predetermined angular orientation. As the tubing string can be pulled without disturbing the tree, many advantages follow, including access to the production casing hanger (21) for monitoring production casing annulus pressure, and the introduction of larger tools into the well hole without breaching the integrity of the well.

Abstract: An underwater well system in which an initially vertical drilling riser conduit (5A) is fixed by a template (7,13,15) at the seabed (6) in a non-vertical orientation. Drilling is carried out through wellhead (30) in the template which also includes a valve tree (28) allowing the production fluid to be brought to the surface along a line separate from the drilling riser conduit. The template may be a junction template allowing several wells to be drilled from a single template, or allowing the template to be connected by one or more drilling conduits (12,14) to further templates such that a wide area of the seabed can be covered for a single drilling riser conduit.

Abstract: The consequences of any failure of a blow out preventer assembly to operate correctly in an emergency can be far reaching. Thus, there is provided an apparatus for registering parameters in the bore of a member which is, in use, connected to a pressurised housing, the apparatus comprising: an electro-control package for attachment, in use, to the member; a test assembly placed, in use, in the member; the electro-control package and the test assembly having means for sending signals to and receiving signals from one another.

Abstract: An underwater well system in which an initially vertical drilling riser conduit (5A) is fixed by a template at the seabed in a non-vertical orientation. Drilling is carried out through wellhead in the template which also includes a valve tree allowing the production fluid to be brought to the surface along a line separate from the drilling riser conduit. The template may be a junction template allowing several wells to be drilled from a single template, or allowing the template to be connected by one or more drilling conduits to further templates such that a wide area of the seabed can be covered for a single drilling riser conduit.

Abstract: A method of drilling an offshore underwater well comprising the steps of installing a riser conduit so that it is substantially vertically supported at a production deck. The riser conduit deviates progressively further from the vertical with increasing sea depth, so that its end can be anchored at the seabed by a skid either at an oblique angle so that drilling into the seabed can be carried out at the oblique angle, or horizontally, so that the riser conduit can extend some considerable distance across the seabed before drilling is carried out.

Abstract: A method of drilling an offshore underwater well comprising the steps of installing a riser conduit so that it is substantially vertically supported at a production deck. The riser conduit deviates progressively further from the vertical with increasing sea depth, so that its end can be anchored at the seabed by a skid either at an oblique angle so that drilling into the seabed can be carried out at the oblique angle, or horizontally, so that the riser conduit can extend some considerable distance across the seabed before drilling is carried out.

Abstract: A method of drilling an offshore underwater well comprising the steps of installing a riser conduit (5) so that it is substantially vertically supported at a production deck (1,25). The riser conduit (5) deviates progressively further from the vertical with increasing sea depth, so that its end can be anchored at the seabed (6) by a skid (7) either at an oblique angle so that drilling into the seabed can be carried out at the oblique angle, or horizontally, so that the riser conduit can extend some considerable distance across the seabed (6) before drilling is carried out.

Abstract: A rotary electric actuator module has a plurality of actuators for actuating a device in a subsea wellhead assembly. The module is arranged to receive primary power and control signals from an external source in order to actuate the subsea devices. Each actuator in the module has a back-up power supply, each power supply having a self-contained electrical storage unit providing a source of secondary power. Each actuator has a motor driven by the electrical storage unit. A control system is provided to detect the interruption of the primary power or the control signals and, if the subsea device is in an unsafe operating position, cause the subsea device to move into a safe position using the secondary power.

Abstract: An electrical connection across a peripheral surface through a sealed enclosure (34A) in a radial plane between a tubing hanger (5) and a surrounding support member (3). The connection includes a coupling element (17) in the tubing hanger (5) and an electrical contact supporting shuttle (20) which can reciprocate from a position wholly within the support member (3), across the interface and into electrical connection with the coupling element (17), without producing any movement of a conductor cable (9, 10, 11, 15) leading into a sealed enclosure (34A) within the support. In certain embodiments, the shuttle (20) is driven by threaded engagement with a rotatable drive sleeve (30) and includes a sleeve (21) that is reciprocated over a stationary power core (22). The shuttle (20) is also filled with a dielectric gel (26) contained within a flexible bladder (25). A sensor contact (35) can be used to indicate full retraction of the shuttle (20).

Abstract: A wellhead has, instead of a conventional Christmas tree, a spool tree (34) in which a tubing hanger (54) is landed at a predetermined angular orientation. As the tubing string can be pulled without disturbing the tree, many advantages follow, including access to the production casing hanger (21) for monitoring production casing annulus pressure, and the introduction of larger tools into the well hole without breaching the integrity of the well.