A control system for automatically operating a well control device located in a subsea blow-out preventer (BOP), has a first control unit and a second control unit. The first control unit is connected to the second control unit and issues an activation command to the second control unit to cause it to trigger actuation of the well control device, and the first control unit is configured to automatically issue the activation command to the second control unit on detecting issue of the signal indicative of a requirement to trigger actuation of the subsea BOP shear mechanism.

A method of installing or removing a subsea wellhead assembly is provided. The method comprising providing a suction anchor that in use acts as a subsea well foundation, wherein the suction anchor comprises an outer suction skirt; and an inner member, wherein the inner member comprises a high pressure wellhead housing; and installing or removing the suction anchor together with the high pressure wellhead housing on or from a seabed.

A method of installing or removing a subsea wellhead assembly is provided. The method comprising providing a suction anchor that in use acts as a subsea well foundation, wherein the suction anchor comprises an outer suction skirt; and an inner member, wherein the inner member comprises a high pressure wellhead housing; and installing or removing the suction anchor together with the high pressure wellhead housing on or from a seabed.

A hydraulic boosting and regulating system includes an intensifier circuit and a regulator and employs low leak, low crossover valves.

A BOP system is provided with sensors distributed along a length of a subsea blowout preventer to monitor objects within a blowout preventer and measure critical parameters. A subsea computer is programmed to detect a speed and direction of an object within the BOP. The computer is programmed to detect movement of an object that is not produced by the drilling rig.

A wellhead system includes a wellhead including a position sensor disposed in an inner surface of the wellhead, and a wellhead component to be installed in the wellhead, the wellhead component including a position indicator disposed in an outer surface of the wellhead component, wherein the position sensor is configured to transmit a position signal in response to the wellhead component entering into a predetermined aligned position in the wellhead.

A subsea well intervention method implemented on a well (200) from a floating vessel (100), said floating vessel not comprising a derrick, the method comprising a step of connecting a power line (207) directly between a remotely operated vehicle (206) and the blowout preventer module (202) for powering the blowout preventer module, the remotely operated vehicle (206) being connected to a control unit (107) located on the floating vessel via a remotely operated vehicle umbilical (106).

The invention relates to the drilling of subsurface oil and gas wells and the installation of subsurface equipment (11). A lifting vessel 7 brings heavy equipment such as Xmas trees or manifolds and wet parks this equipment (11) on the seafloor (5) during good weather when the significant wave height is low. The equipment (11), once it is underwater, has much lower weight and may easily be moved into place onto a wellhead (10) at an appropriate time using lower capacity lifting gear. The timing of this operation is much less sensitive to weather conditions because the equipment does not need to pass through the splash zone (sea surface). This makes for efficient use of expensive drilling rig time, and allows for acceleration of production of first wells on the template as critical heavy lifts could not else be done until rig has left the location. (FIG. 1).

The invention relates to the drilling of subsurface oil and gas wells and the installation of subsurface equipment (11). A lifting vessel 7 brings heavy equipment such as Xmas trees or manifolds and wet parks this equipment (11) on the seafloor (5) during good weather when the significant wave height is low. The equipment (11), once it is underwater, has much lower weight and may easily be moved into place onto a wellhead (10) at an appropriate time using lower capacity lifting gear. The timing of this operation is much less sensitive to weather conditions because the equipment does not need to pass through the splash zone (sea surface). This makes for efficient use of expensive drilling rig time, and allows for acceleration of production of first wells on the template as critical heavy lifts could not else be done until rig has left the location. (FIG. 1).

A wellbore system includes a tubing hanger positioned within a wellhead and a Christmas tree (XT) coupled to the tubing hanger. The wellbore system also includes an annulus isolation device (AID). The AID includes a manual actuator configured to drive a wedge in a linear direction. The AID also includes a mating wedge arranged within an annulus flow path, the mating wedge configured to receive a force responsive to movement of the wedge. The AID further includes a stab coupled to the mating wedge, the stab configured to move in an axially downward direction responsive to movement of the mating wedge, the stab having a slotted portion moveable into alignment with an annulus passage to permit flow into the annulus flow path.