Systems and methods include a system for controlling a downhole multi-circuit switch using a downhole actuator mechanism. A command is sent, by a surface controller coupled to downhole electrically-powered equipment in a wellbore of a well, to change electrical power flow in a multi-circuit switch to a specified position of multiple positions. A connection between the surface controller and the downhole electrically-powered equipment includes at least two separate input electrical connections for supplying electrical power to the downhole electrically-powered equipment. The command is received by a downhole actuator mechanism from the surface controller. The command indicates to switch from a first electrical connection of the at least two separate input electrical connections to a second electrical connection of the at least two separate input electrical connections. The multi-circuit switch is switched by the downhole actuator mechanism based on the command to change a power source of the downhole electrically-powered equipment, including isolating a first input electrical connection.

An independently mountable sensor system for a wet-mateable subsea connector or a dry-mateable subsea connector having at least one of a receptacle connector body or a plug connector body with a pressure vessel; one or more sensors, a power source, a transmitter, a processor and a memory within the pressure vessel. The pressure inside the pressure vessel is maintained at a predetermined pressure and an antenna is provided in the sensor system. The pressure vessel includes an electromagnetically transparent section to permit electromagnetic waves to pass between the sensor system and an external receiver. The sensor system is configured to be mounted between a back end and a front end of the receptacle connector body, or between a back end and a front end of the plug connector body; or configured to be mounted to the connector body back end.

A suction anchor for a subsea well is provided. The suction anchor includes a wellhead support structure. The wellhead support structure is at least in part external of the internal volume of the suction anchor.

A suction anchor for a subsea well is provided. The suction anchor includes a wellhead support structure. The wellhead support structure is at least in part external of the internal volume of the suction anchor.

A subsea wellhead assembly 1 comprises: a subsea wellhead 2; a template 6 associated with the wellhead; subsea riser system equipment 4 connected to the wellhead and one or more connection members. The subsea riser system equipment 4 is also connected to the template 6 by the one or more connection members so that lateral support is provided to the subsea riser system equipment 4 from the template. A method of installing the subsea wellhead assembly 1 is also provided.

A subsea wellhead assembly 1 comprises: a subsea wellhead 2; a template 6 associated with the wellhead; subsea riser system equipment 4 connected to the wellhead and one or more connection members. The subsea riser system equipment 4 is also connected to the template 6 by the one or more connection members so that lateral support is provided to the subsea riser system equipment 4 from the template. A method of installing the subsea wellhead assembly 1 is also provided.

A choke and kill system, and a method of adapting a low pressure drilling rig for use in a high pressure application are described. The system has a low pressure stack and a high pressure blowout preventer stack fluidly connected to the low pressure stack. A choke is fluidly connected to a low pressure choke line of the low pressure stack and is connected to a high pressure choke line of the high pressure blowout preventer stack. The choke is adapted to reduce the pressure from the high pressure choke line to the low pressure choke line.

A choke and kill system, and a method of adapting a low pressure drilling rig for use in a high pressure application are described. The system has a low pressure stack and a high pressure blowout preventer stack fluidly connected to the low pressure stack. A choke is fluidly connected to a low pressure choke line of the low pressure stack and is connected to a high pressure choke line of the high pressure blowout preventer stack. The choke is adapted to reduce the pressure from the high pressure choke line to the low pressure choke line.

A tool (1) for cementing an annulus in a subsea oil or gas well, and methods for using the tool are provided. The tool includes a safety module (2) providing fluid communication between an umbilical and a perforation and circulation module (4) mounted below it. The safety module (2) includes a mechanical lock for connection to a well head. The perforation and circulation module includes upper and lower seals (6, 8) for sealing to the inner surface of a casing; an upper perforating device (14) mounted between the seals; a lower perforating device (16) mounted below the lower seal (8); and supply (S) and return (R) fluid flow paths for circulating fluid from the safety module (2). A diversion means (20) is provided in the supply fluid flow path, operable to redirect fluid supplied to the supply fluid flow path to a space defined between the upper and lower seals (6, 8).

A tool (1) for cementing an annulus in a subsea oil or gas well, and methods for using the tool are provided. The tool includes a safety module (2) providing fluid communication between an umbilical and a perforation and circulation module (4) mounted below it. The safety module (2) includes a mechanical lock for connection to a well head. The perforation and circulation module includes upper and lower seals (6, 8) for sealing to the inner surface of a casing; an upper perforating device (14) mounted between the seals; a lower perforating device (16) mounted below the lower seal (8); and supply (S) and return (R) fluid flow paths for circulating fluid from the safety module (2). A diversion means (20) is provided in the supply fluid flow path, operable to redirect fluid supplied to the supply fluid flow path to a space defined between the upper and lower seals (6, 8).