Abstract: A system for use in controlling a hydrocarbon production well has a: computer at a control location remote from a well tree of the well. A processor at the well tree applies control signals to and receives signals from devices of the well tree. The processor also receives further signals associated with the operation of the well. A bi-directional communication link extends between the remote computer and the well tree processor. The well tree further has a communications router coupled with the processor and receiver, for multiplexing the signals from devices at the well head and the further signals on to the bi-directional link.

Abstract: A communications device for underwater use includes an umbilical which contains a length of optical fibre for carrying communications signals. The umbilical also has an optical amplifier provided along said length for boosting the intensity of said signals, and an electrical power line for supplying power to the amplifier. Additionally, the umbilical has a connection device for splicing two cables, each cable carrying a length of optical fibre for carrying communications signals. The connection device has a housing having two ports for accepting respective cables, and an optical amplifier for boosting the intensity of said signals, the amplifier being supplied with power by an electrical power line carried by at least one of the cables.

Abstract: A hydraulic control system for controlling an external device (4) at a well installation includes a control module (2) for generating electrical and/or optical control signals. A control pod (8) receives the control signals, the control pod controlling the external device. A hydraulic line (10) links the control pod to the external device (4) for controlling it.