Abstract: An electronic module for use as a subsea electronic module (SEM) for an underwater fluid extraction well, as provided. An example of such an SEM includes a plurality of substantially planar electronics cards to operate devices in the SEM. The cards are arranged in a stack such that major faces of each card are oriented substantially parallel to, and coaxial with, major faces of the other cards in the stack. The SEM also includes a substantially planar switch card orientated relative to the stack such that its major faces are oriented substantially parallel to a main axis of the stack and orthogonal to the orientation of the major faces of the electronics cards within the stack. The switch card includes a first Ethernet switch blade configured to control traffic on a LAN area network and a second Ethernet switch blade configured to control traffic on a second LAN.

Abstract: A subsea control module has a casing (1) inside which there is at least one pair of electrodes, there being electronic means (26-33) connected with the electrodes of the or each pair for monitoring at least one electrical characteristic between the electrodes as a result of a fluid to which the electrodes are exposed, the or each pair of electrodes comprising an array (19) in which each electrode of the pair has finger portions interleaved with finger portions of the other electrode.

Abstract: A module for use as a subsea electronic module of a subsea well, comprises an input (7) for receiving signals from a sensor arrangement which senses at least one parameter of a well, the module including a plurality of separate, different electronic circuits (9), each of which is selectable to be in communication with said input and each of which is adapted to co-operate with a respective, different form of such a sensor arrangement.

Abstract: A method of testing an electronics module (11) for an underwater well installation, comprises the steps of: providing a test equipment (7) comprising a processor (8) and a Local Area Network (LAN) switch (9), such that the processor (8) may communicate with the switch (9); providing an electronics module (11) comprising a data acquisition means (12) and a second LAN switch (10), such that the data acquisition means (12) may communicate with the second switch (10); passing test data from the processor (8) to the data acquisition means (12) via the first and second LAN switches (9, 10); and monitoring the response of the electronics module (11) in response to the test data.

Abstract: A system for enabling communication between an underwater fluid extraction facility and a remote location comprises a fiber-optic cable connected between the facility to the remote location, signal transmission means at the remote location for transmitting signals to the fiber-optic cable, a distribution hub for receiving signals from the other end of the cable and at least one secondary hub located at the facility in communication with the distribution hub. Communication between the facility and the remote location is effected using a Local Area Network. Preferably Ethernet signalling is used throughout the network.

Abstract: A method of monitoring cathodic protection of an item located at an underwater facility having an item requiring cathodic protection, and the facility are provided. The facility can include a processing device. The steps can include providing a pair of first and second electrodes, the first electrode being electrically connected to the item and the second electrode being in contact with water proximate the item, measuring the potential between the first and second electrodes, producing an electrical signal indicative of the cathodic protection level, converting the signal into a communications format compatible with the processing device and passing it to the processing device, and transmitting the converted signal from the processing device to a surface location.

Abstract: A method of monitoring a solenoid (1) of a directional control valve (DCV) associated with a subsea control module (6) in a subsea hydrocarbon production system is disclosed. A voltage is applied across a coil of the solenoid, for moving the armature (4) thereof, and a current through the coil is sensed to produce an indication of if and when the armature is moved.

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.

Abstract: A method for providing an umbilical connection for a well installation, the well installation being located at the bed or floor of a body of water, comprises the steps of providing an umbilical with first and second ends and prior to operative deployment of the umbilical, locating the umbilical such that at least a portion of the umbilical is substantially statically retained within the body of water. Additionally, an umbilical deployment system for a well installation located at the bed or floor of a body of water, comprises an umbilical, wherein, prior to operative deployment of the umbilical, at least a portion of the umbilical is substantially statically retained within the body of water.

Abstract: A protection apparatus detects and reduces overpressure in a fluid pipeline. First and second pipeline valves are connected in series along the pipeline and are independently switchable between open and closed positions. A pressure transducer determines the fluid pressure in the pipeline at a point intermediate the first and second pipeline valves. A bypass line has a first end connected to the pipeline between the input end and the first pipeline valve and a second end connected to the pipeline between the first and second pipeline valves. A bypass valve is connected along the bypass line. A vent line is connected to the bypass line between the bypass valve and the second end of the bypass line. A vent valve is connected along the vent line.

Abstract: A stabplate connection is provided by: providing a first part (1) comprising a stabplate and carried by an underwater structure; providing a second part (2) comprising a stabplate carried by tooling (4); engaging the tooling with said first part; using the tooling to bring the parts together so the stabplates mate with each other; using the tooling to lock the first and second parts together by engaging a portion (6) carried by the first part with a portion (10) carried by the second part; disengaging the tooling from the first part; and removing the tooling from the stabplate connection.

Abstract: A method for monitoring the condition of apparatus located at an underwater facility that includes sensing at least one parameter associated with the apparatus, providing a model of expected behaviour of said at least one parameter, comparing said sensed parameter with said model, and assessing the condition of the apparatus based upon said comparison.

Abstract: An AC power switching module comprising: AC current input and output means; switching means located between said input and output means for selectively blocking or passing said AC current; a switch controller arranged to provide an output signal to the switching means to control the state of the switching means; a primary control for setting the output of the switch controller; and a secondary control for setting the output of the switch controller, wherein said secondary control comprises a current-dependent circuit dependent on the AC current.

Abstract: A method of enabling communication between components of a hydrocarbon extraction plant, the plant having an underwater hydrocarbon extraction installation including at least one hydrocarbon extraction well with an associated tree, comprises providing a plurality of RF communication means at respective components of the installation.

Abstract: An underwater termination assembly for use with a subsea system such as a well tree, comprises a construction having first and second limbs substantially at a right-angle to each other, which construction may be lowered having an umbilical connected to one of the limbs so that said one of the limbs sits on the bed of a body of water.

Abstract: A module for use as a subsea electronic module of a subsea well, comprises an input (7) for receiving signals from a sensor arrangement which senses at least one parameter of a well, the module including a plurality of separate, different electronic circuits (9), each of which is selectable to be in communication with said input and each of which is adapted to co-operate with a respective, different form of such a sensor arrangement.

Abstract: An underwater stabplate connection is provided by lowering a counterbalanced first part of the connection in a horizontal disposition by a lift line, the first part being attached to an umbilical. The first part of the connection mates with a second part of the connection, the second part being attached to an underwater structure such as a well tree.

Abstract: A subsea well control system comprises: a well tree (6 or 7) having a subsea control module (10 or 11); and a power and communications distribution module (5) for communication with the subsea control module via a communication link (8 or 9) between the subsea control module and the distribution module. The link comprises a 4-wire dual twisted copper pair as part of an RS422-based interface.

Abstract: A communication system transmits data in a control system for an underwater fluid well. A communications link is located between first and second facilities of the well. A data transmitter for transmitting data from one of the facilities to the other via the communications link has both a relatively high speed modem and a relatively low speed modem.

Abstract: A method of mounting a subsea control module (1) on a mounting plate (10) of an underwater tree of a subsea hydrocarbon well comprises lowering the module to the plate and attaching the module to the plate with an adapter (6) between it and the plate and with portions of the module being coupled with portions of the mounting plate.