A system for determining a fault in a subsea blowout preventer (BOP) stack includes a first sensor and a second sensor adapted to measure one or more properties of a subsea operation. The system further includes a first power supply adapted to provide operational power to the first sensor and a second power supply adapted to provide operational power to the second sensor. The system also includes a first power failure indicator and isolator (PFII) associated with the first sensor and the first power supply, the first PFII measuring a first pair of waveforms to identify a first fault and a second PFII associated with the second sensor and the second power supply, the second PFII measuring a second pair of waveforms to identify a second fault.

A valve for preventing hydraulic shock and water hammer in downstream equipment, the valve including a valve body with an internal oil dampening chamber, an orifice arranged within the oil dampening chamber, a flow dampener positioned between the valve inlet and the orifice, and a spring between the valve body and the orifice. The valve is pressure compensated based on the ambient fluid pressure.

A control system for controlling disconnection of riser system that extends between a vessel and a subsea location that comprises a wellbore, the riser system configured to receive a string in use, the control system being configured to disconnect the riser system according to a sequence of operations, the sequence of operations comprising disconnecting the riser system prior to or simultaneous with cutting the string and sealing the well bore.

A system for operating a blowout preventer (BOP) includes a front piston positioned at least partially in a front chamber. The front chamber includes a front volume on a front side of the front piston, and a back volume on a back side of the front piston. The system also includes a back piston connected to the front piston. The back piston is positioned at least partially in a back chamber. The back chamber includes a front volume on a front side of the back piston, and a back volume on a back side of the back piston. The system also includes a first valve configured to permit fluid flow into the front chamber during a free closing stroke of the BOP. The system also includes a second valve configured to permit fluid flow between the front and back volumes of the back chamber during the free closing stroke.

An underwater robotic system includes a frame adapted to be deployed in a body of water and having guide rails and at least one movable rail movably coupled to the guide rails. An actuator module is movably coupled to the at least one movable rail. A control panel disposed proximate the frame and has a plurality of controls thereon. The plurality of controls is operable by an actuator on the actuator module. A position of each of the plurality of controls is known such that motion of the actuator module and the at least one movable rail is remotely controllable to actuate any chosen one of the plurality of controls.

Methods of controlling surface systems described herein include acquiring data during operation of a surface system that handles fluid using sub-systems; generating a parameter value for one of the sub-systems using at least a portion of the data and a model that models the sub-system using historical data that include operational adjustment data for operational adjustments responsive to conditions; and automatically controlling the one of the sub-systems using the parameter value.

The invention relates to a self-propelled valve actuator on a rail transport system for manifolds and Christmas trees. The valve actuator is moveable along a transport rail and may operate several valves. The valve actuator is driven by a gearwheel motor. The invention also relates to a rotatable valve head having diametrical slots with which the valve actuator may interact.

An accumulator system that includes a housing. The housing defines a function chamber and a balance chamber. A piston moves axially within the housing. The piston separates the function chamber from the balance chamber. An electric actuator couples to and drives the piston within the housing to compress and drive a first fluid out of the function chamber.

A well production system comprises a safety instrumented system (SIS) having one or more logic solvers; one or more pressure transmitters disposed along a flowpath and communicatively coupled to the one or more logic solvers; one or more valves disposed along the flowpath and communicatively coupled to the SIS, wherein the SIS is configured to selectively actuate the one or more valves based on feedback from the one or more pressure transmitters; and a spare pressure transmitter disposed along the flowpath, wherein the spare pressure transmitter is configured to be selectively coupled to the one or more logic solvers.

Systems and methods for initiating an emergency disconnect sequence (EDS) are provided. In an aspect, a disconnection system is provided and configured to initiate the EDS, and includes a controller including a processor and a memory operably coupled to the processor. The controller receives, from a set of motion reference units (MRU(s)) operably coupled to a flexible joint, position data generated by the set of motion references units and associated with the joint when the joint is operably coupled to and disposed between a drilling riser and a lower marine riser package (LMRP). The controller determines, based on the position data, an angular offset of the joint. The controller sends, to a subsea control pod disposed at or adjacent to the LMRP, a trigger signal in response to determining that the angular offset exceeds a predetermined threshold, such that the subsea control pod initiates the EDS.