Abstract: A system for determining the location of a movable element within a container is provided in which a linear variable differential transformer (“LVDT”) is formed with the container and the movable element therein. The LVDT includes a coil assembly including a primary or excitation winding, a secondary or output winding, and a movable element or core that is magnetically permeable. Measurement of an output signals allows for precise determination of the movable element location relative to the container. The system can be utilized to determine fluid volumes in accumulators used for controlling subsea equipment by monitoring the location of a movable element, e.g., a piston, within a hydraulic fluid accumulator.

Abstract: An apparatus for controlling hydraulically actuatable components of a blowout preventer stack assembly and a system for same. The apparatus comprises a blowout preventer stack including hydraulically actuatable components and a lower marine riser package coupled to the blowout preventer stack and including additional hydraulic components. The lower marine riser package includes a solenoid valve configured to control at least some of the components. The solenoid valve receives hydraulic fluid from a dedicated accumulator or accumulator bank configured to supply hydraulic fluid exclusively for use with the solenoid valve. A closed-loop hydraulic circuit is formed between the accumulator or accumulator bank and the solenoid valve.

Abstract: An apparatus for monitoring the condition of a seal, such as a seal in a blowout preventer or in another oilfield device, is provided. In one embodiment, the apparatus includes a blowout preventer including a seal and a blowout preventer seal-monitoring system that includes a sensor positioned within a body of the seal and a data analyzer. The data analyzer has a processor and is configured to monitor a condition of the seal through analysis of data received by the data analyzer from the sensor positioned within the body of the seal. Additional systems, devices, and methods are also disclosed.

Abstract: A subsea drilling system that includes a blowout preventer (BOP) stack with accumulators. The drilling system also includes an intensifier that is cyclable to communicate an increased pressure to the accumulators than that provided by surface equipment so as to charge the accumulators with the increased pressure. The subsea drilling system also includes a control system locatable subsea that operates the intensifier to pump fluid into the accumulators.

Abstract: A system for reducing pressure in a subsea operator. In one embodiment, a subsea system includes an operator and a deintensifier. The operator includes a housing and a piston. The piston is movably disposed within the operator housing and divides an inner volume of the operator housing into a closing chamber and a second chamber. The deintensifier is fluidically coupled to the operator. The deintensifier includes a housing and a piston. The piston includes a closing surface and an opening surface. The closing surface is fluidically coupled to the second chamber of the operator housing. The opening surface is fluidically coupled to ambient pressure. The area of the closing surface is greater than an area of the opening surface so as to increase the pressure differential between the closing chamber and the second chamber and assist in moving the operator piston to the closed position.

Abstract: An apparatus for controlling hydraulically actuatable components of a blowout preventer stack assembly and a system for same. The apparatus comprises a blowout preventer stack including hydraulically actuatable components and a lower marine riser package coupled to the blowout preventer stack and including additional hydraulic components. The lower marine riser package includes a solenoid valve configured to control at least some of the components. The solenoid valve receives hydraulic fluid from a dedicated accumulator or accumulator bank configured to supply hydraulic fluid exclusively for use with the solenoid valve. A closed-loop hydraulic circuit is formed between the accumulator or accumulator bank and the solenoid valve.

Abstract: A fluid control system may be included within a blowout preventer subsea control pod of a subsea drilling system. The fluid control system includes a primary fluid flow path including an inlet and an outlet, the inlet connectable to a fluid supply source, the outlet connectable to a component controllable by the fluid supply source, a surge relief valve connected within the primary fluid flow path between the inlet and the outlet, and a control valve connected within the primary fluid flow path between the surge relief valve and the outlet such that hydraulic pressure surges received within the primary fluid flow path are dampened, at least partially, by the surge relief valve before received by the control valve.

Abstract: An apparatus for monitoring the condition of a seal, such as a seal in a blowout preventer or in another oilfield device, is provided. In one embodiment, the apparatus includes a blowout preventer including a seal and a blowout preventer seal-monitoring system that includes a sensor positioned within a body of the seal and a data analyzer. The data analyzer has a processor and is configured to monitor a condition of the seal through analysis of data received by the data analyzer from the sensor positioned within the body of the seal. Additional systems, devices, and methods are also disclosed.

Abstract: A subsea drilling system that includes a blowout preventer (BOP) stack with accumulators. The drilling system also includes an intensifier that is cyclable to communicate an increased pressure to the accumulators than that provided by surface equipment so as to charge the accumulators with the increased pressure. The subsea drilling system also includes a control system locatable subsea that operates the intensifier to pump fluid into the accumulators.

Abstract: A blowout preventer system includes a blowout preventer stack having hydraulic components. The blowout preventer stack is coupled to a lower marine riser package that includes additional hydraulic components. The lower marine riser package includes control pods that enable redundant control of the hydraulic components of the blowout preventer stack and the additional hydraulic components of the lower marine riser package. These control pods include frames, valves, and stack stingers that facilitate connection of the control pods to hydraulic components of the blowout preventer stack, but do not include riser stingers that facilitate communication of control fluid to the additional hydraulic components of the lower marine riser package. The stack stingers extend through central apertures of bottom plates of the control pod frames and facilitate communication of control fluid from the valves to the hydraulic components of the blowout preventer stack. Additional systems, devices, and methods are also disclosed.

Abstract: A blowout preventer system includes a blowout preventer stack having hydraulic components. The blowout preventer stack is coupled to a lower marine riser package that includes additional hydraulic components. The lower marine riser package includes control pods that enable redundant control of the hydraulic components of the blowout preventer stack and the additional hydraulic components of the lower marine riser package. These control pods include frames, valves, and stack stingers that facilitate connection of the control pods to hydraulic components of the blowout preventer stack, but do not include riser stingers that facilitate communication of control fluid to the additional hydraulic components of the lower marine riser package. The stack stingers extend through central apertures of bottom plates of the control pod frames and facilitate communication of control fluid from the valves to the hydraulic components of the blowout preventer stack. Additional systems, devices, and methods are also disclosed.

Abstract: A system for determining the location of a movable element within a container is provided in which a linear variable differential transformer (“LVDT”) is formed with the container and the movable element therein. The LVDT includes a coil assembly including a primary or excitation winding, a secondary or output winding, and a movable element or core that is magnetically permeable. Measurement of an output signals allows for precise determination of the movable element location relative to the container. The system can be utilized to determine fluid volumes in accumulators used for controlling subsea equipment by monitoring the location of a movable element, e.g., a piston, within a hydraulic fluid accumulator.

Abstract: A blowout preventer system is provided. In one embodiment, such a system includes a blowout preventer stack including hydraulic components. The blowout preventer stack is coupled to a lower marine riser package that includes additional hydraulic components. The lower marine riser package further includes a pair of control pods that enables redundant control of the hydraulic components of the blowout preventer stack and the additional hydraulic components of the lower marine riser package. Still further, the lower marine riser package also includes a third control pod that enables additional redundant control of the hydraulic components of the blowout preventer stack and the additional hydraulic components of the lower marine riser package. Additional systems, devices, and methods are also disclosed.

Abstract: A system for reducing pressure in a subsea operator. In one embodiment, a subsea system includes an operator and a deintensifier. The operator includes a housing and a piston. The piston is movably disposed within the operator housing and divides an inner volume of the operator housing into a closing chamber and a second chamber. The deintensifier is fluidically coupled to the operator. The deintensifier includes a housing and a piston. The piston includes a closing surface and an opening surface. The closing surface is fluidically coupled to the second chamber of the operator housing. The opening surface is fluidically coupled to ambient pressure. The area of the closing surface is greater than an area of the opening surface so as to increase the pressure differential between the closing chamber and the second chamber and assist in moving the operator piston to the closed position.

Abstract: A system for reducing pressure in a subsea operator. In one embodiment, a subsea system includes an operator and a deintensifier. The operator includes a housing and a piston. The piston is movably disposed within the operator housing and divides an inner volume of the operator housing into a closing chamber and a second chamber. The deintensifier is fluidically coupled to the operator. The deintensifier includes a housing and a piston. The piston includes a closing surface and an opening surface. The closing surface is fluidically coupled to the second chamber of the operator housing. The opening surface is fluidically coupled to ambient pressure. The area of the closing surface is greater than an area of the opening surface so as to increase the pressure differential between the closing chamber and the second chamber and assist in moving the operator piston to the closed position.

Abstract: A blowout preventer system is provided. In one embodiment, such a system includes a blowout preventer stack including hydraulic components. The blowout preventer stack is coupled to a lower marine riser package that includes additional hydraulic components. The lower marine riser package further includes a pair of control pods that enables redundant control of the hydraulic components of the blowout preventer stack and the additional hydraulic components of the lower marine riser package. Still further, the lower marine riser package also includes a third control pod that enables additional redundant control of the hydraulic components of the blowout preventer stack and the additional hydraulic components of the lower marine riser package. Additional systems, devices, and methods are also disclosed.

Abstract: A fluid control system may be included within a blowout preventer subsea control pod of a subsea drilling system. The fluid control system includes a primary fluid flow path including an inlet and an outlet, the inlet connectable to a fluid supply source, the outlet connectable to a component controllable by the fluid supply source, a surge relief valve connected within the primary fluid flow path between the inlet and the outlet, and a control valve connected within the primary fluid flow path between the surge relief valve and the outlet such that hydraulic pressure surges received within the primary fluid flow path are dampened, at least partially, by the surge relief valve before received by the control valve.

Abstract: There is disclosed a system for controlling the operation of a ram of a subsea blowout preventer connected to a piston shiftable between alternate positions within a cylinder. The system includes valve apparatus for so shifting the piston which includes an outlet connected to the cylinder, a first passageway through which hydraulic fluid may be supplied to the outlet, a second passageway through which hydraulic fluid may be vented from the outlet, and a valve member movable between positions alternately connecting the outlet with the first and second passageways, respectively, so as to selectively supply hydraulic fluid to or vent hydraulic fluid from the cylinder.