Bop Controls
BOP controls equipment shall shall meet the area classification requirements for the area in which it is installed.
Control Fluid
Control fluid(gases and liquids) shall be selected and maintained to meet minimum BOP equipment manufacturers’ and fluid supplier’s properties, and the equipment owner’s requirements.
The control fluid shall be maintained to prevent freezing when required.
Control fluid reservoir: Control fluid reservoirs shall be cleaned, flushed of contaminants, and have vents inspected before fluid is introduced per the equipment owner’s maintenance system.
Pump system: A minimum of two pump systems shall be required, a pump system may consist of one or more pumps.
The two required pump systems shall have independent power sources.
Note:
Additional pump systems do not require independent power sources.
These pump systems shall be connected such shat the loss of any one power source does not impair the operation of all the pump systems. At least one pump system shall be available while the BOP is in operation.
Hydraulic control unit location: The hydraulic control unit should be outside the drill floor substructure.
Accumulator systems: A nonoxidizing insert gas, such as nitrogen or helium, shall be used for pre-charging accumulators.
Neither atmospheric air nor oxygen shall be used.
The gas used shall be in accordance with the accumulator design.
Subsea accumulators shall be discharged subsea prior to recovering the BOP stack to the surface or include a relief device to prevent over-pressurization of the circuit.
Main accumulator system: the main accumulator system consists of the surface accumulator system and any stack-mounted accumulators that are part of the main control system(not dedicated accumulators for emergency or secondary systems).
Accumulator Pre-charge: the pre-charge pressure for each surface accumulator bottle shall be measured and adjusted in accordance with equipment owner’s maintenance system.
The pre-charge pressure on each stack-mounted accumulator bottle shall be measured prior to BOP stack deployment and adjusted in accordance with the API 16D method specified in the manufacturer’s sizing documentation.
The manufacturer-supplied control system surface base pressure, adjusted for water depth and operating temperature, shall be used as required.
Documentation of the accumulator pre-charge measurement and adjustment shall be retained and retrievable until the end of the well.
The calculated pre-charge pressures, along with documentation supporting nonoptimal pre-charge pressure(if used), shall be filed with the well-specific data package.
