API Spec 16D-2004 pdf free download

API Spec 16D-2004 pdf free download.Specification for Control Systems for Drilling Well Control Equipment and Control Systems for Diverter Equipment.
1 Scope 1.1 GENERAL These specifications establish design standards for systems, that are used to control blowout preventers (BOPs) and associated valves that control well pressure during drilling operations. The design standards applicable to subsystems and components do not include material selection and manufacturing process details but may serve as an aid to purchasing. Although diverters are not considered well control devices, their controls are often incorporated as part of the BOP control system. Thus, control systems for diverter equipment are included herein. Control systems for drilling well control equipment typically employ stored energy in the form of pressurized hydraulic fluid (power fluid) to operate (open and close) the BOP stack components. Each operation of a BOP or other well component is referred to as a control function. The control system equipment and circuitry vary generally in accor- dance with the application and environment. The specifications provided herein describe the following control system categories: a. Control systems for surface mounted BOP stacks. These systems are typically simple return-to-reservoir hydraulic control systems consisting of a reservoir for storing hydraulic fluid, pump equipment for pressurizing the hydraulic fluid, accumulator banks for storing power fluid and manifolding, piping and control valves for transmission of control fluid to the BOP stack functions. b. Control systems for subsea BOP stacks (common elements). Remote control of a seafloor BOP stack requires specialized equipment. Some of the control system elements are common to virtually all subsea control systems, regardless of the means used for function signal transmission. c. Discrete hydraulic control systems for subsea BOP stacks. In addition to the equipment required for surface-mounted BOP stacks, discrete hydraulic subsea control systems use umbilical hose bundles for transmission of hydraulic pilot signals subsea.
3 Terms, Definitions, and Abbreviated Terms Graphic symbols for fluid power diagrams shall be in accordance with ANSI Y32.10 and/or ISO Standard 1219, latest editions. For the purposes of this specification, the following definitions apply: 3.1 accumulator: A pressure vessel charged with non-reactive or inert gas used to store hydraulic fluid under pressure for operation of blowout preventers. 3.2 accumulator bank: An assemblage of multiple accumulators sharing a common manifold. 3.3 accumulator precharge: An initial inert gas charge in an accumulator, which is further compressed when the hydraulic fluid is pumped into the accumulator, thereby storing potential energy. 3.4 acoustic control system: A subsea control system that uses coded acoustic signals for communications and is normally used as an emergency backup having control of a few selected critical functions. 3.5 air pump/air-powered pump: Air driven hydraulic piston pump. 3.6 annular BOP: A device with a generally toroidal shaped steel-reinforced elastomer packing element that is hydraulically operated to close and seal around any drill pipe size or to provide full closure of the wellbore.
3.7 arm: To enable the operation of a critical function or functions. 3.8 backup: An element or system that is intended to be used only in the event that the primary element or system is non-func- tional. 3.9 blind ram BOP: A BOP having rams which seal against each other to close the wellbore in the absence of any pipe. 3.10 block position: The center position of a three-position control valve. 3.11 blowout: An uncontrolled flow of pressurized wellbore fluids. 3.12 BOP (blowout preventer): A device that allows the well to be sealed to confine the well fluids in the wellbore. 3.13 BOP closing ratio (ram BOP): A dimensionless factor equal to the area of the piston operator divided by area of the ram shaft. 3.14 BOP control system: The system of pumps, valves, accumulators, fluid storage and mixing equipment, manifold, pip- ing, hoses, control panels and other items necessary to hydraulically operate the BOP equipment. 3.15 BOP stack: The assembly of well control equipment including BOPs, spools, valves, and nipples connected to the top of the casing head. 3.16 BOP stack maximum rated wellbore pressure: The pressure containment rating of the ram BOPs in a stack. Note: In the event that the rams are rated at different pressures, the BOP stack maximum rated wellbore pressure is considered equal to the low- est rated ram BOP pressure. In stacks that do not contain any ram BOP, the BOP stack maximum rated wellbore pressure is considered equal to the lowest rated BOP pressure.