The WHCP consists of a hydraulic power unit (HPU) tubing and fitting, instrument valves as well as electrical devices for control mostly used in oil & gas engineering company. HPU provides hydraulic power that allows you to close and open SSV, which includes MSSV, WSSV, and SSSV. The WHCP can also be known by the names SDP, ESD, or HSSS. These are fail-safe shutdown systems that have pneumatic, hydraulic, and electric elements; WHCP can also be integrated with PLC, RTU, and SCADA.
WHCP for a gas well or an oil well that is employed to control well for shutdown. Tubing pressure reading parameters, casing pressure reading parameters, temperature well parameters. To open or close a WV, as well as DHSV, pressure switch -Low/Hi Hi, The Fusible plug, TG, PG, FG.
The last component of the system shut down
DHSV, Down Hole safety valve, and MV master valve SSV. Surface security valve, Choke valve, operated manually, SDV located in the flow line of the well and outside which is the head of the well (X-mas tree). Valves are part of the valve that will receive signals to be closed or opened by the Wellhead Control Panels. A relief valve shall be installed in every hydraulic circuit to stop the development of high pressure. Regulators are used to supplying controlled pressure to downstream oil headers that are utilized to regulate the supply header. e.g., If a valve needs more operating pressure, this circuit will be equipped with an individual regulation valve and one for pressure relief.
The Issues that Usually arise within the WHCP are leaking and sticking of 3-way valve components as well as the popping sound of PSV. A wrong MOC selection for components included in pneumatic ckts, O rings, etc., might be affected by hydrocarbon service.
Different types of WHCP
single WHCP
A single wellhead control panels are used to handle one well’s surface control SCSSV, Master SSV, and Wing SSV. SSVs can be shut off either manually or automatically by WHCP to respond to any kind of emergency situation. A single WHCP is classified as a system founded on the controlled source: Manual control system, electrical control system, pneumatic control system Solar power-driven control system.
Multi-Wellhead Control Panel
Each control module is swapped out without interruption of other good operations. Common modules include a reservoir for oil, a Pneumatic, hydraulic pump, and a standby manual pump. The main purpose is as follows: Remote RTU shut down; Fire plugs that are fusible, low pressure/high-Pressure sensing, manual control on the panel. Each controller is set to be a part of one well only. So if there are five wells in a wellhead platform, there will be a base cabinet and 5 Wellhead Control Modules needed. In general, SCSSV operates at high pressure, and SSV will be operating at a medium pressure rating. Therefore, there are two hydraulic headers on WHCP, and each has its separate hydraulic pump. The hydraulic pump is powered by electric or pneumatic. It all is dependent on the criticality of operation and zone.
Working Of WHCP
Every hydraulic pump suction system is equipped with a strainer that will remove the hydraulic fluid of any particles to ensure that the fluid going into SCSSV and SSV is clear. To make the hydraulic demands coming from SCSSV or SSV feasible. The downstream part of the hydraulic pumps (hydraulic head) is fitted with an accumulator. The sizing of the accumulator is made so that it permits two cycles of closing and opening of all valves for wellheads without the need for pumping. Accumulators are pre-charged types. Based on the isothermal compression and expansion of the nitrogen pre-charge gas, the effective gas volume required is calculated.
Accumulators are established in WHCP hydraulic circuits to deliver pressure in case oil pressure is not there. It helps the hydraulic pump to supply the hydraulic demand quickly. This arrangement generally is known as a hydraulic power unit or a Hydraulic power unit. After the hydraulic fluid has accumulated at the hydraulic head (both medium and high pressure), then it is now ready to provide each wellhead control module.
The line that connects the hydraulic header to the wellhead control module is referred to as the hydraulic supply line. In this module, the sequence and the algorithm to control SCSSV and SCSSV, along with the SSV, are created. The ESD signal is mainly sent into this unit. If it is required for it to gain access to SCSSV and the SCSSV and SSV and SSV. It will supply medium or high tension hydraulic fluids to SCSSV along with the SSV. In the event of a need to shut the valve, the supply of hydraulic fluid will stop, and the hydraulic fluid is routed to a return line that is connected to a three-way valve selector. The hydraulic return line attaches to the reservoir.
WHCP is a hydraulic system
Based on this rationale, we can decide that the WHCP is a hydraulic system that makes usage of an electric power pack as well as the wellhead control module in order to execute its job. The material used in WHCP must be SS316/L and should be equipped with an IP 65 protection class and a canopy or sunshade for outside installation. The WHCP panel is installed on the ground near the pad for the well and doesn’t contain a controller component. PCLC and RTU panels can be positioned in a secure field as well as in a controlled setting. Typically, Remote I/O panels are placed in the field to serve as the operation interfaces that are connected to oil wells.
Instrumentation interface pressure
Local pressure gauges and transmitters must be installed on the Hydraulic headers to provide local monitoring and for the status indicative of valves. Level transmitters and LG are needed to check the reservoir level. Solenoids are used to supply headers for valves. Once solenoids are energized, hydraulic oil will pass through the solenoid and goes to valve actuators. Push buttons, selector switches for the Christmas Tree valves local, test, remote operation SSSVs. Open/Close status indication lamps for the SSVs, SSSVs, UMVs, WVs, etc. Junction boxes for interconnection between WHCP and PLC/Control system Pressure, Level, solenoids, or Control valve, start, stop of hydraulic pumps, status indication, local operation interfaces, etc.
Conclusion
In short, WHCP was designed in order to supply the required hydraulic pressure needed to keep the entire valves. It including Wing Valves (WV) as well as Master Valves (LMV and UMV) and sub-surface Safety Valves (SSSV) with their valves open in normal conditions, and close the valves when there are abnormal or circumstances of the trip.
