The Wellhead forms the highest portion of the well that leads towards the reservoir. The reservoir’s oil comes out of the Well hole and is then pumped out through the casing. The flow of gas or oil out of the well must be enough to allow it to be commercially viable. Then, only the wellhead is placed on highest point of the well. It is comprised of valves and other equipment that regulate the flow and pressure at the wellhead. This equipment and its management is the most important in oil fields. They prevent dangerous conditions in oil & gas engineering company plants. The danger is resulted from the flow of flammable material from the well as well as the pressure that builds up inside the well. This means that the flow through the wellhead needs to be managed and created fail-safe. This is why Wellhead Control Panels (WHCP) are used.
This wellhead can also be referred to for its Christmas tree (because because of its shape). The Christmas tree comprises subsurface controlled safety valves (SCSSV), Surface Safety Valves (SSV) and other safety valves for the wellhead (Choke, ESD, HIPPS). These valves can be used to shut off the well when required. On the top in the structure the pressure gauge will show the level of pressure inside the tubing.
The actions that must take place within the wellhead are controlled by the three valves using the aid of gauges and choke.
What is a WHCP?
The function the purpose of WHCP is to keep track of the Subsurface Controlled Safety Valves (SCSSV), Surface Safety Valves (SSV) and other safety valves for wellheads (Choke, ESD, HIPPS) for the security for the water. A WHCP will reduce the chance of damage or injury to people as well as the environment or equipment. The wellhead control systems are made in a way to ensure that they are “fail-safe.” Wellheads is operated and controlled through PLC or SCADA systems.
The WHCP receives input signals from various gauges like temperature, pressure and flow gauges located in the wellhead. Additionally, the primary inputs come from emergency shutdown systems (ESD) and emergency pushbuttons, as well as fusible plugs. The output is produced through the reading of these signals, which are usually a signal to shut off the valves at the wellhead in order to ensure the plant’s security.
The WHCP utilizes both pneumatic and hydraulic components. SCSSVs are typically located on land wells which are operated with hydraulic power. In this scenario the WHCP should include the hydraulic reservoir as well as the pump system that maintains the pressure of subsurface valves throughout normal operation. However, WHCP uses pneumatics for monitoring and controlling surface security valves (SSV).
Therefore, WHCP is a collection of control systems that allow for the control of execution of plans as well as emergency shutdowns. For land-based wells, a distinct controlled wellhead system utilized for each well operating under pressures of high. The control systems for wellheads on offshore platforms are organized into at least one panel. The logic controlling each well is distinct from other wells in order to create or eliminate new wells as necessary.
Principle
There are several kinds of WHCP classified according to the place of operation. They include electric control panels as well as solar-powered, manual and pneumatic controlled panels. The choice of the type will be determined based on the requirements of the particular application. The control panel is available in two different ways: one wellhead control panel and multi-wellhead control panel. We will be discussing the different types of control panels in the upcoming sections.
WHCP manages the gas and oil wells. WHCP does this through the control of valves at the wellhead. They comprise SCSSV (Surface Controlled Sub-surface Safety Valves) and SSV (Surface Safety Valves), comprising master Valves (MV) as well as the Wing Valves (WV). The sequence of functioning between SCSSV and SSV assists in an Emergency Shutdown (ESD) process.
In addition to the essential parts of the control panel WHCP is comprised of a hydro reservoir strainer and hydraulic pump the accumulator, the wellhead control module, as well as hydraulic lines that are used to supply back to control module for the wellhead. The hydraulic fluid in the reservoir is used to operate the wellhead. The size of the reservoir can be measured by the quantity of fluid required to operate the valve and how far the reservoir is from the well.
SCSSV and SSV SCSSV and SSV work at a hydraulic pressure. SCSSV with high pressure SSV at high pressure, as well as SSV in medium-pressure. The hydraulic power unit, also known as an hydraulic power system is used to meet the requirements for pressure and consists of the reservoir, hydraulic pumps along with an accumulator. The reservoir holds hydraulic fluid and there are two pumps and hydraulic heads within each wellhead. The pumps will then include a strainer for removing the hydraulic fluid of any particles so that the hydraulic fluid that is going through SCSSV as well as SSV is clear. Based on the operating environment the hydraulics could be electrically driven or pneumatically driven. A accumulator is used in the downstream area of the pump to reach the pressure desired in the case of SCSSV as well as SSV.
The hydraulic fluid accumulated at the head of the well is delivered via lines for hydraulic supply to the control module for the wellhead whenever it is needed. The sequence and the logic controlling the SCSSV and SSV are set up by the wellhead control module. To regulate the flow of fluid or to execute the ESD procedure signal from the control panel get to the control module for the wellhead. Once it has received the signal for control the control module for the wellhead opens SCSSV and SCSSV as well as the SSV by sending high and medium pressure and medium pressure, respectively. The hydraulic fluid is then returned to the line hydraulically by activating a three-way valve that will shut the valves.
It is the way the control panel works to regulate the flow of water through the wellhead and to initiate an emergency shutdown procedures.
FUNCTIONS OF WHCP’S PRIMARY FUNCTIONS
- Shut off the well in case of a hazardous situation
- Controls the crucial security parameters
- Sequential start-up and down process of the wellhead
- Monitor and control closely SCSSV.
- WHCP utilizes distinct Hydraulic power units (HPUs) that allow hydraulic reservoirs, pumps, accumulators and more.
- Special pushbuttons are utilized in the panel to shut off the master valve, wing valve valve and SCSSV.
WHCP Participants
WHCP is situated near the wellhead. However, the control system, PLC or SCADA, is installed in a secure zone. The logic signals that are sent to the WHCP originate coming from Control System (PLC or SCADA). The WHCP close to the wellhead will perform the control action in a direct manner. The most important component of the WHCP comprises its Hydraulic Power Unit (HPU) which is comprised of an hydraulic pump, reservoir and an accumulator.
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