== BOP control device function ==
The BOP control device is the device that switches the BOP and the hydraulic valve on and off.
It is an important equipment for controlling wellhead BOP group, hydrodynamic throttling and kill valve, and an indispensable device for preventing blowout in drilling, completion and workover operations.
The function of the control device is to prepare and store sufficient pressure oil in advance and control the flow direction of the pressure oil.
so that the BOP and hydraulic valve can be switching on and off quickly.
When the hydraulic oil is consuming and the oil pressure is reducing to a certain extent, the control device will automatically replenish the oil storage.
so that the hydraulic oil is always kept within the high pressure range.
Model representation Method of Surface BOP Control System (Taking FKQ640-6 as an example)
== Main component composition ==
The surface BOP control device mainly consists of the following components:
- 1. Remote console
- 2. Driller console, Auxiliary driller console
- 3. Air lines
- 4. Hydraulic pipelines (including soft pipelines or pipe racks)
1. Remote console
The remote console is composing of oil tank, pump group, accumulator group, manifold, various valves, instrument and electric control box, etc.
The main function of the remote console is to generate high pressure control fluid by the pump group and store it in the accumulator group.
When the BOP needs to be opening and closing, the high pressure control fluid.
from the accumulator is distributing to each control object (the BOP) through the three-way four-way rotary valve in the manifold.
2. Driller console
The driller’s console is usually located on the drillfloor, allowing the driller to easily control the BOP remotely.
3. Air lines
The air line connects the air path between the remote console and the driller’s console. The cable consists of a sheath and a number of tubes with connecting flanges at both ends.
and is connecting to the remote console and the driller’s console, respectively.
4. Hydraulic lines
Typically, the remote console is 40m away from the wellhead BOP stack, which is connecting by a set of hydraulic lines. The connection modes are hard pipeline connection and soft pipeline connection.
Hard pipelines include pipe racks, movable pipelines, etc. The use of hard pipeline connection, has the advantages of safety and reliability, the disadvantage is that the installation layout is not convenient. Flexible pipe connection has the advantages of simplicity and convenience, but its safety should be paid attention to in use.
The working process of the gas-controlled liquid control device can be dividing into the preparation of hydraulic energy; Regulation of storage and replenishment pressure oil and control of its flow direction; Pneumatic remote control three parts.
1. Preparation, storage and supplement of hydraulic energy
As shown in the figure, the hydraulic oil in the tank enters the electric pump or pneumatic pump through the oil valve and filter. The electric pump or pneumatic pump boosts the hydraulic oil and feeds it into the accumulator group for storage. The accumulator group consists of several cylinders in which 7MPa nitrogen is pre-flushing. When the oil pressure in the accumulator cylinder rises to 21MPa, the electric pump or the pneumatic pump stops running. When the oil pressure in the cylinder drops too much, the electric or pneumatic pump automatically starts to replenish the pressure oil in the cylinder. In this way, the accumulator cylinder will always maintain the required pressure oil.
The air supply line of the pneumatic pump is equipping with a water filter, an oil mist, a pressure regulator and a bypass stop valve. Usually, the bypass stop valve is closing. Only when the pressure of oil above 21MPa needs to be preparing.
the bypass stop valve is opening and the pneumatic pump is using to produce high pressure liquid energy.
2. Regulation of pressure oil and control of its flow direction
As shown in the figure, the pressure oil in the accumulator cylinder is dividing into two ways after entering the control manifold. One way, the oil pressure is reducing to 10.5MPa through the gas manual pressure regulating valve.
and then it is fed to the liquid rotary valve (three-position four-way liquid rotary valve) that controls the annular BOP. In the other way, the oil pressure is lowering to 10.5MPa through the manual pressure regulating valve, and then it is transmitting to the manifold of the liquid rotary valve (three-position four-way liquid rotary valve) that controls the sluice BOP and hydraulic valve. By manipulating the handle of the rotary valve, the corresponding BOP can be switching on and off.
When the 10.5MPa pressure oil cannot push the ram BOP to shut in the well.
the bypass valve handle can be manipulating to direct the high pressure oil from the accumulator into the manifold and use the high pressure oil to push the ram. In a unit equipped with a nitrogen tank set, high-pressure nitrogen can be using to drive the remaining oil in the line to perform an emergency BOP shut-in operation when the accumulator’s oil pressure is severely insufficient. The manifold is fitted with a pressure relief valve. Normally, the pressure relief valve is in closed condition. Opening the pressure relief valve can discharge the pressure oil in the accumulator back to the tank.
3. Pneumatic remote control
The above two parts of the hydraulic control process belong to the work overview of the remote control device. A remote control device is requiring to enable the driller to remotely switch the wellhead BOP on and off from the rig floor. The pneumatic remote control process is shown in the figure. The compressed air is transmitting to each air reversing valve (three-way reversing slide valve or rotary valve) through the water filter and oil mist after the air source main valve (two-position three-way reversing valve). The air reversing valve is responsible for controlling the action of the two cylinders on the remote control device, thus controlling the corresponding reversing valve handle on the remote control device and indirectly controlling the switching action of the wellhead BOP.
The reversing valve that controls the annular BOP switch on the remote control device is equipping with a gas manual pressure reducing valve on the oil supply line. The gas manual pressure reducing valve is regulating by the remote control device or the pressure regulating valve on the remote control device. The control route is determining by the three-way distribution valve (two-position three-way reversing valve). Normally, the gas manual pressure reducing valve should be controlling by the pressure regulating valve on the remote control device.
There are four pressure gauges on the remote control unit, three of which show oil pressure.
Three pressure transmitters on the remote control device convert the accumulator pressure value of the remote control device, the oil supply value of the annular BOP (annular pressure), and the oil supply value of the gate BOP (manifold pressure) into the corresponding low pressure value. The converted air pressure is then transmitting to the pressure gauge on the remote rig floor to display the corresponding oil pressure. The other is the air source pressure gauge. The preparation of hydraulic energy, the regulation of pressure oil and the control of its flow direction are all completed on the remote control device. The components and pipelines of the typical remote control device are shown in the figure.
== Install ==
- 1) When hoisting the remote console with the protection room, four steel ropes must be installed on the four legs of the base for lifting. Please pay attention to the stability of lifting. When hoisting the driller’s console or pipe rack, the wire rope should be hoisting through or hooked to the ring.
- 2) The remote console shall be installed at an appropriate location 30 meters away from the wellhead (refer to relevant standards and specifications), and the driller’s console shall be locating on the drillfloor where the driller can operate.
- 3) Tubing connection
It is recommending to start from the BOP body and connect the pipelines one by one. In this way, the pipelines can be neatly arranging and easily adjusting to avoid rework. In addition, full attention must be paid to the fact that all oil and gas lines should be blown clean with compressing air before installation. Above the rear channel steel of the base of the remote console, the characters “O” or “C” are welding corresponding to each oil pipe. “O” means “on” (0PEN) and “C” means “off” (Cl0SE).
Therefore, when connecting the pipeline, it is necessary to connect the pipeline according to the full seal, half seal, ring, blowout and other corresponding connections as shown in the rotary valve sign on the remote console. It is also necessary to pay attention to that the pipeline marked “O” or “C” must be consistent with the “open” or “close” oil port on the BOP body.
Connecting the wrong control object, or connecting the wrong switch direction, will result in the wrong action, must be carefully identifing before connecting the pipe. When connecting, pay attention to the pipe joint should not be blocked or leaked, and there should be no dirt in the pipeline, otherwise it will affect the reliable work of the system.
- 4) Connection of trachea
FKQ series liquid control device, need to connect the air source line and air line. When connecting the air cable, pay attention to the direction of the connecting flange, place the sealing gasket between the flange faces, and tighten the bolts evenly.
The remote console air source is connected using a 25mm bore hose and the driller’s console air source is connected using a 13mm bore hose. The joint between the hose and the joint must be tightened with a throat clamp to prevent loose. The hose should be free from aging, cracking and other defects, so as not to burst during use.
Note: When connecting the gas pipeline, ensure that there is no dead bend in the pipeline and the connection of the pipeline joint is reliable.
so as to avoid the pipeline burst, the joint slip and other faults. When connecting the flanges at both ends of the air cable.
if the sealing ring is not properly padding or the connecting bolts are not evenly tightening, the gas between the pipes will be causing, resulting in misoperation.
5) Power connection
The power supply is 380V and 50HZ AC.
The ground terminal of the electric control box.
should be grounding reliably according to the relevant electrical regulations to avoid personal accidents.
• Before wiring, turn the main command switch of the electric control box.
on the remote console to the “stop” position to prevent accidents caused by the motor starting immediately after power-on.
• Note: Before the system is connecting to the power supply, make sure that the main switch on the electric cabinet is in the “stop” position to avoid accidents.
Before powering on, make sure the control device is reliably grounding.
• After the equipment is installing, carefully check whether all the connection pipes are wrong and whether all kinds of live joints and joints are tightening before the test run.
== Test run ==
The preparatory work before the test run shall be carriing out according to the following procedures:
- 1. Pre-charge or check the nitrogen pressure of the accumulator one by one. The pressure should be 7±0.7MPa and 1000±100psi.
- 2. Fill up the tank.
- It can be added by the refueling port at the top of the tank, or it can be opened by the suction pipe of the electric oil pump. The amount of fuel should be controlling at the top of the tank marked on the oil mark.§
- When the ambient temperature is above 0℃, use YA-N32 ordinary hydraulic oil or suitable substitute oil.§
- When the ambient temperature is below 0℃, use YC-N32 low temperature hydraulic oil or suitable substitute oil.
- 3. Lubricate the moving parts.
- 4. Open the accumulator isolation valve, open the unloading valve on the control manifold.
- turn the handle of each three-way four-way rotary valve to the middle position, and put the bypass valve in the “Off” position.
- 5. Turn the master switch to the “manual” position, and turn the master switch to the “stop” position after the motor starts.
- When the motor stops slowly, observe whether its turn is consistent with the direction indicating by the arrow above the chain shield.
- If it is inconsistent, change the phase of the power cord.