CN104100238B - It penetrates and draws booster-type casing gas recovering device - Google Patents

Abstract

The invention provides an injection pressurized casing gas recovery device, which is used for recovering the casing gas in the wellhead of an oil field. The device includes: ejector, gas-liquid mixed pump, liquid inlet valve, liquid outlet valve, inlet valve, gas storage tank, gas pressure sensor, gas flow meter, electric valve, control unit, etc., and is made into a skid-mounted piece. The liquid inlet of the ejector is connected with the upstream of the oil well oil outlet pipeline, and the liquid outlet is connected with the inlet of the gas-liquid mixed transport pump. When working normally, both the liquid inlet valve and the liquid outlet valve are opened. When the pressure of the casing gas reaches a certain value, the gas pressure sensor sends a signal to the control unit, and the control unit sends an instruction to start the mixed pump and open the electric valve after a delay; The high-speed flowing liquid in the introducer attracts the casing gas, and after mixing, it enters the mixed transport pump for pressurization, and then enters the oil well outlet pipeline to realize the recovery of the casing gas and avoid the damage caused by burning or venting the casing gas. Energy waste and air pollution.

Description

Injection pressurized casing gas recovery device

technical field

The invention relates to an injection pressurized casing gas recovery device, which is used for recovering the casing gas produced in the process of oil recovery in an oil field.

Background technique

In oilfield crude oil extraction, as the pressure of reservoir fluid decreases, light components in crude oil, such as methane, ethane, propane, etc., will volatilize from the annular space between casing and tubing to form casing gas. A gas column with a certain pressure is formed, which forces the dynamic liquid level of the oil well to drop, so that the effective production pressure drop of the oil well is reduced, and the production capacity is reduced; a part of the gas enters the pump cavity with the liquid flow, occupies a certain space in the pump cavity, and affects the pump efficiency. An "air lock" occurs, making the oil well pump inoperable.

Due to the low output of oil well casing gas and the unstable pressure, there is no special gas pipeline to transport casing gas, and the casing gas cannot be recovered and utilized effectively. Zone combustion or directly exhaust the casing gas.

In order to solve this problem, there are currently three methods for recovering casing gas: one is to use the power of the pumping unit itself to drive the plunger to recover the casing gas, and pressurize it to enter the wellhead pipeline; this device has a complex structure, and It is only suitable for oil extraction by pumping unit, not for oil extraction by submersible pump. The other is to use an air compressor device to increase the pressure of the casing gas, separate the gas from the liquid, and treat the harmful gas before entering the gas storage tank; this method has large investment, high maintenance and management costs, and large power consumption, which is economical. The benefit is not obvious, so it has not been popularized and applied. The third method is: connect several casing gases together, hold them to a certain pressure, and connect them to the oil pipe through a one-way valve connector; since the pressure of the casing gas is generally lower than the pressure of the crude oil in the oil pipe, this The device rarely actually works.

Contents of the invention

The purpose of the present invention is to overcome the shortcomings of the existing methods, and provide an injection pressurized casing gas recovery device to realize efficient and convenient recovery of wellhead casing gas.

Injection pressurized casing gas recovery device, including injector, gas-liquid mixed pump, liquid inlet valve, liquid outlet valve, air inlet valve, gas storage tank, gas pressure sensor, gas flow meter, electric valve, control unit and an air intake hose, the above-mentioned devices are integrally made into a skid-mounted block, the injector includes a liquid inlet and a liquid outlet, and the liquid inlet is sequentially connected to an external oil delivery hose 1. The liquid inlet valve is connected to the oil well outlet pipeline, and the liquid outlet is connected to the inlet of the gas-liquid mixed transport pump; an intermediate pressure sensor is designed on the outlet pipeline of the injector.

The air inlet of the injector is connected to the casing gas outlet provided at the wellhead through an electric valve, a gas flow meter, an air storage tank, an air intake valve, and an air intake hose; multiple air inlets are designed on the air storage tank. It can be connected to casing gas outlets of multiple wellheads at the same time.

The liquid inlet of the gas-liquid mixed pump is connected to the outlet of the injector, and the liquid outlet is connected to the downstream of the oil well oil pipeline through the oil hose and the liquid outlet valve. The outlet of the gas-liquid mixed pump is provided with a Outlet pressure sensor.

There are control elements and display elements in the control unit, electric valves, gas-liquid mixed pumps, gas flow meters, gas pressure sensors, intermediate pressure sensors, outlet pressure sensors and other electrical components are respectively connected to the interfaces of the control unit.

The beneficial effects of the invention are: since the sleeve gas is recovered, environmental pollution and waste caused by the combustion or emptying of the sleeve gas are avoided. The device of the present invention realizes automatic control, reduces labor costs, and realizes refined management of recovery; when casing gas enters the oil pipeline, it can be inflated to reduce viscosity and reduce the dynamic viscosity of crude oil transportation; multiple interfaces are designed on the gas storage tank, which can be collected at the same time The casing gas of multiple oil wells improves the recovery efficiency; the whole device is made into a skid type, which is convenient for installation and transportation, and can be recovered in turn in multiple oil areas to improve the utilization rate of the device.

Description of drawings

Accompanying drawing 1 is a structural representation of the present invention.

In the figure: 1. Oil outlet pipeline, 2. Control unit, 3. Liquid inlet valve, 4. Oil delivery hose, 5. Injector, 6. Electric valve, 7. Gas flow meter, 8. Gas pressure sensor, 9. Air storage tank, 10. Inlet valve, 11. Intake hose, 12. Gas-liquid mixed delivery pump, 13. Intermediate pressure sensor, 14. Outlet pressure sensor, 15. Liquid outlet valve, 16. Casing gas Export.

Detailed ways

The structure and implementation of the present invention will be described in detail below in conjunction with the accompanying drawings.

The whole device includes injector 5, gas-liquid mixing pump 12, liquid inlet valve 3, liquid outlet valve 15, electric valve 6, air intake valve 10, gas storage tank 9, gas pressure sensor 8, gas flow meter 7, electric The valve 6, the control unit 2, etc. are integrally made into a skid-mounted block. The liquid inlet of the ejector 5 is connected to the upstream of the oil well outlet pipeline 1 through the oil delivery hose 4 and the liquid inlet valve 3, and the liquid outlet is connected to the inlet of the gas-liquid mixed transport pump 12; An intermediate pressure sensor 13 is designed to facilitate the observation of the working state of the injector 5; the outlet of the gas-liquid mixed pump 12 is connected to the downstream of the oil well outlet pipeline 1 through the oil delivery hose 4 and the outlet valve 15, and the outlet is designed An outlet pressure sensor 14 is provided to observe the working conditions of the gas-liquid mixing pump 12 . The air inlet of the ejector 5 is connected to the gas outlet 16 of the wellhead casing through the electric valve 6, the gas flow meter 7, the gas storage tank 9, the air intake valve 10, the oil delivery hose 4, etc.; the gas storage tank 9 is designed with Multiple air inlets can be connected to the casing gas outlets 16 of multiple wellheads at the same time to improve recovery efficiency; the outlet of the gas storage tank 9 is provided with a gas pressure sensor 8 .

The control unit 2 is installed on the skid block, including control elements and display elements, electric valve 6, gas-liquid mixed pump 12, gas flow meter 7, gas pressure sensor 8, intermediate pressure sensor 13, outlet pressure sensor 14 and other electrical components They are respectively connected to the interfaces of the control unit 2 correspondingly.

During normal operation, both the liquid inlet valve 3 and the liquid outlet valve 15 are opened, and when the pressure of the casing gas reaches a certain value, the gas pressure sensor 8 sends a signal to the control unit 2, and the control unit 2 issues an instruction to start the gas-liquid mixed delivery pump 12 , open the electric valve 6 after a delay; the high-speed flowing liquid in the ejector 5 attracts the casing gas, mixes them and enters the mixed transport pump for pressurization, and then enters the oil well outlet pipeline 1 to realize the recovery of the casing gas. After the casing gas is recovered for a period of time, the pressure drops, and when it is lower than a certain value, the control unit 2 instructs the electric valve 6 to close first, and then closes the gas-liquid mixed delivery pump 12 after a delay.

Part of the crude oil extracted from the oil well enters the device from the upstream of the oil outlet pipeline 1 through the liquid inlet valve 3. After the crude oil flows through the nozzle of the ejector 5, since the pressure energy is converted into velocity energy, a vacuum negative pressure chamber is formed around the nozzle. The casing gas collected in the gas storage tank 9 is sucked into the negative pressure chamber, and the crude oil and the casing gas are mixed and diffused by the diffuser to reach a stable flow state. Due to the pressure drop caused by gas-liquid mixing, the pressure of the mixed fluid is lower than the pressure in the oil delivery pipeline 1, so it is necessary to input the mixed fluid into the gas-liquid mixed delivery pump 12 to increase the pressure to meet the normal delivery pressure of the oil production pipeline and reach the delivery pressure. The mixed fluid enters the downstream of the oil outlet pipeline 1 for normal delivery after passing through the outlet valve 15 . A group of air inlet pipes are arranged on the gas storage tank 9, and each air inlet pipe has an air inlet valve 10, and each air inlet valve 10 can be connected with the casing gas outlet 16 of a well. When the pressure of the casing gas collected by the gas storage tank 9 reaches a certain value, the gas pressure sensor 8 transmits the pressure signal to the control unit 2, and the control unit controls the gas-liquid mixed delivery pump 12 to open and the electric valve 6 to open with a delay to start the casing. Gas recovery. When the casing gas pressure in the gas storage tank 9 drops to a certain value, the gas pressure sensor 8 feeds back the pressure signal to the control unit 2, and the control unit 2 instructs the electric valve (6) to close first, and then the gas-liquid mixed delivery pump 12 delays Closed, casing gas recovery paused. When the casing gas pressure accumulated in the gas storage tank 9 reaches a certain value again, the recovery process starts again.

There are control elements and display elements in the control unit 2, the control elements can realize the automatic control of the recovery device, no manual operation is required during normal operation; the display elements can display the pressure and flow of each part in real time.

The system also has a safety protection function. When the gas-liquid mixed pump 12 or the injector 5 fails, the pressure behind the injector 5 rises sharply, and the intermediate pressure sensor 13 feeds back the signal to the control unit 2, which is determined by the control unit 2 The electric valve 6 and the gas-liquid mixed delivery pump 12 are closed sequentially, and the control panel sends out a warning signal.

The above is only one embodiment of the present invention, and other structural forms based on the principle of the present invention are within the scope of the present invention.

Claims (2)

1. An injection pressurized casing gas recovery device, characterized in that: the whole device includes an injection device (5), a gas-liquid mixed delivery pump (12), a liquid inlet valve (3), a liquid outlet valve (15 ), air intake valve (10), gas storage tank (9), gas pressure sensor (8), gas flow meter (7), electric valve (6), and control unit (2), and is made into a skid-mounted block as a whole; The liquid inlet of the injector (5) is connected to the upstream of the oil well outlet pipeline (1) through the oil delivery hose (4) and the liquid inlet valve (3), and the liquid outlet is connected to the gas-liquid mixed delivery pump (12). The inlet is connected; the outlet pipeline of the injector (5) is designed with an intermediate pressure sensor (13); the control unit (2) contains control elements and display elements, electric valve (6), gas-liquid mixed pump (12), The gas flow meter (7), gas pressure sensor (8), intermediate pressure sensor (13) and outlet pressure sensor (14) are respectively connected to the interface of the control unit (2); When the injector (5) fails, the pressure behind the injector (5) rises sharply, and the intermediate pressure sensor (13) feeds back the signal to the control unit (2), and the control unit (2) decides to turn the electric valve (6) , the gas-liquid mixed pump (12) is closed in turn, and the control panel sends out a warning signal; The air valve (10) and the air inlet hose (11) are connected to the wellhead casing gas outlet (16); the gas storage tank (9) is designed with multiple air inlets, which can be connected to the casing gas of multiple wellheads at the same time. Export. 2. The injection pressurized casing gas recovery device according to claim 1, characterized in that: the liquid inlet of the gas-liquid mixed pump (12) is connected to the outlet of the ejector (5), and the liquid outlet The oil delivery hose (4) and the delivery valve (15) are connected to the downstream of the oil delivery pipeline (1) of the oil well, and there is an outlet pressure sensor (14) at the outlet of the gas-liquid mixed delivery pump (12).