RU2500883C2 - Installation for water-alternated-gas injection to oil formation - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: installation includes centrifugal pump for operating liquid pumping without gas, run-down lines for basin and liquid, two tanks with air inlet valves and pressure control valves located in the upper line, bleed-off lines and liquid pressure lines located in the lower parts and symmetrical high-pressure and low-pressure taps communicating with discharge and suction of the pump. According to invention at water input line in parallel to the main centrifugal pump there is an additional pump which discharge side communicates with operating nozzle of liquid-gas ejector, receiving chamber of the latter is connected to gas line and discharge is connected to upper parts of tanks. At the line of liquid input to ejector there is regulating valve and choke connected in series. Gate of the regulating valve is connected hydraulically to discharge of ejector and input to choke.

EFFECT: increasing injection efficiency of fluid and gas mixture.

1 dwg

Description

The installation relates to the oil industry and can be used for utilization of associated petroleum gas by pumping it into the oil reservoir together with the water of the reservoir pressure maintenance system.

For pumping a gas-water mixture into the reservoir, booster pumps are known, which are piston pumps with additional chambers that allow suction and injection of the gas phase by the created “liquid” piston / 1, 2 /. Booster pumps have low performance and low efficiency, are characterized by high energy and metal consumption.

Closest to the proposed solution is the installation for pumping a gas-liquid mixture / 3 /. It includes two containers for alternately pumping working fluid from them with a pump and thus creating a “liquid” piston in them. With a decrease in the level of the "liquid" piston in one of the containers, the gas-liquid mixture is sucked into the vacant volume. In the same period, the working fluid fills another container and displaces a previously filled gas-liquid mixture into the pressure line. Upon reaching a certain level of the working fluid in the tank, flows are switched and pumping of the working fluid into another tank from which the cycle of displacing the gas-liquid mixture into the pressure line begins. The transfer pump itself works, thus, in a continuous mode, constantly pumping liquid that does not contain a gas phase. In this regard, a centrifugal pump can be used as a pumping body, which disrupts its work when gas enters a liquid. The device allows you to pump not only a gas-liquid mixture, but also gas. The disadvantage of this device is the low efficiency of injection of a gas-liquid mixture or gas at low pressures of their entry into the tank. At low inlet pressures and high pressures in the pressure line, significant loss of stroke of the "liquid" piston in the tanks occurs due to the need to compress the gas phase from low to high pressure. With increasing pressure at the inlet to the tank, the stroke loss of the "liquid" piston decreases and the efficiency of the device increases.

The aim of the invention is to increase the efficiency of injection of a gas-liquid mixture by increasing the gas pressure at the inlet to the installation capacity.

This goal is achieved by the fact that in the known device, including a centrifugal pump for pumping a working fluid without gas, receiving lines for gas and liquids, two containers with suction and discharge valves located in the upper part, liquid collection and discharge lines located in the lower parts and communicated with the discharge and intake of the pump through symmetrically located high-pressure and low-pressure taps, an additional pump is placed on the water inlet line parallel to the main centrifugal pump, the pressure side of which is connected to the working nozzle of the liquid-gas ejector, the receiving chamber of which is connected to the gas line, and the discharge is to the upper parts of the containers, a control valve and a throttle are sequentially located on the liquid inlet line to the ejector, and the shut-off element of the control valve is hydraulically in communication with the discharge ejector and the entrance to the throttle.

In FIG. shows a diagram of the proposed device. It includes lines 1 and 2 for the flow of water and gas, inlet taps 3 and 4, pressure gauges 5 and 6, flow meters for water and gas 7 and 8, check valves 9 and 10. On the water intake line 1, pumps 11 and 12 with pressure pumps are installed valves 13 and 14. Discharge of the pump 12 through parallel three-way valves (spool type valves) 15 and 16 is connected with the lower parts of the tanks 17 and 18. The second inputs of the three-way valves 15 and 16 through the inductor 19 are connected to the intake line 1 for water, t. e. with receptions of pumps 11 and 12.

In the lower parts of the tanks 17 and 18, sensors 20 and 21 are installed for lowering the water level in the tanks 17 and 18. The flow line of the pump 11 is connected to the working nozzle of the liquid-gas ejector 22 through a sequentially located control valve 23 and the throttle 24. The receiving chamber of the ejector 22 through the non-return valve 10 is in communication with the gas supply line 2, and the ejector flow through the non-return valves 25 and 26 is in communication with the upper parts of the tanks 17 and 18. The upper parts of the containers 17 and 18 are also connected through the non-return valves with the pressure line 29 of the gas-water mixture injection in the oil reservoir. A pressure gauge 30 for controlling the injection pressure is installed on the same line. A pressure gauge 31 for controlling pressure is installed on the pressure line of the vessels.

The operation of the installation is as follows. In FIG. a cycle of injecting gas and then water into the RPM system from the tank 17 is shown. In this cycle, water from the lower part of the tank 18 through a three-way valve 16, the throttle 19 is received by the pump 12 and is pumped into the lower part of the tank 17 through a three-way valve 15 gas through the check valve 27 to the pressure line of the PPD system. At the same time, a certain amount of water will be taken from the water supply line 1 by pump 11 and supplied to the ejector 22 through the valve 23 and the throttle 24. The amount of water supplied to the ejector is set by the corresponding position of the shut-off element of the throttle 24. Water entering the ejector nozzle sucks gas from line 2 and pumps it through the check valve 26 into the tank 18. Thus, the pressure of the gas entering the tank is increased.

During the gas injection period, the pressure in the vessel may change 18. When the differential pressure acting on the shutoff valve of the valve 23 changes, its position, as well as the flow of water through it, changes. For example, with increasing pressure on the ejection of the ejector, the passage section of the valve 23 is additionally opened, which allows increasing the flow rate of water through the ejector 22. Otherwise, the flow rate of water through the valve 23 is reduced.

After the water level in the tank 18 has decreased to a minimum value, the level sensor 21 transmits a signal for connecting the three-way valves 16 and 15. In this case, the water from the vessel 17 through another passage channel of the three-way valve 15 and the throttle 19 will be received by the pump 12 and then through the switched channel of the valve 16 will be pumped into the tank 18. During this period, the gas-water mixture from the ejector 22 will be pumped into the tank 17 through the check valve 25.

Having reached the upper level in tank 18, water will continue to be pumped into the pressure line of the PPD system through the non-return valve 28. The period of water injection into the PPD system from tank 18 after the gas phase is ejected from it is determined by the amount of water entering line 1. Installation on the receiving line of the pump 12 of the throttle 19 allows you to raise the gas injection pressure in the tanks 17 and 18 to a predetermined value at which the loss of stroke of the "liquid" piston to compress the gas to be displaced into the pressure line PPD will be optimal from the technical and economic considerations. Thus, the pressure up to the throttle 19 will be much higher than the pressure at the intake of pumps 11 and 12. After the water level in the tank 17 reaches the lowest possible position, the level sensor 20 sends a signal to switch the three-way valves 15 and 16 and pumping of water in the opposite direction will begin from tank 18 to tank 17, etc.

Switching of the ejector 22 to the injection of the water-gas mixture in the tank 17 or 18 occurs automatically when switching taps 15 or 16, i.e. as soon as the pumping of water from one of the tanks begins.

The flow of the pump 11 using the throttle 24, the geometric parameters of the liquid-gas ejector, as well as the flow of the pump 12 are determined based on the volumes of water and gas supplied to the installation.

The installation can be operated in this way both in compressor mode and in pump mode.

In the first case, one of the tanks 17 or 18 is initially filled with water. When water stops flowing on line 1, pumps 11 and 12 will pump water from one tank to another and pump only the gas phase into the RPM system with its preliminary compression in the ejector 22.

The technical and economic advantage of the proposed installation is the possibility of preliminary compression of the gas phase before it is pumped by a “liquid” piston into a high-pressure network, reducing the volume of tanks and increasing the efficiency of pumping.

Information sources

1. The method of pumping a gas-liquid mixture by a piston pump and a device for its implementation. A.S. USSR, No. 714044 (authors: I.V. Belei, Yu.V. Lopatin, S.P. Oleinik). Claim 07/14/76. Publ. 02/05/80. BI No. 5.

2. Hydrocompression booster pump. RF patent №2266429 (authors: O.I. Belei, S.Yu. Lopatin, O.S. Oleinik) 07/14/2004. Publ. 12/20/2005

3. A pump for pumping a gas-liquid mixture. A.S. USSR, No. 1590687 (authors: V.G. Karmyshev, M.D. Valeev, R.Z. Akhmadishin, etc.). Claim 10/04/08. Publ. 09/07/90. BI No. 33.

Claims (1)

Installation for water-gas treatment of an oil reservoir, including a centrifugal pump for pumping a working fluid without gas, receiving lines for gas and liquid, two containers with suction and discharge valves located in the upper part, liquid collection and discharge lines located in the lower parts and communicated with a discharge and intake of a pump through symmetrically located high-pressure and low-pressure valves, characterized in that, in order to increase the efficiency of pumping a gas-liquid mixture by increasing Gas supply at the inlet to the installation’s tanks, at the water inlet line parallel to the main centrifugal pump, there is an additional pump, the pressure side of which is connected to the working nozzle of the liquid-gas ejector, the receiving chamber of which is connected to the gas line, and the discharge to the upper parts of the tanks, the fluid inlet line to the ejector is arranged in series with the control valve and the throttle, and the shutoff valve of the control valve is hydraulically connected to the ejector outlet and the inlet to the throttle.

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