RU203710U1 - COMPRESSOR UNIT FOR GAS SELECTION FROM THE OUTLET SPACE OF THE BREW OF OIL WELLS - Google Patents

Abstract

The proposed utility model relates to the oil industry and can be used to extract gas from a cluster of oil wells during the flooded period of their operation and to inject it into a gathering oil pipeline. The purpose of the proposed utility model is to simplify the gas ejection system and increase its efficiency by directing a water-gas mixture from the ejector outlet. directly into the oil collection pipeline, bypassing the separator Compressor unit for gas extraction from the annulus of the cluster of oil wells, including a sump with lower inlet and outlet risers, respectively, for introducing the wells of the cluster into the sump and its removal, a centrifugal pump for taking a part of stratified formation water from part of the sump and pumping it into the working nozzle of the ejector, the line for supplying gas from the annular spaces of the well cluster to the inlet chamber of the ejector, characterized in that the discharge side of the ejector with excess pressure is connected to the collecting oil pipeline of the cluster of wells, bypassing the sump, and a control valve is installed on the gas supply line to the ejector, which is also connected to the line for sampling stratified associated produced water from the settler to the ejector. 1 ill.

Description

The proposed utility model relates to the oil industry and can be used to extract gas from a cluster of oil wells during the flooded period of their operation and pump it into the oil collection pipeline.

The separation of free gas at the intake of submersible pumps leads to its accumulation in the annulus, a rise in pressure in the latter, a decrease in pump flow, a drawdown on the formation and inflow of formation fluid into the well. In order to prevent pump failure, the annular space of the well is communicated with a flow manifold at the wellhead through a check valve.

The known device (RF Patent No. 2309240 C1. Wellhead equipment of pumps of oil wells. Appl. 09.03.2006. Publ. 27.10.2007). It includes a faceplate mounted on the production casing flange with an eccentric coupling for connecting the tee and the injection line of the well. In the flange part of the faceplate, vertical and horizontal channels are made for installing the bypass device. An increase in pressure in the annular space leads to the opening of the spring-loaded bypass valve and the passage of gas from the annular space into the pressure line of the well.

Also known wellhead check valve (RF Patent No. 2367775 C1. Check wellhead valve of oil, oil and gas wells. Appl. 06/18/2008. Publ. 09/20/2009.), Including a hollow body, equipped with inlet pipes for oil and gas, as well as a mixture withdrawal at the wellhead. When the gas pressure exceeds the liquid flow pressure by 0.02 ... 0.05 MPa, the spring-loaded valve plate is detached from the seat and passes gas from the annular space into the liquid flow in the "soft" mixing mode to create optimal thermal conditions in the valve location area. When the gas pressure drops, the disc closes the valve seat again.

The use of both of the above analogs is ineffective at increased fluid pressures in the discharge manifold. The gas pressure cannot overcome this pressure and the dynamic level of the liquid decreases before the pump is received and the gas disrupts its operation.

The extraction of gas or carbonated liquid from the annular space into the tubing string can be performed using an ejector installed inside the string. The liquid pumped out by an electric centrifugal pump enters the ejector nozzle and ejects the gas-oil mixture from the annulus into the tubing, thereby reducing the gas pressure in the annular space (RF Patent No. 1825544. Device for lifting carbonated liquid from the well. Appl. 06/29/1988. Publ. . 12.10.1992 g.).

The device has a significant drawback, consisting in significant hydraulic resistance to the movement of the liquid in the working nozzle of the ejector. They lead to a decrease in the head and flow of the submersible pump.

For utilization of associated petroleum gas and formation water, a method and device for its implementation are known (Patent RU 2317408 C2. Method for utilization of associated petroleum gas and formation water and a system for its implementation. Appl. 20.03.2006. Publ. 20.02.2008. BI No. 5 ). The separated gas and formation water from the separator are dispersed and jointly pumped into the injection well by the pump-compressor. The method makes it possible to utilize only a part of the associated petroleum gas, since the oil discharged from the separator under its own pressure contains a sufficiently large amount of gas.

A known method of utilization of associated petroleum gas (Patent RU No. 2190757 C1. Method of oil production. Appl. 05.02.2001. Publ. 10.10.2002. BI No. 28), in which the separated gas, mixing with water supplied from the outside, is injected into the injection well ... Injection of gas together with formation water into an injection well is accompanied by stratification of the water-gas mixture in the wellbore. The separated gas in the downdraft flow is forced to "squeeze" the liquid to the bottom in order to enter the reservoir. And this leads to a loss of hydrostatic pressure in the wellbore and the need to increase the pressure at the wellhead, which compensates for this loss. So, for example, at a seam top depth of 1000 m, it is necessary to raise the pressure of the mixture at the wellhead by more than 10 MPa.

Closest to the proposed method is the associated petroleum gas utilization method (Patent RU No. 2418946 C2. Associated petroleum gas utilization method. Appl. 08/20/2008. Publ. 05/20/2011). The device for implementing the method includes an oil gas separator, a pump and a liquid-gas ejector. To combine the gas utilization unit with the two-stage gas separation process flow, the separated low-pressure gas from the separator of the 2nd separation stage of the booster pumping station or the preliminary water discharge unit is sent to the suction chamber of the liquid-gas ejector, into which part of the discharged bottom water is supplied as an active medium high pressure. The water-gas mixture from the outlet of the liquid-gas ejector is directed to the intake of the separator of the 1st separation stage.

However, for the implementation of the method directly in the zones of the location of groups or clusters of wells, it is necessary to locate a pumping station or to pass a high-pressure water pipeline, which is not always the case in oil fields. In addition, the high dispersion of the water-gas mixture at the outlet of the ejector significantly impairs gas separation in the separator of the 1st separation stage.

The purpose of the proposed utility model is to simplify the gas ejection system and increase its efficiency by directing the water-gas mixture from the ejector outlet directly into the oil collection pipeline, bypassing the separator.

This goal is solved by the fact that in the known device, which includes a settler with lower inlet and outlet risers, respectively, for introducing the well production of the cluster into the settling tank and removing it, a centrifugal pump for taking a part of stratified formation water from the lower part of the settling tank and pumping it into the working nozzle of the ejector, the line for supplying gas from the annular spaces of the well cluster to the inlet chamber of the ejector, according to the utility model, the discharge side of the ejector with excess pressure is connected to the collecting oil pipeline of the cluster of wells bypassing the settler, and a control valve is installed on the gas supply line to the ejector, which is also connected to the sampling line that has stratified along - produced water from the sump to the ejector.

FIG. the diagram of the proposed compressor unit is presented. It includes a horizontal sump 1 with an upper 2 hatch, lower inlet 3 and outlet 4 risers. The outlet riser 4 with its branch 5 connects the lower part of the sump 1 with the intake of the pump 6 through line 7 through the valve 8. The pressure side of the pump 6 through line 9 through the valve 10 and the control valve 11 is connected to the working nozzle of the ejector 12. From the pressure side of the ejector 12 on line 13 a valve 14 is installed, and through the valve 15 by line 16 it is connected to the lower part of the vertical riser 3. The riser 3 is connected by line 17 through the valve 18 with the oil collection pipeline 19 of the well cluster (not shown in the figure). A burst valve 20 is installed on the oil pipeline 19, behind which the oil pipeline 19 is connected to the outlet riser 4 of the sump 1 through the check valve 21 and the valve 22. On the line 7 for supplying liquid to the pump 6, a valve 23 is installed to drain the liquid.

The inlet chamber of the ejector 12 by line 24 through the valve 25 communicates with the annular spaces of the well cluster (not shown in the figure). The intake of the ejector 12 by line 26 is also connected to the control valve 11.

The upper end of the riser 4 is installed in the sump at a level of about 3/4 of its diameter. The upper end of the riser 3 is set at approximately 1/2 of its diameter.

The operation of the compressor unit is as follows.

Before starting the compressor unit in operation, valves 8, 10, 14, 15 and 20, as well as valve 23 remain open, and valves 18, 22 and 25 are closed. The installation is launched by opening the valves 18 and 22 and closing the burst valve 20. The production of a cluster of water-cut wells with a gas phase through the valve 18, line 17 and riser 3 will enter the middle-height part of the settler 1 and stratify into gas, oil, containing part of emulsified water and free (stratified) water. The accumulation of free gas in the upper part of the settler 1 will lead to the "squeezing" of the liquid level in the settler 1 to the upper end of the riser 4. Further, all three phases of formation production will enter the riser 4. The accumulating gas will further squeeze out the liquid level already in the riser 4, bringing it to the oil collection pipeline 19 behind the valve 20, after which the gas phase will be pumped out along with the liquid through the pipeline 19. The stratified associated water will accumulate in the lower part of the settling tank 1.

Next, the centrifugal pump 6 is started and the valves 8, 10, 14 and 25 are opened, as well as the valve 15 is closed. Gas from the annular spaces of the well cluster will flow through the line 24 through the valve 25 into the receiving chamber of the ejector 12. The stratified water from the lower part of the sump 1 through outlet 5 through line 7 will enter the pump intake 6 and be pumped under pressure through line 9 into the working nozzle of the ejector 12. From the outlet of the ejector 12, the water-gas mixture under excess pressure through line 13 through the valves 14 and 22 will be pumped into the pipeline 19, already bypassing the sump 1. Thus, there will be no need to stratify the water-gas mixture to use water as an active medium in the ejector.

The presence of a check valve 21 will prevent the flow of the water-gas mixture into the sump 1. Control of the water taken by the pump 6 for the presence of oil is carried out by analyzing the sample taken from the tap 23. If necessary, to accelerate the stratification of water in the sump 1, an additional the amount of demulsifier.

The levels of the location of the upper ends of the risers 3 and 4 in the sump 1 correspond to the optimal ratios of the volumes of liquid in the sump and the sump itself.

The pump operation parameters are selected on the basis of the conditions for achieving the calculated volume of gas ejection from line 24 and the pressure at the outlet of the ejector, which ensures the flow of separated gas from the separator 1 into the oil field header 19.

During the operation of the well cluster, changes in the modes of gas flow into line 24 are possible, associated with shutdowns of individual wells for workover, the commissioning of a new well and other reasons. This will lead to a slight change in the pressure in the receiving chamber and a violation of the ejector 12 operation mode. Installation of the control valve 11 allows you to change the position of the valve shut-off element when the pressure drop in lines 24 and 9 changes. the flow rate of water supplied by pump 6 will also decrease. At the same time, the flow rate of gas entering the ejector 12 will also decrease to its previous value.

And, on the contrary, a decrease in the gas pressure at the intake of the ejector will lead to an increase in the flow area of the valve 11, which contributes to an increase in the flow rate of the incoming gas.

The compressor unit thus makes it possible to reduce the pressure in the annular space of a group of wells, improve the operating conditions of downhole pumps and increase the flow of oil into the well.

The technical and economic advantages of the compressor unit are the independence of the efficiency of the ejection system from the intensity of emulsification of the water-gas mixture in the ejector and the use of the separated formation water in the sump as the active medium of the ejector.

Claims (1)

Compressor unit for gas extraction from the annular space of an oil well cluster, including a settler with lower inlet and outlet risers, respectively, for introducing the well production of the cluster into the clarifier and its removal, a centrifugal pump for taking a part of stratified formation water from the lower part of the settler and pumping it into the working nozzle ejector, a line for supplying gas from the annular spaces of the well cluster to the ejector receiving chamber, characterized in that the discharge side of the ejector with excess pressure is connected to the collecting oil pipeline of the well cluster, bypassing the sump, and a control valve is installed on the gas supply line to the ejector, which is also connected to the line selection of stratified associated produced water from the sump into the ejector.

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