RU2779979C1 - Bypass valve - Google Patents

Abstract

FIELD: oil industry.

SUBSTANCE: invention relates to the oil industry and is intended to maintain the calculated pressure drop in the annular space by bypassing the annulus gas into the discharge pipeline. The bypass valve contains a housing, a piston, a pusher and a check valve installed on the pipeline connecting the annular space with the flow line. The housing is made detachable, the parts of which are connected by a coupling, contains a seat at the place of the split and a spring-loaded end valve resting on the seat. The pusher is made hollow and is provided at the end with an external ledge, which is included in the reciprocal groove on the saddle. The end valve is installed with the possibility of covering the outer protrusion of the pusher and with the formation of an annular chamber with the housing of the split housing, hydraulically connected by holes in the housing of the seat with the axial channel of the split housing. The check valve seat is provided with a hollow stem with a washer at the end connected to the adapter to form an annular chamber connected by holes in the washer to the axial channel of the adapter and closed by a spring-loaded annular piston. The non-return valve is pressed against the seat by a spring-loaded rod passed through an adjusting nut with holes. The pusher is provided with an internal protrusion on which the spring-loaded piston rests, and drainage holes are made in the housing of the pusher under the piston.

EFFECT: providing the possibility of maintaining the calculated pressure drop between the annular space and the flow line, optimizing the operation of the rod pump by maintaining the necessary pressure at the pump intake, which exceeds the saturation pressure, and the possibility of supplying technical fluids to the annular space of the well and its development after replacing the rod pump.

1 cl, 4 dwg

Description

The invention relates to the oil industry and is intended for bypassing annular gas into the flow line, maintaining the calculated pressure drop.

An automatic device for bypassing annular gas is known (see Pat. RF No. 2318983, IPC E21B 34/06, publ. 10.03.2008)

The device consists of a special coupling, which is part of the tubing string. In the special coupling there is a check valve of the annular type, in which the hydraulic channel is made to connect the annulus with the axial channel of the production string. The check valve is made in the form of a sleeve and is installed so that in the upper position it opens a hole in the valve for bypassing the annular gas.

This prevents the outflow of the gas-liquid mixture from the axial channel of the tubing string into the annulus when the gas pressure in the annulus decreases below the formation fluid pressure in the tubing at the device placement level. The seal promotes the supply of a gas-liquid mixture from the axial channel of the tubing string to the branched hydraulic channel.

The length of the seal is chosen so as not to block the inlet and outlet openings of the hydraulic channel, which has a narrowing in the middle part.

During operation of the device, the seal blocks the direct flow of the gas-liquid mixture, with its supply through the inlet opening into the branched hydraulic channel. At the point of constriction, when the gas-liquid mixture moves, a pressure drop occurs.

The non-return valve sleeve is under annular gas overpressure, which leads to the displacement of the sleeve to the upper position, with the bypass of the annular gas and its mixing with the gas-liquid mixture, which is fed through the inlet into the axial channel of the tubing string under the seal located in the axial channel of the special coupling. When the gas pressure in the annulus decreases, compared to the pressure of the gas-liquid mixture, in the place of narrowing of the branched hydraulic channel, under the action of pressure, the check valve sleeve moves down, with the gas-liquid mixture spout blocked through the narrowing channel, with a corresponding interruption of supply during the suction period.

The disadvantages of the device include

- there is uncertainty in the work;

- to replace the rod pump, it is required to lift all equipment from the well;

- the calculated pressure drop between the annulus and the axial channel of the tubing string cannot be maintained.

An automatic valve device for bypassing annular gas is known (see Pat. RF No. 2305171, IPC E21B 34/06, publ. 27.08.2007).

The automatic valve device has a check valve and a L-shaped hydraulic channel, which is made in the coupling in the tubing string. The sleeve is placed in the well at the level of the well fluid. The inner surface of the coupling is made convex relative to the outer surface.

At the device placement level, a cylinder of larger diameter is located, which is larger than the diameter of the pump rods. The length of the cylinder is assumed to be greater than the stroke length of the rod pump plunger. At the ends of the coupling there are centralizers covering the cylinder.

The hydraulic channel in the coupling enters the center of the segment part where the cylinder is located. A rod pump is placed in the zone of the productive formation, the plunger of which is connected by rods to the cylinder. Bypass of annular gas occurs as follows:

During operation of the sucker rod pump, the well fluid passes through the annular space formed by the cylinder and the segmented part of the coupling, with a decrease in pressure in the fluid flow. This leads to the opening of the check valve and bypassing the annulus gas through the hydraulic channel from the annulus to the axial channel of the tubing string above the cylinder, with a decrease in gas pressure in the annulus.

The disadvantages of the design include:

- replacement of rod pumps can be carried out only when lifting the entire assembly, including the special coupling;

The technological gap between the coupling segment and the cylinder is the hydraulic resistance. However, it is not possible to obtain a sufficient pressure drop to open the check valve at such a formation fluid flow rate. This is due to the fact that the delivery volume of the rod pump is limited by the number of strokes and depends on the filling of the cylinder. A simple calculation can determine the flow rate of formation fluid in the annular gap between the sleeve and the cylinder. The flow rate of the formation fluid is estimated at several centimeters per second, which is clearly not enough for the normal operation of the device;

- the design of the device does not make it possible to regulate the pressure drop between the annulus and the axial channel of the tubing string.

Known automatic valve device (see AS USSR. No. 625021, E21B 33/03, publ. 25.09.78), taken as a prototype. The device consists of a housing, with a spring-loaded latch mounted to interact with a piston, pivotally connected through a pusher, with a damper placed in the axial channel of the flow line and pivotally connected to its inner wall. The damper is installed in front of the check valve. The piston rests on annular corrugated tubes. The housing cavity above the piston is hydraulically connected by a pipeline to the annular space of the well. The check valve is installed in the axial channel of the pipeline hydraulically connected to the intercut space of the well. The cavity above the non-return valve is connected by a hole with the flow line behind the damper.

The device works as follows.

With an increase in gas pressure in the annular space, perceived by the cross-sectional area of the piston, which moves down in the housing and compresses the gas under the piston, the pusher acts on the damper, which rotates on a hinge and closes the free section of the flow line channel, with the creation of a zone of reduced liquid pressure. The check valve opens and gas from the annular space enters the flow line until the pressure between the annular space and the pipeline cavity behind the damper equalizes. The check valve closes. After that, the pressure force of the compressed gas in the cavity under the piston moves the latter upwards, with the damper returning to its original position, with the recovery of the throughput of the flow line.

To exclude the intermediate position of the damper, spring-loaded clamps are designed, which perceive part of the force from the gas pressure on the piston.

As the pressure in the annulus increases, the cycle repeats.

The disadvantages of the design include:

- low reliability of the device, which consists in the fact that it is difficult to ensure the tightness of the cavity between the corrugated tubes; which means that there is a problem of returning the piston and damper to its original position;

- there are no conditions for maintaining the calculated pressure drop between the annular space and the flow line;

- the use of the device at low temperatures can lead to freezing of the check valve and liquid in the corrugated tubes, which can lead to their destruction and loss of device performance.

The technical result that can be obtained in the implementation of the invention:

- the possibility of maintaining the calculated pressure drop between the annulus and the flow line;

- optimization of the operation of the rod pump by maintaining the required pressure at the pump intake, which exceeds the saturation pressure;

- the possibility of supplying technical fluids to the annular space of the well and its development after replacing the rod pump.

The technical result is achieved by the fact that the bypass valve installed on the pipeline and connecting the annular space with the flow line is equipped with a check valve, a housing with a piston and a pusher. The body is made detachable, the parts of which are connected by a coupling and contain a seat in the place of the connector, on which the spring-loaded end valve rests, the pusher is made hollow and is provided at the end with an external protrusion entering the annular groove on the seat. The end valve is installed with the possibility of covering the outer protrusion of the pusher and forming an annular chamber with the body of the split housing, hydraulically connected by holes in the seat, with the axial channel of the split housing. The check valve seat is provided with a hollow stem with a washer at the end connected to the adapter to form an annular chamber connected by holes in the washer to the axial channel of the adapter and closed by a spring-loaded annular piston. The non-return valve is pressed against the seat by a spring-loaded stem passed through an adjusting nut with holes. The pusher is provided with an internal protrusion on which the spring-loaded piston rests, and drainage holes are made in the pusher under the piston.

The design of the bypass valve is illustrated by drawings, which show:

figure 1 - General view of the device in the section in the original closed position;

- on the figure 2 - a general view of the device in the section at the time of bypass of the annulus gas, with a calculated pressure drop;

- on the figure 3 - the position of the device parts in the mode of supplying the killing fluid into the annulus of the well;

- in figure 4 - the general layout of the equipment when equipping the wellhead with a bypass valve.

The bypass valve consists of a split housing 1, consisting of two parts connected by a coupling 2. In the axial channel 3 of the split housing 1, a seat 4 is installed with a spring-loaded pusher 5, provided with an external protrusion 6, which is included in the reciprocal groove 7 on the seat 4. The saddle 4 rests on spring-loaded end valve 8, with the possibility of covering the outer protrusion 6 of the pusher 5. Between the end valve 8 and the inner surface of the split housing 1, an annular chamber 9 is formed, hydraulically connected by holes 10 in the seat 4, with the axial channel 3 of the split housing 1.

From above, the annular chamber 9 is blocked by an annular piston 11 resting on a spring 12, which presses it against the seat 13 of the check valve 14. The seat 13 is connected to a hollow rod 15, at the upper end of which a washer 16 is installed, fixed on the lower end of the adapter 17 associated with the pipeline 18 (see Fig. 4).

Between the hollow stem 15 and the inner surface of the split housing 1, an annular chamber 19 is formed, hydraulically connected by holes 20 in the washer 16, with an axial channel 21 of the adapter 17. The check valve 14 is pressed against the seat 13 by the spring 22 mounted on the rod 23, the upper end of which is passed through an adjusting nut 24 with holes 25 connecting the axial channel 26 of the hollow rod 15 with the axial channel 21 of the adapter 17. a number of drainage holes 30. The device assembly is included in the pipeline 18 (see Fig. 4) through the adapter 17. The pipeline 18 connects the annulus 31, through the valves 32 with the flow line 33. The well is equipped with a rod pump 34, as part of the tubing string 35, driven by a string of 36 sucker rods.

Bypass valve operation.

The assembled device is tied as part of wellhead fittings, a well equipped with a rod pump 34.

During operation of the rod pump 34 in wells with a high GOR, gas accumulates in the annular space 31, with increasing pressure. Maintained design differential pressure between the annulus 31 and the flow line 33 is at a level exceeding the value of the saturation pressure. With an increase in gas pressure in the annulus 31, it is perceived by the pusher 5 and the piston 29. Under this pressure, the end valve 8 is located, covering the outer protrusion 6 of the pusher 5. The force from the gas pressure on the end valve 8 is less than the total force from the pusher 5 with the piston 29 The pusher 5 with its outer protrusion 6 acts on the end valve 8, compressing the spring 12 and the spring of the pusher 5, and separates the end valve 8 from the seat 4 (see Fig. 2). The gas from the axial channel 3 of the split body 1 through the holes 10 in the body of the seat 4 and the gap between the seat 4 and the end valve 8 enters the axial channel of the end valve 8, with the separation of the check valve 14 from the seat 13 and the release of the gas flow into the axial channel 26 of the hollow rod 15. Next, the gas flow through the holes 25 in the adjusting nut 24 goes into the axial channel 21 of the adapter 17, with the release into the pipeline 18 (see Fig. 4).

When the gas pressure drops to the calculated values, the end valve 8 sits on the seat 4 by the force of the compressed spring 12, with the gas supply to the check valve 14 stopped.

The pusher 5 after separation of the mechanical valve 8 from the seat 4 returns to its original position by the force of the compressed spring with the entry of the external protrusion 6 into the reciprocal groove 7 on the seat 4. With an increase in gas pressure in the annulus 31, the cycle repeats. To ensure the supply of process fluid into the well, the flow line 33 is connected to the pipeline 18. When the process fluid is supplied under pressure through the bypass valve, the latter is fed through the holes 20 in the washer 16 into the annular chamber 19, with an effect on the annular piston 11, with its separation from the seat 13, with the formation of a hydraulic channel for supplying process fluid to the axial channel of the mechanical valve 8 and further to the axial channel 27 of the pusher 5. Under the pressure of the process fluid, the piston 29 moves in the axial channel 27 of the pusher 5, with the spring compressed and located below the drainage holes 30, which ensures the supply of process fluid into the axial channel 3 of the detachable housing 1 and further into the annulus 31 of the well. At the end of the supply under pressure of the process fluid, the annular piston 11 and the piston 29 return to their original position by the efforts of the compressed springs. The annular piston 11 sits on the seat 13 of the check valve 14. The piston 29 sits on the protrusion 28, with the supply of process fluid to the drainage holes 30 stopped.

Claims (1)

A bypass valve containing a check valve installed on a pipeline connecting the annular space with the flow line, a body with a piston and a pusher, characterized in that the body is made split, the parts of which are connected by a coupling, contains a seat at the place of the split and a spring-loaded end valve resting on the seat , the pusher is hollow and provided at the end with an external protrusion that enters the reciprocal groove on the seat, the end valve is installed with the possibility of covering the external protrusion of the pusher and with the formation of an annular chamber with the body of the split housing, hydraulically connected by holes in the body of the seat, with the axial channel of the split housing, moreover, the check valve seat is equipped with a hollow stem with a washer at the end connected to the adapter, with the formation of an annular chamber connected by holes in the washer, with the axial channel of the adapter and blocked by a spring-loaded annular piston, the check valve is pressed against the seat by a spring-loaded rod passed through the adjusting nut from the hole Thus, the pusher is provided with an internal protrusion on which the spring-loaded piston rests, and drainage holes are made in the body of the pusher under the piston.

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