RU2835288C1 - Reversible check valve - Google Patents

Abstract

FIELD: pipeline valves.

SUBSTANCE: invention relates to pipeline valves and can be used in oil industry during production of formation fluid, preventive maintenance, flushing and well development. Valve comprises cylindrical housing 1 connected to subs 2 and 3. In housing 1 there are multidirectional holes 4 and 5 connected to non-intersecting axisymmetric channels 6 and 7 respectively. In holes 4 and 5 there are seats 8 and 9 and shutoff elements (balls) 10 and 11, which form valves of direct and reverse action, respectively. In housing 1 there is through hole 12 for passage of flushing fluid, which connects the cavity of the reverse-acting valve and channel 6. Housing 1 is equipped with limiter 13 of axial movement of ball 10. In limiter 13 holes 14 are made. Ball 11 is pressed by spring 15 by means of stop 16. To adjust compression of spring 15, its second end is equipped with adjusting nut 17. At that, stop 16, spring 15, adjusting nut 17 are sequentially arranged in stepped cylindrical housing 18, which is installed in hole 5, the second end of housing 18 is tightly closed by cover 19. In upper part of housing 18 there are holes 20 for passage of flushing liquid. Channel 6 is equipped with flushing fluid inlet branch pipe 21. In sub 2 above inlet branch pipe 21 protective grid 22 is installed, which protects elements of reversing valve from damages.

EFFECT: increasing the operational reliability and maintainability of the valve.

5 cl, 3 dwg

Description

The invention relates to pipeline fittings and can be used in the oil industry, in particular in downhole production equipment, and can be used in the extraction of formation fluid, preventive work, flushing and development of a well.

A known reversible check valve (RU No. 179228 C1, F16K 15/10, publication date 04.05.2018) comprises a cylindrical body with an opening in which direct and reverse action valves are placed, including shut-off elements with seating seats, with inlet and outlet channels for the passage of liquid, a return spring for the reverse action valve interacting with an adjusting nut, wherein the shut-off element of the reverse action valve is placed with the possibility of interacting with a stop mounted on the second end of the return spring, provided with a seating hole for the shut-off element of the reverse action valve and openings for the passage of liquid, wherein the return spring for the reverse action valve is made in the form of a package of sequentially assembled disc springs. The disadvantages of the known valve are:

- the return spring of the reverse-action valve is constantly exposed to the flow of formation fluid during operation, which leads to the deposition of mechanical impurities and ASPO on it; as a result of clogging of the spring, the valve may fail to operate, which reduces the reliability of the reversible valve and makes it impossible to flush the well;

- the adjusting nut and its running thread are also exposed to the formation fluid with mechanical impurities contained in it, which will lead to jamming of the nut, impossibility of adjusting the spring, and failure of the reversing valve;

- deposition of mechanical impurities and paraffin in the annular gaps formed by the inner surface of the half-housings and the outer surface of the module stages, which can lead to failure of the reversing valve and the impossibility of flushing the well after long-term operation, which reduces the reliability of the reversing valve.

A known non-return valve (patent No. 2449192, IPC F16K 15/04, publication date 27.04.2012) comprises a cylindrical body with an opening in which direct and reverse-action valves are placed, including shut-off elements with seating seats with inlet and outlet channels for the passage of liquid, a return spring for the reverse-action valve interacting with an adjusting nut, the valve is provided with a stepped cylindrical valve module installed in a stepped opening of the body with the formation of annular gaps, while multidirectional openings are made in the module for installing seating seats of direct and reverse-action valves, located on an axis coinciding with the axis of the body, connected to non-intersecting inclined, axisymmetric outlet and inlet channels for the passage of liquid, respectively, while the shut-off element of the direct-action valve and the limiter of its movement are installed in the upper part module, and the shut-off element of the check valve is located in the lower part of the module with the possibility of interaction with a stop installed on the second end of the return spring, provided with a mounting hole for the shut-off element of the check valve and holes for the passage of liquid.

The disadvantages of the known valve are:

- corrosion of the check valve spring due to constant contact with formation fluid during operation, deposition of mechanical impurities and ASPO, which leads to impossible adjustment of the spring, jamming, its destruction and failure of the valve, which reduces the operational reliability of the valve;

- the adjusting nut and its running thread are also exposed to the formation fluid with mechanical impurities contained in it, which will lead to jamming of the nut during valve operation, impossibility of adjusting the spring, failure of the reversing valve and the need for its repair in terms of replacing the adjusting nut and spring. All this leads to a temporary suspension of tripping operations at the well, and ultimately to a decrease in well performance;

- deposition of mechanical impurities and paraffin in the annular gaps formed by the inner surface of the half-housings and the outer surface of the module stages, which can lead to failure of the reversing valve and the impossibility of flushing the well after long-term operation, which reduces the reliability of the reversing valve;

- when carrying out preventive maintenance, the flushing fluid also passes between the turns of the compressed spring, which increases the hydraulic resistance to the flow of fluid and accelerates the wear of the spring, which also reduces the reliability of the valve and leads to its accelerated failure;

- making the input and output channels inclined reduces the hydrodynamic resistance to the liquid flow and increases the likelihood of clogging of the channels with mechanical impurities, which reduces the operational reliability of the valve;

- low maintainability of the device, impossibility of disassembling the valve due to the difficulty of unscrewing the threaded adjustment nut and replacing the spring, caused by the accumulation of mechanical impurities and ASPO deposits on the nut thread and corrosion of the spring.

The objective of the invention is to create a reversible valve that eliminates the shortcomings of analogues and ensures operational reliability and maintainability.

The technical result consists in increasing the reliability of the device, maintainability, and increasing the service life by eliminating jamming and destruction of adjustable structural elements under the influence of an aggressive environment and solid particles contained in the formation fluid.

The specified technical result is achieved in that the check valve is a reversible valve comprising a cylindrical body connected to adapters, the body contains direct and reverse acting valves including shut-off elements with seating seats, with inlet and outlet channels for the passage of liquid, a return spring for the reverse acting valve interacting with an adjusting nut, the body contains multidirectional openings for installing the seating seats of the direct and reverse acting valves, wherein the shut-off element of the direct acting valve and the limiter of its movement are installed in the upper part of the body, and the shut-off element of the reverse acting valve is located in the lower part of the body with the possibility of interacting with a stop installed on the second end of the return spring, according to the invention, the multidirectional openings for installing the seating seats of the direct and reverse acting valves are located on parallel axes, relative to the axis of the body, connected to non-intersecting parallel axisymmetric outlet and inlet channels for the passage of liquid, respectively, a through hole is made in the body, for passage of the flushing fluid, connecting the cavity of the check valve and the outlet channel of the direct-acting valve, the inlet channel of the check valve is provided with a curved branch pipe for the inlet of the flushing fluid, wherein the spring, stop and adjusting nut are installed in a protective cylindrical body, one end of which is hermetically sealed with a lid, the second end of the protective body, provided with transverse holes for the passage of flushing fluid, is installed using a threaded connection in the lower part of the hole for installing the seat of the check valve.

The technical result is achieved by the fact that the creation of multidirectional holes for the installation of direct and reverse action valve seats, located on parallel axes relative to the housing axis, and connected to non-intersecting parallel axisymmetric outlet and inlet channels for the passage of liquid, respectively, makes it possible to reduce the hydrodynamic resistance to the liquid flow and the likelihood of clogging the channels with mechanical impurities, which increases the operational reliability of the device.

The technical result is achieved by the fact that the implementation of the stop, spring, adjusting nut, cover in the protective housing in the form of a single assembly - module allows to protect the spring and adjusting nut of the check valve from corrosion from constant contact with the formation fluid during operation, from the deposition of mechanical impurities and ASPO, jamming and destruction of the control elements, failure of the valve, which allows to increase the operational reliability and increase the service life of the valve, and also improves the ease of use, allowing for quick installation / replacement of the module in the valve body, increases the maintainability of the valve due to the interchangeability of the module.

The technical result is achieved by the fact that the upper adapter is equipped with a protective grid installed above the inlet pipe, which allows protecting the elements of the reversible valve from damage, which increases the reliability of the valve.

The technical result is achieved by the fact that the bending angle of the branch pipe is 60-90 degrees, which reduces the likelihood of clogging of the flushing channels with impurities contained in the formation fluid.

The presence of these features allows us to draw a conclusion about the novelty of the technical solution.

When comparing the claimed solution with other technical solutions in this field of technology, no set of features distinguishing the claimed solution from the prototype was identified, which allows us to conclude that the technical solution meets the criterion of “inventive step”.

Thus, the claimed solution is new, has an inventive step, and is industrially applicable.

Fig. 1 shows a general view of the check reversible valve, the shut-off elements are closed. Fig. 2 shows the check reversible valve with an ascending flow of liquid. Fig. 3 shows the check reversible valve with a reverse flow of liquid (flushing) during preventive maintenance.

The check reversible valve comprises a cylindrical body 1 (Fig. 1) connected to adapters 2 and 3 by means of a threaded connection. In the body 1, multidirectional openings 4 and 5 are made, connected to non-intersecting axisymmetric channels 6 and 7, respectively, the dimensions of which depend on the flow area of the check reversible valve. In openings 4 and 5, annular seats 8 and 9 and shut-off elements (balls) 10 and 11 are installed, forming direct and reverse action valves, respectively.

In the housing 1 there is a through hole 12 for the passage of the flushing liquid, connecting the cavity of the check valve and the channel 6. In the housing 1 there is a limiter 13 of the axial movement of the ball 10 installed by means of a threaded connection. In the limiter 13 there are openings 14 for the passage of liquid. The ball 11 is pressed by a spring 15 by means of a stop made in the form of a stepped rod 16. To regulate the compression of the spring 15, its second end is provided with an adjusting element made in the form of an adjusting nut 17 installed by means of a threaded connection in a cylindrical stepped protective housing 18. In this case, the rod 16, the spring 15, the adjusting nut 17 are successively placed in the protective housing 18, which is installed by means of a thread in the opening 5 of the housing 1. The second end of the protective housing 18 is hermetically closed by a cover 19, for example, by means of a thread. The body 18 with the parts installed in it (rod 16, spring 15, adjusting nut 17, cover 19) form a single assembly unit (module), ready for installation in the opening 5 of the body 1 of the valve. In the upper part of the protective body 18, transverse openings 20 are made for the passage of the flushing liquid. The channel 7 is provided with an inlet (receiving) branch pipe 21 for the entry of the flushing liquid. Branch pipe 21 is installed in the channel 7 using a threaded connection and is made bent at an angle of 60-90 degrees. Branch pipe 21 prevents clogging of channel 7 of the reverse valve with mechanical impurities. In the adapter 2, above the inlet branch pipe 21, a protective grid 22 is installed, protecting the elements of the reversible valve from damage.

The check valve operates as follows.

When the pump is turned on, under the action of the ascending flow (Fig. 2), the extracted liquid passes successively through the channel 6, the opening 4, lifts the ball 10 above the seat 8 and exits through the openings 14 of the limiter 13 and the openings of the protective grid 22 into the tubing pipe (not shown). In this case, the check valve is closed, since the ball 11 is pressed by the spring 15 by means of the stop 16 to the seat 9.

When the pump stops under the action of the column of formation fluid, a pressure difference occurs between the zones located before and after the check valve, and the ball 10 sits on the seat 8, blocking the return flow of fluid into the channel 6. In this case, the check valve remains closed (the ball 11 is pressed by the spring 15 by means of the stop 16 to the seat 9). Thus, the column of fluid is held in the tubing string, preventing the reverse rotation of the working parts of the pump.

The value of the opening pressure of the reverse action (flushing valve) is adjusted before its installation, it should exceed the pressure of the liquid column during extraction. This is achieved by adjusting the spring 15 by means of the adjusting nut 17.

During preventive maintenance work related to flushing equipment from salt deposits, paraffin hydrates and other solid formations, and carried out after stopping the pump and closing the direct-acting valve, flushing fluid is fed into the tubing string under a pressure exceeding the operating pressure, which passes through the protective grid 22 (Fig. 3), enters the inlet pipe 21, through the channel 7 into the opening 5 and, overcoming the elastic force of the spring 15, presses the ball 11 away from the seat 9 and presses it against the stop 16, opening the openings 20 of the protective housing 18. Then the flushing fluid passes through the transverse openings 20 of the housing 18, the throughput opening 12 and exits, bypassing the adjusting elements spring 15 and the adjusting nut 17, through the channel 6 to the pump, ensuring its flushing. After filling with the required amount of liquid, the pressure above the valve is reduced, which leads to its closing and the cessation of the supply of liquid to the column.

The use of a non-return valve of the proposed design allows to increase the operational reliability and maintainability of the device.

Claims (5)

1. A reversible check valve comprising a cylindrical body connected to adapters, the body accommodating direct and reverse acting valves including shut-off elements with seating seats, with inlet and outlet channels for the passage of liquid, a return spring for the reverse acting valve interacting with an adjusting nut, the body having multidirectional openings for installing the seating seats of the direct and reverse acting valves, wherein the shut-off element of the direct acting valve and the limiter of its movement are installed in the upper part of the body, and the shut-off element of the reverse acting valve is located in the lower part of the body with the possibility of interacting with a stop installed on the second end of the return spring, characterized in that the multidirectional openings for installing the seating seats of the direct and reverse acting valves are located on parallel axes relative to the axis of the body, connected to non-intersecting parallel axisymmetric outlet and inlet channels for the passage of liquid, respectively, a through hole is made in the body for the passage of flushing fluid, connecting the cavity of the check valve and the outlet channel of the direct-acting valve, the inlet channel of the check valve is provided with a curved branch pipe for the entry of flushing fluid, while the spring, stop and adjusting nut are installed in a protective cylindrical body, one end of which is hermetically sealed with a lid, the second end of the protective body, provided with openings for the passage of flushing fluid, is installed using a threaded connection in the lower part of the opening for installing the seat of the check valve. 2. A reversible check valve according to paragraph 1, characterized in that the protective housing, stop, spring, adjusting nut, and cover are made in the form of a single assembly (module). 3. A reversible check valve according to item 1 or 2, characterized in that the stop is made in the form of a stepped rod. 4. A reversible check valve according to item 1, characterized in that the bending angle of the branch pipe is 60-90 degrees. 5. A reversible check valve according to item 1, characterized in that the upper adapter is equipped with a protective grid installed above the inlet pipe.