Sand control regulating valve and construction process

Abstract

The invention belongs to the technical field of oil and gas field downhole tools, and particularly relates to a sand control regulating valve and a construction technology. The sand prevention regulating valve comprises a first working barrel, a second working barrel and a third working barrel, wherein at least one first through hole is formed in the barrel wall of the first working barrel; the first working barrel is sleeved with the second working barrel in a clearance mode, an annular space is formed between the first working barrel and the second working barrel, the two axial ends of the annular space are closed, and at least one second through hole is formed in the barrel wall of the second working barrel; and the switch valve is arranged in the annular space, and the switch valve is configured to close a channel between the first through hole and the second through hole in an initial state and open the channel between the first through hole and the second through hole in a working state.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of downhole tools for oil and gas fields, and particularly relates to a sand prevention regulating valve and a construction process. BACKGROUND

[0002] Oil and gas development is a systematic project covering geology, drilling, well completion, production increase, collection and transportation, etc. In recent years, with the rapid economic development, the demand for energy has increased dramatically, and oil and gas development has shifted from conventional oil and gas resources to unconventional oil and gas such as tight oil and gas, shale oil and gas, and coalbed methane. Horizontal well fracturing technology has become the mainstream technology.

[0003] Unconventional oil and gas resources are buried deep and have low porosity, and often need to be hydraulically fractured to establish oil and gas channels in the formation. In order to improve oil and gas recovery, the construction discharge of hydraulic fracturing, the amount of pumped liquid, the number of proppants, etc. are usually increased to crush the formation as much as possible. As oil and gas well production enters the middle and late stages, the formation energy gradually decreases, and the liquid loading in the oil and gas well increases, resulting in a rapid decline in oil and gas production. In order to solve the problem of increasing liquid loading in the oil and gas well, compressed natural gas, nitrogen and other high-pressure gases are usually injected into the well. The compressed gas is injected into the formation through the annulus or the tubing, reduces the density of the liquid, and then the compressed gas enters the tubing through the gas lift valve and is lifted to the surface under the circulation of the fluid, reducing the resistance of the liquid to the natural gas in the formation, thereby releasing the production capacity.

[0004] However, during the fracturing flowback and later production process, some of the proppants (ceramsite, quartz) squeezed into the formation will enter the wellbore along with oil and gas, pressure-returned liquid, etc. The conventional gas lift method does not have a sand prevention function, and the gas lift valve is easily blocked during production. In order to achieve efficient drainage and gas production in the oil and gas well, the present application provides a sand prevention regulating valve, a drainage and gas production string and a corresponding drainage and gas production process. SUMMARY

[0005] In view of the above technical problems, the present application aims to provide a sand prevention regulating valve that can improve the efficiency of drainage and gas production.

[0006] The present application also provides a construction process using the sand prevention regulating valve according to the present application, which can improve the efficiency of drainage and gas production.

[0007] According to the present application, a sand prevention regulating valve is provided, comprising:

[0008] a first working cylinder, at least one first through hole is provided on the cylinder wall of the first working cylinder;

[0009] A second working cylinder is gap-set outside the first working cylinder, an annular space is formed between the first working cylinder and the second working cylinder, axial ends of the annular space are closed, and at least one second through hole is arranged on a cylinder wall of the second working cylinder; and

[0010] A switch valve is arranged in the annular space, the switch valve is configured to close a passage between the first through hole and the second through hole in an initial state and open the passage between the first through hole and the second through hole in a working state.

[0011] In a preferred embodiment provided by the present application, the switch valve comprises an arc-shaped valve flap, upper and lower ends of the valve flap are in contact with an outer wall of the first working cylinder, and a middle part of the valve flap abuts against the second working cylinder and blocks the second through hole.

[0012] In a preferred embodiment provided by the present application, the upper and lower ends of the valve flap are in sealing abutment with the first working cylinder.

[0013] In a preferred embodiment provided by the present application, a pressure transmission hole is arranged on the cylinder wall of the first working cylinder, and the pressure transmission hole transmits an internal cavity pressure of the first working cylinder to an inner side of the valve flap.

[0014] In a preferred embodiment provided by the present application, a material of the valve flap is rubber.

[0015] In a preferred embodiment provided by the present application, an arc-shaped elastic framework is arranged on the inner side of the valve flap, and upper and lower ends of the elastic framework are in abutment with the outer wall of the first working cylinder.

[0016] In a preferred embodiment provided by the present application, the valve flap is fixedly connected with the elastic framework in a vulcanization manner.

[0017] In a preferred embodiment provided by the present application, the first through hole and / or the second through hole is configured as a slit.

[0018] In a preferred embodiment provided by the present application, the first working cylinder comprises a first cylinder body and a second cylinder body, an outer diameter of the second cylinder body is greater than an outer diameter of the first cylinder body, the second working cylinder is gap-set outside the first cylinder body, and an end face of the second working cylinder is in axial sealing abutment with the second cylinder body.

[0019] In a preferred embodiment provided by the present application, an upper joint is arranged on an end of the second working cylinder away from the second cylinder body.

[0020] According to the present application, a construction process is also provided, comprising the following steps:

[0021] The sand prevention regulating valve provided by the application is connected to the oil pipe and is connected to the water-flooded section of the well;

[0022] The pipe is inserted into the oil pipe to the water-flooded section;

[0023] Gas is injected into the annulus between the pipe and the oil pipe or into the pipe to carry out the drainage gas recovery.

[0024] Compared with the prior art, the application has the following advantages:

[0025] The first working cylinder, the second working cylinder and the switch valve are provided, in the initial state, the switch valve seals the second through hole on the second working cylinder, so that the fluid outside the sand prevention regulating valve cannot enter the inside of the sand prevention regulating valve, in the working state, the pressure outside the sand prevention regulating valve is transmitted to the switch valve through the second through hole, so that the switch valve is opened, so that the fluid outside the sand prevention regulating valve can enter the inside of the sand prevention regulating valve through the second through hole and the first through hole.

[0026] The first through hole and / or the second through hole are configured as slits, which can play a role of sand prevention and filtration. BRIEF DESCRIPTION OF DRAWINGS

[0027] The application will be described below with reference to the drawings.

[0028] Figure 1 An initial state of an embodiment of the sand prevention regulating valve according to the application is shown in the schematic view;

[0029] Figure 2 An enlarged schematic view of part A in the figure is shown; Figure 1

[0030] Figure 3 A working state of an embodiment of the sand prevention regulating valve according to the application is shown in the schematic view;

[0031] Figure 4 An enlarged schematic view of part B in the figure is shown; Figure 3

[0032] An enlarged schematic view of part B in the figure is shown; Figure 5

[0033] Figure 6 A structural schematic view of an embodiment of the sand prevention regulating valve according to the application is shown.

[0034] In the figure:

[0035] 1, first working cylinder; 11, first through hole; 12, pressure transmission hole; 13, first cylinder body; 14, second cylinder body;

[0036] ​​2. Second working cylinder; 21. Second through hole;

[0037] 3. Circular space;

[0038] 4. Switch valve; 41. Valve disc; 42. Elastic frame;

[0039] 5. Connect the connector;

[0040] 81. Oil pipe; 82. Pipeline;

[0041] 10. Shaft;

[0042] 100. Sand control valve.

[0043] In this application, all drawings are schematic and are used only to illustrate the principles of the invention, and are not drawn to scale. Detailed Implementation

[0044] The invention will now be described with reference to the accompanying drawings.

[0045] It should be noted that in this application, the direction near the wellhead after the well is entered according to the present invention is described as "up," "forward," or similar terms, that is... Figure 1 Above; the direction away from the wellhead after the well is entered according to the present invention is described as "below", "after" or similar terms, i.e. Figure 1 Below. These are not used to define the absolute position of the components involved, but can vary depending on the specific circumstances.

[0046] Figure 1 The structure of the sand-control regulating valve 100 according to the present invention is shown. For example... Figure 1 As shown, the sand control regulating valve 100 includes a first working cylinder 1, a second working cylinder 2, and a switching valve 4.

[0047] The first working cylinder 1 is generally cylindrical in shape, and at least one first through hole 11 is provided on the cylinder wall of the first working cylinder 1, which connects the outer side of the first working cylinder 1 with the inner cavity of the first working cylinder 1.

[0048] The second working cylinder 2 is generally cylindrical in shape. At least one second through hole 21 is provided on the cylinder wall of the second working cylinder 2, connecting the outer side of the second working cylinder 2 to its inner cavity. The second working cylinder 2 is intermittently and fixedly sleeved on the outer side of the first working cylinder 1, thereby forming an annular space 3 between the first working cylinder 1 and the second working cylinder 2. Both axial ends of the annular space 3 are closed, meaning that the upper and lower ends of the first working cylinder 1 and the second working cylinder 2 are fixed together by a sealed connection.

[0049] The first through hole 11 of the first working cylinder 1 and the second through hole 21 of the second working cylinder 2 are axially offset. Specifically, in this embodiment, as shown... Figure 1 As shown, the first through hole 11 is located at the upper part of the first working cylinder 1, and the second through hole 21 is located at the lower part of the second working cylinder 2, with the first through hole 11 located above the second through hole 21.

[0050] It is easy to understand that although the first through hole 11 in this embodiment is located above the second through hole 21, this is not intended to limit the scope of protection of the present invention. The first through hole 11 can also be located below the second through hole 21, as long as the first through hole 11 and the second through hole 21 are offset in the axial direction so that the switching valve 4 can perform the switching function.

[0051] The switching valve 4 is located within the annular space 3. In the initial state, as... Figure 1 and Figure 2 As shown, the switching valve 4 closes the channel between the first through hole 11 and the second through hole 21 (i.e., the annular space 3 between the first through hole 11 and the second through hole 21), thereby preventing fluid outside the sand control valve 100 from entering the interior of the sand control valve 100 through the first through hole 11 and the second through hole 21. In the working state, as... Figure 3 and Figure 4 As shown, the switch valve 4 opens the channel between the first through hole 11 and the second through hole 21. At this time, the fluid outside the sand control valve 100 can enter the annular space 3 through the second through hole 21, and then enter the interior of the sand control valve 100 through the first through hole 11.

[0052] In a specific embodiment, such as Figure 1 and Figure 2 As shown, the switching valve 4 includes an arc-shaped valve disc 41. Both the upper and lower ends of the valve disc 41 contact the outer wall of the first working cylinder 1. The middle part of the valve disc 41 abuts against the second working cylinder 2 and blocks the second through hole 21. The first through hole 11 is located outside the length range of the valve disc 41. Specifically, in this embodiment, the first through hole 11 is located above the valve disc 41. With this configuration, when the pressure on the outside of the sand control valve 100 increases, the pressure can be transmitted to the middle part of the valve disc 41 through the second through hole 21. When the pressure is sufficiently high, the middle part of the valve disc 41 will contract inward under the pressure, allowing the fluid outside the sand control valve 100 to enter the annular space 3 through the second through hole 21, and then enter the interior of the first working cylinder 1 from within the annular space 3 through the first through hole 11.

[0053] In this embodiment, multiple first through holes 11 are evenly distributed along the circumferential direction on the first working cylinder 1, and multiple second through holes 21 are evenly distributed along the circumferential direction on the second working cylinder 2. The first through holes 11 and / or the second through holes 21 are constructed as slits, that is, the first through holes 11 and / or the second through holes 21 are constructed as rectangular slits extending along the axial direction. This arrangement can play a role in sand filtering. Preferably, the width of the slits is in the range of 0.1 to 0.2 mm. When the second through holes 21 are constructed as slits, they can better seal with the valve disc 41, improving the reliability of the valve disc 41.

[0054] In a preferred embodiment, both the upper and lower ends of the valve disc 41 are sealed and abut against the first working cylinder 1, thereby forming a sealed space between the valve disc 41 and the first working cylinder 1. A pressure-transmitting hole 12 is provided on the cylinder wall of the first working cylinder 1, and the pressure-transmitting hole 12 is located at the position corresponding to the valve disc 41. That is, the pressure-transmitting hole 12 connects the sealed space between the valve disc 41 and the first working cylinder 1 with the inner cavity of the first working cylinder 1. With this configuration, when the pressure inside the first working cylinder 1 increases, the pressure inside the first working cylinder 1 can be transmitted to the inner side of the valve disc 41 through the pressure-transmitting hole 12, thereby causing the valve disc 41 to expand radially outward, strengthening the seal of the valve disc 41 against the second through hole 21. Furthermore, the provision of the pressure-transmitting hole 12 facilitates the application of the construction process of this invention, as detailed below.

[0055] In one specific embodiment, the valve disc 41 is made of rubber, such as nitrile rubber, hydrogenated nitrile rubber, or fluororubber. An arc-shaped elastic frame 42 is provided on the inner side of the valve disc 41, with both its upper and lower ends abutting against the outer wall of the first working cylinder 1. The elastic frame 42 increases the support for the valve disc 41, further enhancing its pre-tightening force. In the initial state, under the elastic force of the elastic frame 42, the valve disc 41 is tightly fitted against the inner wall of the second working cylinder 2, forming a seal against the second through hole 21.

[0056] In one specific embodiment, the valve disc 41 is fixedly connected to the elastic skeleton 42 by vulcanization.

[0057] In one specific embodiment, the first working cylinder 1 includes a first cylinder body 13 and a second cylinder body 14 coaxially fixedly connected. The second cylinder body 14 is disposed at the lower end of the first cylinder body 13, and the outer diameter of the second cylinder body 14 is larger than the outer diameter of the first cylinder body 13. The second working cylinder 2 is intermittently sleeved on the outside of the first cylinder body 13. The upper end of the second working cylinder 2 is fixedly connected to the first cylinder body 13 by a threaded connection and is provided with a sealing ring. The upper end of the second working cylinder 2 is flush with the upper end of the first cylinder body 13, and the lower end face of the second working cylinder 2 is in sealing contact with the upper end face of the second cylinder body 14, thereby sealing both ends of the annular space 3 axially.

[0058] Furthermore, the lower end of the second cylinder 14 is configured as a connector that can be connected to an oil pipe, and the upper end of the second working cylinder 2 is fixedly provided with an upper connector 5 that can be connected to an oil pipe by means of a threaded connection. A sealing ring is provided between the upper connector 5 and the second working cylinder 2.

[0059] According to the present invention, a construction process is also provided, comprising the following steps:

[0060] The sand control valve 100 provided according to the present invention is connected to the tubing 81 and inserted into the well to the water-flooded section;

[0061] Insert pipe 82 into oil pipe 81 to the water-flooded section;

[0062] Gas is injected into the annulus between pipe 82 and oil pipe 81 or into pipe 82 to perform drainage and gas extraction.

[0063] In a specific embodiment, such as Figure 5 As shown, at least one sand control valve 100 is first connected in series to the tubing 81 and lowered into the vertical or horizontal section of the well that is flooded. At this time, the bottom end of the tubing 81 is blocked. Then, a pipe 82 (usually a small-sized continuous tubing) is lowered into the tubing 81. The pipe 82 is inserted into the bottom end of the tubing 81, and the bottom end of the pipe 82 is open.

[0064] When the formation energy is sufficient, under the action of formation energy (formation pressure, natural gas pressure, etc.), the valve disc 41 of the sand control regulating valve 100 contracts radially inward under the action of formation pressure, thereby connecting the second through hole 21 and the first through hole 11. The accumulated liquid in the large annulus between the tubing 81 and the wellbore 10 is squeezed into the small annulus between the tubing 81 and the pipe 82 and into the pipe 82 through the second through hole 21, the annular space 3 and the first through hole 11 in sequence. Formation compressed gas (natural gas, etc.) enters together and moves towards the surface along the tubing 81. During the movement, the natural gas expands in volume, continuously carrying the accumulated liquid to the surface, thereby achieving the effect of drainage and gas production.

[0065] When the formation energy is insufficient, the fluid in the large annulus between tubing 81 and wellbore 10 can open valve 41, allowing the fluid to enter the small annulus between tubing 81 and pipe 82 and into pipe 82. However, the energy is insufficient to transport the fluid along tubing 81 to the surface. In the above situation, when there is no fluid in tubing 81, the pressure of the fluid in the large annulus can open valve 41, allowing the fluid in the large annulus to enter tubing 81. As fluid continuously enters tubing 81, the pressure in the large annulus gradually decreases until it is insufficient to open valve 41. At this point, nitrogen, natural gas, or other gases are injected into pipeline 82 (or the small annulus between pipeline 82 and oil pipe 81) via a ground-based gas lift vehicle to pressurize it. Due to the pressure difference inside and outside pipeline 82, the liquid accumulated in oil pipe 81 will move from the small annulus between pipeline 82 and oil pipe 81 (or from pipeline 82) to the ground. The compressed gas expands in volume during the movement, continuously carrying the liquid accumulated in oil pipe 81 to the ground, thereby achieving the effect of drainage and gas extraction. When the liquid in the large annulus is replenished again to the point that it can push valve 41 to open, the above steps can be repeated.

[0066] Since the sand control regulating valve 100 of the present invention is provided with a pressure transmission hole 12 on the first working cylinder 1, when nitrogen, natural gas or other gases are injected into the pipeline 82 (or the small annulus between the pipeline 82 and the oil pipe 81) by the ground air lift vehicle for pressurization, the pressure inside the first working cylinder 1 increases, which can apply a pressure to the valve disc 41, and avoid the formation pressure (liquid in the large annulus) from being replenished too quickly during this process, causing the valve disc 41 to open prematurely, thereby making the construction process provided by the present invention more reliable.

[0067] In the description of this invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0068] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0069] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0070] Finally, it should be noted that the above description is merely a preferred embodiment of the present invention and does not constitute any limitation on the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A sand-proof regulating valve, characterized in that, include: The first working cylinder (1) has at least one first through hole (11) on its cylinder wall; A second working cylinder (2) is intermittently sleeved outside the first working cylinder (1), forming an annular space (3) between the first working cylinder (1) and the second working cylinder (2). The annular space (3) is closed at both axial ends, and at least one second through hole (21) is provided on the cylinder wall of the second working cylinder (2); and A switching valve (4) is disposed in the annular space (3). The switching valve (4) is configured to close the channel between the first through hole (11) and the second through hole (21) in the initial state, and to open the channel between the first through hole (11) and the second through hole (21) in the working state.

2. The sand-control regulating valve according to claim 1, characterized in that, The switching valve (4) includes an arc-shaped valve disc (41), the upper and lower ends of which are in contact with the outer wall of the first working cylinder (1), and the middle part of the valve disc (41) abuts against the second working cylinder (2) and blocks the second through hole (21).

3. The sand-control regulating valve according to claim 2, characterized in that, Both the upper and lower ends of the valve disc (41) are sealed and abutted against the first working cylinder (1).

4. The sand-control regulating valve according to claim 3, characterized in that, A pressure transmission hole (12) is provided on the cylinder wall of the first working cylinder (1), and the pressure transmission hole (12) transmits the internal pressure of the first working cylinder (1) to the inside of the valve disc (41).

5. The sand-control regulating valve according to claim 4, characterized in that, The valve disc (41) is made of rubber.

6. The sand-control regulating valve according to claim 5, characterized in that, An arc-shaped elastic frame (42) is provided on the inner side of the valve disc (41), and both the upper and lower ends of the elastic frame (42) abut against the outer wall of the first working cylinder (1).

7. The sand-control regulating valve according to claim 6, characterized in that, The valve disc (41) is fixedly connected to the elastic skeleton (42) by vulcanization.

8. The sand-control regulating valve according to any one of claims 1 to 7, characterized in that, The first through hole (11) and / or the second through hole (21) are constructed as slits.

9. The sand-control regulating valve according to any one of claims 1 to 7, characterized in that, The first working cylinder (1) includes a first cylinder body (13) and a second cylinder body (14). The outer diameter of the second cylinder body (14) is larger than the outer diameter of the first cylinder body (13). The second working cylinder (2) is intermittently sleeved on the outside of the first cylinder body (13). The end face of the second working cylinder (2) is axially sealed and abutted against the second cylinder body (14).

10. A construction process, characterized in that, Connect the sand control valve according to any one of claims 1 to 9 to the tubing and insert it into the well to the water-flooded section; Insert a pipe into the oil pipe to the flooded section; Gas is injected into the annulus between the pipeline and the oil pipe, or into the pipeline, to perform drainage and gas extraction.

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