Pressure-adjustable small-hole check valve

Abstract

The pressure-adjustable small-hole check valve comprises a valve body, the valve body comprises a first cavity and a second cavity, the first cavity is located at the liquid inlet end, the second cavity is located at the liquid outlet end, the longitudinal section of the first cavity is in a trapezoid shape, a large opening of the first cavity is located at the liquid inlet, and the first cavity is in conical fit with a pressing cap; the pressing cap is provided with a liquid flow channel along the axis of the pressing cap, and the liquid flow channel is communicated with the first cavity; a base is arranged in the second cavity and is a hollow cylinder, the base is in threaded connection with the valve body, a compression rod is sleeved with the base, and an elastic ring is arranged between the base and the compression rod. The pressure-adjustable small-hole check valve is installed on the central pipe wall of a rubber sleeve cavity, due to the fact that an elastic ring can be replaced, the pressure can be adjusted, an expanding type packer rubber sleeve cannot retract after expanding, the permanent packing function of a packer is achieved, and the purposes of greatly reducing operation cost and improving efficiency are achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of fracturing tools and relates to a pressure-adjustable small-hole check valve. Background Art

[0002] At present, there are many low-liquid and low-yield wells in oil fields, and the number is increasing every year. In order to further increase the production of single wells, it is necessary to carry out repeated transformation of old wells. In the field process application of repeated transformation of old wells, the transformation processes currently used mainly include double-seal single-card drag fracturing and reconstructed wellbore perforation fracturing, but these two fracturing transformation methods cannot be permanently sealed, resulting in low construction efficiency and high operating costs. Summary of the invention

[0003] The purpose of the present invention is to provide a pressure-adjustable small-hole check valve, which solves the problem that the seal cannot be permanently set in the two main processes of repeated transformation of double-seal single-card drag fracturing and reconstructed wellbore perforation fracturing.

[0004] The technical solution adopted by the present invention is that the pressure-adjustable small-hole check valve includes a valve body, the valve body includes a first cavity and a second cavity, the first cavity is located at the liquid inlet end, the second cavity is located at the liquid outlet end, the longitudinal section of the first cavity is trapezoidal, the larger opening of the first cavity is located at the liquid inlet, the first cavity is conically matched with a pressure cap, the pressure cap is provided with a liquid flow channel along its axis, and the liquid flow channel is connected with the first cavity;

[0005] The second cavity has a base, which is a hollow cylinder, and is threadedly connected to the valve body. A compression rod is sleeved inside the base, and an elastic ring is arranged between the base and the compression rod.

[0006] The present invention is also characterized in that:

[0007] The outer wall of the valve body is provided with a plurality of through holes, and the outer wall of the base is provided with a plurality of blind holes corresponding to the positions of the through holes, and each pair of through holes and blind holes is provided with a top screw;

[0008] A shaft shoulder is provided at one end of the compression rod close to the first cavity, and a sealing gasket is provided between the end surface of the shaft shoulder close to the first cavity and the valve body;

[0009] The third step transition fit between the base and the compression rod;

[0010] The fourth step of the base and the compression rod is clearance-matched;

[0011] The outer wall of the liquid inlet end of the valve body is provided with a plurality of annular grooves, which are evenly distributed;

[0012] The elastic ring is fixed on a base corresponding to the fourth step.

[0013] The beneficial effects of the present invention are:

[0014] The present invention provides a pressure-adjustable small-hole check valve, which is installed on the central pipe wall of the rubber tube cavity. Since the elastic ring is replaceable, the pressure can be adjusted, so that the rubber tube of the expandable packer cannot be retracted after expansion, thereby realizing the permanent sealing function of the packer, thereby achieving the purpose of greatly reducing operating costs and improving efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a structural schematic diagram of a pressure-adjustable small-hole check valve of the present invention;

[0016] Figure 2 It is a schematic diagram of the compression rod structure of a pressure-adjustable small-hole check valve of the present invention;

[0017] In the figure, 1. pressure cap, 2. valve body, 3. compression rod, 4. end face sealing gasket, 5. elastic ring, 6. base, 7. liquid flow channel, 8. first cavity, 9. second cavity, 10. through hole, 11. blind hole, 12. top screw, 13. first step, 14. second step, 15. third step, 16. fourth step. DETAILED DESCRIPTION

[0018] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0019] The present invention provides a pressure-adjustable small-hole check valve, such as Figure 1 As shown, the valve body 2 includes a first cavity 8 and a second cavity 9. The first cavity 8 is located at the liquid inlet end, and the second cavity 9 is located at the liquid outlet end. The longitudinal section of the first cavity 8 is trapezoidal, and the larger opening of the first cavity 8 is located at the liquid inlet. The first cavity 8 is conically matched with a pressure cap 1. The pressure cap 1 is provided with a liquid flow channel 7 along its axis, and the liquid flow channel 7 is connected with the first cavity 8.

[0020] The second cavity 9 has a base 6 in it. The base 6 is a hollow cylinder. The base 6 is threadedly connected to the valve body 2 . A compression rod 3 is sleeved inside the base 6 . An elastic ring 5 is provided between the base 6 and the compression rod 3 .

[0021] The outer wall of the valve body 2 is provided with a plurality of through holes 10 , and the outer wall of the base 6 is provided with a plurality of blind holes 11 corresponding to the positions of the through holes 10 . A top screw 12 is provided in each pair of the through holes 10 and the blind holes 11 .

[0022] like Figure 2 As shown, the compression rod 3 is a stepped cylinder, and a shoulder is provided at one end of the compression rod 3 close to the first cavity 8. A sealing gasket 4 is provided between the end surface of the shoulder close to the first cavity 8 and the valve body 2 to form an end surface seal.

[0023] The base 6 and the third step of the compression rod 3 are transitionally matched, and the base 6 and the fourth step of the compression rod 3 are clearance matched.

[0024] The outer wall of the liquid inlet end of the valve body 2 is provided with a plurality of annular grooves which are evenly distributed. When the pressure cap 1 is pressed into the valve body 2, the valve body 2 undergoes plastic deformation, and the outer ridges and grooves "bite into" the inner wall of the mounting hole to form a plurality of sealing layers, thereby achieving a reliable sealing effect.

[0025] The elastic ring 5 is fixed on the base 6 corresponding to the fourth step 16 , and the elastic ring 5 can be replaced according to the pressure, thereby achieving adjustable pressure.

[0026] The present invention is a pressure-adjustable small-hole check valve, and its working principle is as follows:

[0027] like Figure 1 As shown, the adjustable small-hole check valve comprises a pressing cap 1, a valve body 2, a compression rod 3, a sealing gasket 4, an elastic ring 5, a base 6, a liquid flow channel 7, a first cavity 8, a second cavity 9, a through hole 10, a blind hole 11, and a top screw 12, wherein the joints between the pressing cap 1 and the valve body 2 are of conical design, and the outer edge of the valve body 2 has a "ridge" and a "groove" structure. During installation, since the pressing cap 1 and the valve body 2 are conically matched, in the process of pressing the pressing cap 1 into the valve body 2, the valve body 2 undergoes plastic deformation, and the outer ridges and grooves "bite into" the inner wall of the installation hole to form multiple sealing layers, thereby achieving a reliable sealing effect.

[0028] A liquid flow channel 7 is designed on the pressure cap 1. When the liquid enters the valve body 2 from the pressure cap 1, due to the increase in hydraulic pressure, when the preset value of the elastic ring 5 is reached, the compression rod 3 is pushed open, and the liquid enters the expansion packer rubber cylinder, and the expansion packer is gradually set. After the expansion packer is set, the wellbore pump is stopped, the pressure in the adjustable small hole check valve disappears, and the compression rod 3 is reset under the action of the reset force of the elastic ring 5, the small hole liquid inlet channel is closed, and the sealing gasket 4 seals the compression rod 3 at the end face, thereby realizing the permanent setting of the packer. In the mechanism of the one-way valve, the compression rod 3 and the base 6 are clearance-matched, and the elastic ring 5 is fixed on the base 6. The elastic ring 5 is replaceable, so that the pressure of the liquid entering the liquid flow channel 7 can be adjusted, and the pressure can be adjusted. A sealing gasket 4 is matched between the first step surface 13 of the compression rod 3 and the valve body to form an end face seal to prevent liquid from entering or flowing out from the matching surface, thereby realizing the functional permanent setting.

[0029] Example 1

[0030] like Figure 1 As shown, a pressure-adjustable small-hole check valve proposed in this embodiment includes a valve body 2, the valve body 2 includes a first cavity 8 and a second cavity 9, the first cavity 8 is located at the liquid inlet end, the second cavity 9 is located at the liquid outlet end, the longitudinal section of the first cavity 8 is trapezoidal, the larger opening of the first cavity 8 is located at the liquid inlet, the first cavity 8 is conically matched with a pressure cap 1, the pressure cap 1 is provided with a liquid flow channel 7 along its axis, and the liquid flow channel 7 is connected with the first cavity 8;

[0031] The second cavity 9 has a base 6 in it. The base 6 is a hollow cylinder. The base 6 is threadedly connected to the valve body 2 . A compression rod 3 is sleeved inside the base 6 . An elastic ring 5 is provided between the base 6 and the compression rod 3 .

[0032] Example 2

[0033] like Figure 1 As shown, a pressure-adjustable small-hole check valve proposed in this embodiment includes a valve body 2, the valve body 2 includes a first cavity 8 and a second cavity 9, the first cavity 8 is located at the liquid inlet end, the second cavity 9 is located at the liquid outlet end, the longitudinal section of the first cavity 8 is trapezoidal, the larger opening of the first cavity 8 is located at the liquid inlet, the first cavity 8 is conically matched with a pressure cap 1, the pressure cap 1 is provided with a liquid flow channel 7 along its axis, and the liquid flow channel 7 is connected with the first cavity 8;

[0034] The second cavity 9 has a base 6 in it. The base 6 is a hollow cylinder. The base 6 is threadedly connected to the valve body 2 . A compression rod 3 is sleeved inside the base 6 . An elastic ring 5 is provided between the base 6 and the compression rod 3 .

[0035] The outer wall of the valve body 2 is provided with a plurality of through holes 10 , and the outer wall of the base 6 is provided with a plurality of blind holes 11 corresponding to the positions of the through holes 10 . A top screw 12 is provided in each pair of the through holes 10 and the blind holes 11 .

[0036] Example 3

[0037] like Figure 1 As shown, a pressure-adjustable small-hole check valve proposed in this embodiment includes a valve body 2, the valve body 2 includes a first cavity 8 and a second cavity 9, the first cavity 8 is located at the liquid inlet end, the second cavity 9 is located at the liquid outlet end, the longitudinal section of the first cavity 8 is trapezoidal, the larger opening of the first cavity 8 is located at the liquid inlet, the first cavity 8 is conically matched with a pressure cap 1, the pressure cap 1 is provided with a liquid flow channel 7 along its axis, and the liquid flow channel 7 is connected with the first cavity 8;

[0038] The second cavity 9 has a base 6 in it. The base 6 is a hollow cylinder. The base 6 is threadedly connected to the valve body 2 . A compression rod 3 is sleeved inside the base 6 . An elastic ring 5 is provided between the base 6 and the compression rod 3 .

[0039] The outer wall of the valve body 2 is provided with a plurality of through holes 10 , and the outer wall of the base 6 is provided with a plurality of blind holes 11 corresponding to the positions of the through holes 10 . A top screw 12 is provided in each pair of the through holes 10 and the blind holes 11 .

[0040] A shaft shoulder is provided at one end of the compression rod 3 close to the first cavity 8 , and a sealing gasket 4 is provided between the end surface of the shaft shoulder close to the first cavity 8 and the valve body 2 .

[0041] Example 4

[0042] like Figure 1As shown, a pressure-adjustable small-hole check valve proposed in this embodiment includes a valve body 2, the valve body 2 includes a first cavity 8 and a second cavity 9, the first cavity 8 is located at the liquid inlet end, the second cavity 9 is located at the liquid outlet end, the longitudinal section of the first cavity 8 is trapezoidal, the larger opening of the first cavity 8 is located at the liquid inlet, the first cavity 8 is conically matched with a pressure cap 1, the pressure cap 1 is provided with a liquid flow channel 7 along its axis, and the liquid flow channel 7 is connected with the first cavity 8;

[0043] The second cavity 9 has a base 6 in it. The base 6 is a hollow cylinder. The base 6 is threadedly connected to the valve body 2 . A compression rod 3 is sleeved inside the base 6 . An elastic ring 5 is provided between the base 6 and the compression rod 3 .

[0044] The outer wall of the valve body 2 is provided with a plurality of through holes 10 , and the outer wall of the base 6 is provided with a plurality of blind holes 11 corresponding to the positions of the through holes 10 . A top screw 12 is provided in each pair of the through holes 10 and the blind holes 11 .

[0045] A shaft shoulder is provided at one end of the compression rod 3 close to the first cavity 8 , and a sealing gasket 4 is provided between the end surface of the shaft shoulder close to the first cavity 8 and the valve body 2 .

[0046] The base 6 is transitionally matched with the third step 15 of the compression rod 3 , and the base 6 is clearance matched with the fourth step 16 of the compression rod 3 .

Claims

1. Pressure adjustable small hole check valve, characterized in that: The valve body (2) comprises a first cavity (8) and a second cavity (9), wherein the first cavity (8) is located at the liquid inlet end, and the second cavity (9) is located at the liquid outlet end, the longitudinal section of the first cavity (8) is trapezoidal, the larger opening of the first cavity (8) is located at the liquid inlet, the first cavity (8) is conically matched with a pressure cap (1), the pressure cap (1) is provided with a liquid flow channel (7) along its axis, and the liquid flow channel (7) is connected with the first cavity (8); The second cavity (9) has a base (6) in it. The base (6) is a hollow cylinder. The base (6) is threadedly connected to the valve body (2). A compression rod (3) is sleeved inside the base (6). An elastic ring (5) is provided between the base (6) and the compression rod (3).

2. The pressure-adjustable small-hole check valve according to claim 1, characterized in that: The outer wall of the valve body (2) is provided with a plurality of through holes (10), the outer wall of the base (6) is provided with a plurality of blind holes (11) corresponding to the positions of the through holes (10), and each pair of the through holes (10) and the blind holes (11) is provided with a top screw (12).

3. The pressure-adjustable small-hole check valve according to claim 1, characterized in that: A shaft shoulder is provided at one end of the compression rod (3) close to the first cavity (8), and a sealing gasket (4) is provided between the end surface of the shaft shoulder close to the first cavity (8) and the valve body (2).

4. The pressure-adjustable small-hole check valve according to claim 1, characterized in that: The base (6) is transitionally matched with the third step (15) of the compression rod (3).

5. The pressure-adjustable small-hole check valve according to claim 1, characterized in that: The base (6) is clearance-matched with the fourth step (16) of the compression rod (3).

6. The pressure-adjustable small-hole check valve according to claim 1, characterized in that: The outer wall of the liquid inlet end of the valve body (2) is provided with a plurality of annular grooves, and the annular grooves are distributed at equal intervals.

7. The pressure-adjustable small-hole check valve according to claim 1, characterized in that: The elastic ring (5) is fixed on the base (6) corresponding to the fourth step (16) of the compression rod (3).

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