Bidirectional well killing valve

Abstract

The bidirectional well killing valve comprises an upper connector, a circulating channel is formed in the center of the upper connector, two ball chambers are symmetrically arranged on the outer wall of the upper connector, ball valves are arranged in the two ball chambers correspondingly, the ball valves are connected with the top walls of the ball chambers through springs, and the two ball chambers communicate with the circulating channel through first circulating holes correspondingly; the lower ends of the two ball chambers are respectively communicated with an L-shaped circulating hole, the outer wall of the upper connector is respectively provided with a sliding groove which is perpendicular to and communicated with the transverse part of the L-shaped circulating hole, a sliding sleeve is arranged in the sliding groove, the upper connector is provided with a rupture disk hole communicated with the sliding groove, a rupture disk is arranged in the rupture disk hole and connected with the sliding sleeve, and the L-shaped circulating hole and the rupture disk hole penetrate through the outer wall of the upper connector. The bidirectional well killing device is simple in structure and reasonable in design, the forward and reverse bidirectional well killing function can be achieved, the problems of reservoir pollution, unstable well pressure and the like caused by squeezing and injection method well killing on a shaft at the bottom of a packer in the prior art are solved, and the well control risk is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of oilfield operation auxiliary devices and relates to a two-way well killing valve. Background Art

[0002] At present, affected by many factors such as the multiple pressure systems of the formation during drilling, most high-temperature and high-pressure deep wells have a wellbore structure with a 7-inch hanging 5-inch (or 41 / 2-inch) casing. The hanging length of the 5-inch (or 41 / 2-inch) casing varies from 500 to 1500m. When conducting testing, fracturing and other operations in this wellbore structure, the tool seals are restricted by high temperature and high pressure, and the packer is mostly sealed in the upper 7-inch casing. Before the tubing is unsealed, the reverse circulation valve on the upper part of the packer is required to perform well pressure control. However, for the wellbore below the packer, only the squeezing method can be used for well pressure control. Since the tubing hanging below the packer is long, the squeezing method is not ideal for well pressure control and is very easy to contaminate the reservoir. There is also a well control risk of unstable well pressure, which brings safety hazards to the subsequent tubing operation. Summary of the Invention

[0003] The purpose of the present invention is to provide a two-way well-killing valve, which solves the problem that when the tail pipe hanging at the bottom of the high-temperature and high-pressure deep well packer is long, the squeezing method well-killing effect is not ideal, the reservoir is easily contaminated, and the well pressure is unstable.

[0004] The technical solution adopted by the present invention is a two-way well killing valve, comprising an upper joint, a circulation channel is opened at the center of the upper joint, two ball chambers are symmetrically provided on the outer wall of the upper joint, and ball valves are respectively provided in the two ball chambers, and the ball valves are connected to the top wall of the ball chamber through springs;

[0005] The two ball chambers are connected to the circulation channel through the first circulation hole respectively. The lower ends of the two ball chambers are connected to L-shaped circulation holes respectively. The outer wall of the upper joint is provided with a sliding groove perpendicular to and connected to the horizontal part of the L-shaped circulation hole. A sliding sleeve is provided in the sliding groove. A rupture disk hole connected to the sliding groove is opened on the upper joint. A rupture disk is provided in the rupture disk hole, and the rupture disk is connected to the sliding sleeve. The L-shaped circulation hole and the rupture disk hole pass through the outer wall of the upper joint.

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

[0007] The two ball chambers and chutes are arranged along the length of the upper joint;

[0008] A through hole is opened in the center of the sleeve, and the distance from the center line of the through hole to the center line of the horizontal part of the L-shaped circulation hole is equal to the distance from the lower end of the sleeve to the lower end of the slide groove;

[0009] The lower part of the sliding sleeve is connected to the outer wall of the upper joint through a shear pin, which is located below the L-shaped circulation hole;

[0010] The lower ends of the two ball chambers are respectively provided with ball seats, and the ball valves are arranged on the ball seats;

[0011] The included angle between the first circulation hole and the circulation channel is 45 degrees.

[0012] The beneficial effects of the present invention are:

[0013] The present invention has a simple structure and reasonable design, and can realize the functions of forward and reverse bidirectional well killing. In the wellbore structure with 7" hanging 5" (or 41 / 2") casing, the tail pipe hanging at the bottom of the packer is relatively long (ranging from 500 to 1200m). Through this tool, the wellbore part above the packer is first subjected to reverse circulation well killing; after the wellhead is replaced and the packer is unsealed, the entire wellbore is subjected to positive circulation well killing, which solves the problems of reservoir contamination and unstable well pressure caused by the squeeze injection method for well killing at the bottom of the packer in the existing technical solution, and reduces the well control risk. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a schematic diagram of the structure of the bidirectional well-killing valve of the present invention;

[0015] Figure 2 It is a schematic diagram of the sliding sleeve structure of the present invention.

[0016] Markings in the figure: 1. Upper joint, 2. Circulation channel, 3. Spring, 4. First circulation hole, 5. Ball chamber, 6. Ball valve, 7. Ball seat, 8. Rupture disk hole, 9. Sleeve, 10. Through hole, 11. L-shaped circulation hole, 12. Slide groove, 13. Shear pin. DETAILED DESCRIPTION

[0017] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0018] Two-way well killing valve, such as Figure 1 As shown, it includes an upper joint 1, a circulation channel 2 is opened at the center of the upper joint 1, which allows fluid to flow through, and two ball chambers 5 are symmetrically provided on the outer wall of the upper joint 1, wherein the two ball chambers 5 are arranged along the length of the upper joint 1, and a ball valve 6 is respectively provided in the two ball chambers 5. The ball valve 6 is connected to the top wall of the ball chamber 5 through a spring 3. The lower ends of the two ball chambers 5 are respectively provided with a ball seat 7, and the ball valve 6 is arranged on the ball seat 7. The ball valve 6 can move up and down under the action of the spring 3 to realize forward and reverse flow of the fluid, thereby realizing forward and reverse well killing operation;

[0019] like Figure 1As shown, the two ball chambers 5 are respectively connected to the circulation channel 2 through the first circulation hole 4. Specifically, the angle between the first circulation hole 4 and the circulation channel 2 is 45 degrees, which better ensures the flow of fluid. The lower ends of the two ball chambers 5 are respectively connected with L-shaped circulation holes 11, and the L-shaped circulation hole 11 is connected to the annulus outside the upper joint 1. The outer wall of the upper joint 1 is respectively provided with a chute 12 connected to the L-shaped circulation hole 11. The chute 12 is perpendicular to the horizontal part of the L-shaped circulation hole 11, that is, the two chute 12 are arranged along the length of the upper joint 1, and a sliding sleeve 9 is provided in the chute 12. The upper joint 1 is provided with a rupture disk hole 8 connected to the chute 12, and the rupture disk hole 8 is connected to the annulus outside the upper joint 1. The rupture disk hole 8 is connected to each other, and a rupture disk is provided in the rupture disk hole 8, which is connected to the sliding sleeve 9. When in use, the annulus is pressurized to rupture the rupture disk, and the annular space fluid enters the chute 12 along the rupture disk hole 8, thereby pushing the sliding sleeve 9 downward. The lower part of the sliding sleeve 9 is connected to the outer wall of the upper joint 1 through the shear pin 13. The shear pin 13 is located below the L-shaped circulation hole 11. On the one hand, the shear pin 13 can fix the sliding sleeve 9. On the other hand, after the fluid enters the L-shaped circulation hole 11, the shear pin 13 can block the fluid from flowing downward, ensuring that the fluid flows upward and enters the space above the L-shaped circulation hole 11, giving the sliding sleeve 9 downward pressure. The shear pin 13 is sheared under the action of pressure, and the sliding sleeve 9 moves downward.

[0020] Further, such as Figure 2 As shown, a through hole 10 is opened in the center of the sliding sleeve 9. The distance from the center line of the through hole 10 to the center line of the horizontal part of the L-shaped circulation hole 11 is equal to the distance from the lower end of the sliding sleeve 9 to the lower end of the slide groove 12. This design ensures that when the sliding sleeve 9 slides down to the bottom of the slide groove 12, the through hole 10 on the sliding sleeve 9 is exactly on the same center line as the horizontal part of the L-shaped circulation hole 11, ensuring fluid flow.

[0021] Example 1

[0022] Before the tubing string is pulled out, the annulus is pressurized to rupture the rupture disk in the rupture disk hole 8. The annulus fluid flows along the rupture disk hole 8 into the chute 12 and into the space above it. The fluid exerts downward pressure on the sleeve 9, and the shear pin 13 is sheared off under the action of pressure. The sleeve 9 moves downward, so that the center line of the through hole 10 coincides with the center line of the horizontal part of the L-shaped circulation hole 11, so that the through hole 10 and the L-shaped circulation hole 11 form a circulation channel. The fluid flows into the ball chamber 5 through the L-shaped circulation hole 11, and the fluid pushes the ball valve 6 upward. Then the fluid enters the circulation channel 2 through the circulation hole 4 and returns to the wellhead, completing the preliminary backpressure well operation and achieving preliminary wellbore pressure on the wellbore above the packer. After the backpressure well is completed, it can be guaranteed that no blowout will occur in a short period of time. During this period, the wellhead can be replaced (disassembling the upper half of the oil production tree and installing the blowout preventer) and the packer can be unsealed.

[0023] Example 2

[0024] After the packer is unsealed, the killing fluid is injected from the oil pipe. The fluid enters the ball chamber 5 through the circulation channel 2 and the circulation hole 4. The fluid pushes the ball valve 6 downward to sit on the ball seat 7, closing the L-shaped circulation hole 11 channel connected to the oil casing. The killing fluid reaches the pipe pin through the circulation channel 2, completing the positive pressure well operation and achieving well killing of the entire wellbore.

[0025] Example 3

[0026] A two-way well-killing valve comprises an upper joint 1, a circulation channel 2 is provided at the center of the upper joint 1, two ball chambers 5 are symmetrically provided on the outer wall of the upper joint 1, the two ball chambers 5 are respectively connected to the circulation channel 2 through the first circulation hole 4, the lower ends of the two ball chambers 5 are respectively connected to an L-shaped circulation hole 11, a chute 12 connected to the L-shaped circulation hole 11 is respectively provided on the outer wall of the upper joint 1, the chute 12 is perpendicular to the horizontal part of the L-shaped circulation hole 11, a sliding sleeve 9 is provided in the chute 12, a rupture disk hole 8 is provided on the upper joint 1 and connected to the chute 12, and a rupture disk is provided in the rupture disk hole 8 The rupture disk is connected to the sliding sleeve 9, and a through hole 10 is opened in the center of the sliding sleeve 9. The distance from the center line of the through hole 10 to the center line of the horizontal part of the L-shaped circulation hole 11 is equal to the distance from the lower end of the sliding sleeve 9 to the lower end of the chute 12. When the back pressure is applied, the rupture disk is broken, and the sliding sleeve 9 gradually moves downward under the fluid pressure. The downward pressure cuts the shear pin 13, and the sliding sleeve 9 falls to the lower end of the chute 12. This design can just ensure that when the sliding sleeve 9 slides down to the bottom of the chute 12, the through hole 10 on the sliding sleeve 9 is exactly on the same center line as the horizontal part of the L-shaped circulation hole 11, ensuring the flow of fluid.

Claims

1. Two-way well-killing valve, characterized in that: It comprises an upper joint (1), a circulation channel (2) is provided at the center of the upper joint (1), two ball chambers (5) are symmetrically provided on the outer wall of the upper joint (1), ball valves (6) are respectively provided in the two ball chambers (5), and the ball valves (6) are connected to the top walls of the ball chambers (5) through springs (3); The two ball chambers (5) are respectively connected to the circulation channel (2) through the first circulation hole (4); the lower ends of the two ball chambers (5) are respectively connected to L-shaped circulation holes (11); the outer wall of the upper joint (1) is respectively provided with a slide groove (12) which is perpendicular to and connected to the transverse part of the L-shaped circulation hole (11); a sliding sleeve (9) is arranged in the slide groove (12); a rupture disk hole (8) connected to the slide groove (12) is opened on the upper joint (1); a rupture disk is arranged in the rupture disk hole (8); the rupture disk is connected to the sliding sleeve (9); the L-shaped circulation hole (11) and the rupture disk hole (8) pass through the outer wall of the upper joint (1).

2. The two-way well-killing valve according to claim 1, characterized in that: The two ball chambers (5) and the slide groove (12) are both arranged along the length direction of the upper joint (1).

3. The two-way well-killing valve according to claim 2, characterized in that: A through hole (10) is provided at the center of the sliding sleeve (9), and the distance from the center line of the through hole (10) to the center line of the transverse portion of the L-shaped circulation hole (11) is equal to the distance from the lower end of the sliding sleeve (9) to the lower end of the sliding groove (12).

4. The two-way well-killing valve according to claim 1, characterized in that: The lower part of the sliding sleeve (9) is connected to the outer wall of the upper joint (1) via a shear pin (13), and the shear pin (13) is located below the L-shaped circulation hole (11).

5. The two-way well-killing valve according to claim 1, characterized in that: The lower ends of the two ball chambers (5) are respectively provided with ball seats (7), and the ball valve (6) is arranged on the ball seats (7).

6. The two-way well-killing valve according to claim 1, characterized in that: The included angle between the first circulation hole (4) and the circulation channel (2) is 45 degrees.

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