A seal inspection device and seal inspection method for expansion type insert seal installation

Abstract

The present invention is a seal inspection device for installation of an expansion type insert seal and a seal inspection method thereof, the seal inspection device body comprises a ball seat outer sleeve, a ball seat nut is installed at the bottom of the ball seat outer sleeve, a center tube is installed at the top of the ball seat outer sleeve, a ball seat is installed in the ball seat outer sleeve through shear nails, a flow hole is provided on the side wall of the ball seat outer sleeve, an upper compression piston, a first sealing rubber tube, a seal inspection sleeve, a second sealing rubber tube and a lower compression piston are installed on the outer wall of the center tube from top to bottom, a first reset compression spring is provided between the corresponding upper compression pistons on the outside of the center tube, and a second reset compression spring is provided between the corresponding lower compression pistons, through holes are provided on the seal inspection sleeve and the center tube at the cavity, a seal inspection hole is provided at the part of the lower compression piston penetrating the cavity, and pressure transmission holes are provided in the center tube corresponding to the upper compression piston and the lower compression piston. The present invention can verify the damage of the downhole sealing tube itself to ensure that the expansion type insert seal can effectively achieve sealing and avoid unnecessary overhaul operations.

Description

Technical Field

[0001] The invention relates to the technical field of supporting equipment for oil and gas exploitation in the petroleum industry, and in particular to a sealing inspection device for installation of an expansion-type insert seal and a sealing inspection method thereof. Background Art

[0002] At present, the insert seals used in the oil industry are mostly traditional seal module insert seal structures, which seal conventional downhole seal cylinders. When the downhole seal cylinder has coating peeling off, or the seal cylinder surface is damaged due to well fluid erosion, tool scratches, etc., the traditional sealing module can no longer meet the sealing requirements, and an expansion insert seal needs to be inserted for operation.

[0003] However, there is no mature and effective way to confirm the damage degree of the underground sealing tube. If the expansion insert seal fails to achieve effective sealing due to the failure to find the correct position of the sealing tube or the sealing tube is seriously damaged, the well can only be overhauled, which affects the normal oil production operation. Summary of the invention

[0004] The present invention aims to solve the deficiencies of the prior art and provides a sealing inspection device and a sealing inspection method for installation of an expansion type insert seal.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A seal inspection device for expansion type insert seal installation comprises a seal inspection device body, the seal inspection device body comprises a ball seat outer sleeve, a ball seat nut is installed at the bottom of the ball seat outer sleeve, a center tube is plugged and installed at the top of the ball seat outer sleeve, a ball seat is installed in the ball seat outer sleeve below the center tube, the lower end of the ball seat side wall is installed on the ball seat outer sleeve through shear nails, a flow hole is provided on the side wall of the ball seat outer sleeve corresponding to the side wall of the ball seat, the flow hole is located above the shear nail, and an upper compression piston, a first sealing rubber cylinder, a seal inspection sleeve, a second sealing rubber cylinder are installed on the outer wall of the center tube in sequence from top to bottom. A sealing rubber cylinder and a lower compression piston, the top of the sealing inspection sleeve is provided with an inner sleeve inserted between the inner wall of the first sealing rubber cylinder and the outer wall of the center tube, the outside of the center tube is provided with a first return compression spring between the top of the inner sleeve and the upper compression piston, the outside of the center tube is provided with a second return compression spring between the bottom of the inner sleeve and the lower compression piston, a cavity is provided between the sealing inspection sleeve and the center tube for the top of the lower compression piston to penetrate, the sealing inspection sleeve and the center tube are provided with corresponding through holes at the cavity, the part of the lower compression piston that penetrates the cavity is provided with a sealing inspection hole, and the center tube is provided with pressure transmission holes corresponding to the upper compression piston and the lower compression piston.

[0007] It also includes a sealing ball that is put into the ball seat during sealing inspection.

[0008] A connecting thread for connecting with the oil pipe is arranged at the top of the center pipe.

[0009] The ball seat is provided with an inner hole for the sealing ball to be put into, the upper end of the inner hole is a constant diameter structure and the lower end is a non-constant diameter structure which is wide at the top and narrow at the bottom.

[0010] The outer sleeve of the ball seat is provided with a mounting hole for installing the shear nail, and the side wall of the ball seat is provided with a shear nail insertion hole matched with the mounting hole, and the shear nail is arranged in the mounting hole and the shear nail insertion hole.

[0011] The flow holes are a plurality of holes circumferentially arranged on the outer sleeve of the ball seat.

[0012] The seal verification method of the above-mentioned expansion type insert seal installation seal verification device comprises the following specific steps:

[0013] S1. Install the sealing inspection device body at the bottom of the oil pipe, lower the sealing inspection device body to below the lowest sealing cylinder in the casing through the oil pipe, reverse the oil pipe, and lift the sealing inspection device body to the position of the lowest sealing cylinder;

[0014] S2, throw the sealing ball by hand to complete the sealing of the central tube, start to increase the pressure in the central tube to the predetermined sealing pressure, push the upper compression piston and the lower compression piston through the internal pressure transmission hole to squeeze the first sealing rubber cylinder and the second sealing rubber cylinder to expand, and complete the sealing of the sealing cylinder;

[0015] S3, determine the pressure change condition. When the wellhead has a pressure drop, it is determined that the first sealing rubber tube and the second sealing rubber tube have not entered the sealing tube or the damage degree of the sealing tube has exceeded the limit expansion amount of the first sealing rubber tube and the second sealing rubber tube; when the damage degree of the sealing tube is less than the limit expansion amount of the first sealing rubber tube and the second sealing rubber tube, the first sealing rubber tube and the second sealing rubber tube have not reached the limit expansion amount, that is, the sealing of the sealing tube has been completed, the through hole and the sealing hole are not connected, the pressure in the central tube cannot be transmitted, and a stable pressure state is formed without a pressure drop phenomenon. At this time, it can be proved that the sealing of the sealing tube is qualified and the sealing tube meets the use requirements;

[0016] S4. If the wellhead experiences a pressure drop, the pressure in the central tube is released to allow the first and second sealing rubber tubes to rebound. According to the normal well seal inspection and seal tube search operation procedures, the lowering depth of the seal inspection device body is adjusted and the seal inspection is performed again.

[0017] S5. Repeat the above operation until the sealing of each layer of sealing tube is completed. After the downhole sealing device is sealed, if it is necessary to connect the inside and outside, the shear nails can be cut off by pressurization to make the ball seat fall off and expose the flow hole to complete the internal and external connection operation, and then the downhole sealing device body is taken out;

[0018] S6. After the sealing is completed, if effective sealing cannot be achieved after following the well sealing operation procedures, it can be determined that the degree of damage to the sealing tube exceeds the limit expansion of the first sealing rubber tube and the second sealing rubber tube, and a major repair operation is required to replace the sealing tube; if the sealing is qualified, the supporting expansion insert seal is lowered according to the well operation procedures to complete the tubing operation.

[0019] The beneficial effect of the present invention is that the present invention can verify the damage of the underground sealing tube itself to ensure that the expanded insert seal can effectively achieve sealing and avoid unnecessary overhaul operations. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a structural schematic diagram of the sealing inspection device body;

[0021] Figure 2 This is a schematic diagram of the sealing inspection device during sealing inspection operation;

[0022] Figure 3 This is a schematic diagram of the structure after the expansion insert seal is installed;

[0023] In the figure: 1-ball seat outer sleeve; 2-ball seat nut; 3-center tube; 4-ball seat; 5-shear nail; 6-flow hole; 7-upper compression piston; 8-first sealing rubber cylinder; 9-sealing sleeve; 10-second sealing rubber cylinder; 11-lower compression piston; 12-inner sleeve; 13-first return spring; 14-second return spring; 15-through hole; 16-sealing hole; 17-pressure transmission hole; 18-sealing ball; 19-connecting thread; 20-oil pipe; 21-sealing device body; 22-casing; 23-sealing cylinder; 24-expansion insert seal;

[0024] The following is a detailed description of the embodiments of the present invention with reference to the accompanying drawings. DETAILED DESCRIPTION

[0025] The present invention will be further described below in conjunction with the accompanying drawings and embodiments:

[0026] like Figures 1 to 3As shown, a seal inspection device for expansion type insertion seal installation includes a seal inspection device body 21, the seal inspection device body 21 includes a ball seat outer sleeve 1, a ball seat nut 2 is installed at the bottom of the ball seat outer sleeve 1, a center tube 3 is plugged and installed at the top of the ball seat outer sleeve 1, a ball seat 4 is installed in the ball seat outer sleeve 1 below the center tube 3, the lower end of the side wall of the ball seat 4 is installed on the ball seat outer sleeve 1 through a shear nail 5, and a flow hole 6 is provided on the side wall of the ball seat outer sleeve 1 corresponding to the side wall of the ball seat 4, and the flow hole 6 is located above the shear nail 5, and an upper compression piston 7, a first sealing rubber cylinder 8, a seal inspection sleeve 9, a second sealing rubber cylinder 10 and The lower compression piston 11, the top of the sealing sleeve 9 is provided with an inner sleeve 12 inserted between the inner wall of the first sealing rubber tube 8 and the outer wall of the center tube 3, the outside of the center tube 3 is provided with a first return compression spring 13 between the top of the inner sleeve 12 and the upper compression piston 7, the outside of the center tube 3 is provided with a second return compression spring 14 between the bottom of the inner sleeve 12 and the lower compression piston 11, a cavity is provided between the sealing sleeve 9 and the center tube 3 for the top of the lower compression piston 11 to penetrate, the sealing sleeve 9 and the center tube 3 are correspondingly provided with through holes 15 at the cavity, the part of the lower compression piston 11 penetrating the cavity is provided with a sealing hole 16, and the center tube 3 is provided with pressure transmission holes 17 corresponding to the upper compression piston 7 and the lower compression piston 11.

[0027] It also includes a sealing ball 18 that is put into the ball seat 4 during seal inspection.

[0028] A connecting thread 19 for connecting with the oil pipe 20 is provided at the top of the center pipe 3 .

[0029] The ball seat 4 is provided with an inner hole for the sealing ball 18 to be placed in, the upper end of the inner hole is a constant diameter structure and the lower end is a non-constant diameter structure which is wide at the top and narrow at the bottom.

[0030] The outer sleeve 1 of the ball seat is provided with a mounting hole for installing the shear nail 5, and the side wall of the ball seat 4 is provided with a shear nail insertion hole that matches the mounting hole, and the shear nail 5 is arranged in the mounting hole and the shear nail insertion hole.

[0031] The flow holes 6 are a plurality of holes 6 which are circumferentially arranged on the outer sleeve 1 of the ball seat.

[0032] The seal verification method of the above-mentioned expansion type insert seal installation seal verification device comprises the following specific steps:

[0033] S1, install the sealing inspection device body 21 at the bottom of the oil pipe 20, lower the sealing inspection device body 21 through the oil pipe 20 to below the bottom sealing cylinder 23 in the casing 22, reversely lift the oil pipe 20, and lift the sealing inspection device body 21 to the position of the bottom sealing cylinder 23;

[0034] S2, hand throw the sealing ball 18 to complete the sealing of the central tube 3, start to increase the pressure in the central tube 3 to the predetermined sealing pressure, push the upper compression piston 7 and the lower compression piston 11 through the internal pressure transmission hole 17 to squeeze the first sealing rubber cylinder 8 and the second sealing rubber cylinder 10 to expand, and complete the sealing of the sealing cylinder 23;

[0035] S3, determine the pressure change condition. When the wellhead has a pressure drop, it is determined that the first sealing rubber tube 8 and the second sealing rubber tube 10 have not entered the sealing tube 23 or the damage degree of the sealing tube 23 has exceeded the limit expansion amount of the first sealing rubber tube 8 and the second sealing rubber tube 10; when the damage degree of the sealing tube 23 is less than the limit expansion amount of the first sealing rubber tube 8 and the second sealing rubber tube 10, the first sealing rubber tube 8 and the second sealing rubber tube 10 have not reached the limit expansion amount, that is, the sealing of the sealing tube 23 has been completed, the through hole 15 and the sealing hole 16 are not connected, the pressure in the central tube 3 cannot be transmitted, and a stable pressure state is formed without a pressure drop phenomenon. At this time, it can be proved that the sealing of the sealing tube 23 is qualified and the sealing tube 23 meets the use requirements;

[0036] S4. If the pressure drops at the wellhead, the pressure in the central tube 3 is released to make the first sealing rubber tube 8 and the second sealing rubber tube 10 rebound. According to the normal well seal inspection and operation procedures for finding the sealing tube 23, the lowering depth of the seal inspection device body 21 is adjusted and the seal inspection is performed again.

[0037] S5, repeat the above operation until the sealing of each layer of sealing cylinder 23 is completed. After the downhole sealing device body 21 is sealed, when it is necessary to connect the inside and outside, the shear nail 5 can be cut off by pressurization to make the ball seat 4 fall off, exposing the flow hole 6, so as to complete the inside and outside connection operation, and then remove the downhole sealing device body 21;

[0038] S6. After the sealing is completed, if effective sealing cannot be achieved after following the well sealing operation procedures, it can be determined that the degree of damage to the sealing tube 23 exceeds the limit expansion of the first sealing rubber tube 8 and the second sealing rubber tube 10, and a major repair operation is required to replace the sealing tube 23; if the sealing is qualified, the supporting expansion insert seal 24 is lowered according to the well operation procedures to complete the pipe string operation.

[0039] The present invention can verify the damage of the underground sealing cylinder itself, so as to ensure that the expanded insert seal can effectively achieve sealing and avoid unnecessary overhaul operations.

[0040] The present invention is described above by way of example in conjunction with the accompanying drawings. It is obvious that the specific implementation of the present invention is not limited to the above-mentioned method. As long as various improvements are made using the method concept and technical solution of the present invention, or are directly applied to other occasions without improvement, they are all within the protection scope of the present invention.

Claims

1. A method for verifying the seal of an expansion type insert seal installation device, characterized in that: The seal inspection device for expansion type insert seal installation comprises a seal inspection device body (21), the seal inspection device body (21) comprises a ball seat outer sleeve (1), a ball seat nut (2) is installed at the bottom of the ball seat outer sleeve (1), a center tube (3) is plugged and installed at the top of the ball seat outer sleeve (1), a ball seat (4) is installed inside the ball seat outer sleeve (1) below the center tube (3), the lower end of the side wall of the ball seat (4) is installed on the ball seat outer sleeve (1) through a shear nail (5), a flow hole (6) is provided on the side wall of the ball seat outer sleeve (1) corresponding to the side wall of the ball seat (4), and the flow hole (6) is located above the shear nail (5), an upper compression piston (7), a first sealing rubber tube (8), a seal inspection sleeve (9), a second sealing rubber tube (10) and a lower compression piston (11) are installed on the outer wall of the center tube (3) in sequence from top to bottom, and the top of the seal inspection sleeve (9) is provided with a plug inserted into the first sealing rubber tube (8) An inner sleeve (12) is provided between the inner sleeve (12) and the outer wall of the center tube (3); a first return compression spring (13) is provided outside the center tube (3) between the top of the inner sleeve (12) and the upper compression piston (7); a second return compression spring (14) is provided outside the center tube (3) between the bottom of the inner sleeve (12) and the lower compression piston (11); a cavity is provided between the sealing inspection sleeve (9) and the center tube (3) for the top of the lower compression piston (11) to penetrate; through holes (15) are provided on the sealing inspection sleeve (9) and the center tube (3) at the cavity; a sealing inspection hole (16) is provided at the portion where the lower compression piston (11) penetrates the cavity; and pressure transmission holes (17) are provided on the center tube (3) corresponding to the upper compression piston (7) and the lower compression piston (11); and the center tube (3) also includes a sealing ball (18) which is put into the ball seat (4) during sealing inspection; and a connecting thread (19) is provided at the top of the center tube (3) for connecting with the oil pipe (20); The specific steps are: S1, installing the sealing inspection device body (21) at the bottom of the oil pipe (20), lowering the sealing inspection device body (21) through the oil pipe (20) to below the bottommost sealing cylinder (23) in the casing (22), lifting the oil pipe (20) in reverse, and lifting the sealing inspection device body (21) to the position of the bottommost sealing cylinder (23); S2, manually throwing the sealing ball (18) to complete the sealing of the central tube (3), starting to increase the pressure inside the central tube (3) to a predetermined sealing pressure, pushing the upper compression piston (7) and the lower compression piston (11) through the internal pressure transmission hole (17) to squeeze the first sealing rubber cylinder (8) and the second sealing rubber cylinder (10) to expand, and completing the sealing of the sealing cylinder (23); S3, determining the pressure change condition. When the wellhead has a pressure drop, it is determined that the first sealing rubber tube (8) and the second sealing rubber tube (10) have not entered the sealing tube (23) or the damage degree of the sealing tube (23) has exceeded the limit expansion amount of the first sealing rubber tube (8) and the second sealing rubber tube (10); when the damage degree of the sealing tube (23) is less than the limit expansion amount of the first sealing rubber tube (8) and the second sealing rubber tube (10), the first sealing rubber tube (8) and the second sealing rubber tube (10) have not reached the limit expansion amount, that is, the sealing of the sealing tube (23) has been completed, the through hole (15) and the sealing hole (16) are not connected, the pressure in the central tube (3) cannot be transmitted, and a stable pressure state is formed without a pressure drop phenomenon. At this time, it can be proved that the sealing of the sealing tube (23) is qualified and the sealing tube (23) meets the use requirements; S4. If the wellhead experiences a pressure drop, the pressure in the central tube (3) is released to allow the first sealing rubber tube (8) and the second sealing rubber tube (10) to rebound. According to the normal well seal inspection and operation procedures for finding the sealing tube (23), the lowering depth of the sealing inspection device body (21) is adjusted and the seal inspection is performed again. S5, repeat the above operation until the sealing of each layer of sealing cylinder (23) is completed. After the downhole sealing device body (21) is sealed, when it is necessary to connect the inside and outside, the shear nail (5) can be cut off by pressurization to make the ball seat (4) fall off, exposing the flow hole (6), so as to complete the inside and outside connection operation, and then remove the downhole sealing device body (21); S6. After the sealing is completed, if effective sealing cannot be achieved after following the wellbore sealing operation procedures, it can be determined that the degree of damage to the sealing tube (23) exceeds the limit expansion amount of the first sealing rubber tube (8) and the second sealing rubber tube (10), and a major repair operation is required to replace the sealing tube (23); if the sealing is qualified, the supporting expansion insert seal (24) is lowered according to the wellbore operation procedures to complete the pipe string operation.

2. A sealing inspection method for a sealing inspection device for installation of an expansion type insert seal according to claim 1, characterized in that: The ball seat (4) is provided with an inner hole for inserting a sealing ball (18), the upper end of the inner hole is a constant diameter structure and the lower end is a non-constant diameter structure which is wide at the top and narrow at the bottom.

3. A sealing inspection method for a sealing inspection device for installation of an expansion type insert seal according to claim 2, characterized in that: The outer sleeve (1) of the ball seat is provided with a mounting hole for mounting a shear nail (5), and the side wall of the ball seat (4) is provided with a shear nail insertion hole matching the mounting hole. The shear nail (5) is arranged in the mounting hole and the shear nail insertion hole.

4. A sealing inspection method for a sealing inspection device for installation of an expansion type insert seal according to claim 3, characterized in that: The flow holes (6) are a plurality of holes circumferentially arranged on the outer sleeve (1) of the ball seat.

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