Valveless hydraulic setting tool for bridge plug

Abstract

The invention provides a valveless hydraulic setting tool for a bridge plug. The valveless hydraulic setting tool comprises a positive and negative rotation motor, an upper connector, a sleeve, a two-way hydraulic pump, a soft oil pipe, an oil storage tank, a push rod piston and a check ring. A sleeve in the upper connector is connected with a forward and reverse rotation motor and a shaft of a two-way hydraulic pump, a soft oil pipe is connected with the two-way hydraulic pump and the upper end of a push rod piston, the push rod piston and the inner wall of a cylinder barrel form a first sealing cavity and a second sealing cavity, and a first hollow oil way and a second hollow oil way are arranged in the push rod piston. The first hollow oil way is communicated with the soft oil pipe and the first sealing cavity, the second hollow oil way is communicated with the oil storage tank and the second sealing cavity, and the lower end of the push rod piston is connected with the bridge plug through the bridge plug upper connector. Setting action and reset recovery action are achieved through forward rotation and reverse rotation of the forward and reverse rotation motor, and the packer is reasonable in structure, easy to operate, high in efficiency, shorter in length, convenient to transport and capable of being repeatedly used.

Description

[0001] This application is a divisional application based on a patent application with an application date of September 14, 2020, application number 2020109596970, and invention name “A valveless hydraulic sealing tool for a bridge plug”. Technical Field

[0002] The invention belongs to the technical field of oilfield development and production, and in particular relates to a bridge plug valveless hydraulic setting tool. Background Art

[0003] In oil exploration and development, the application of fracturing reservoir transformation technology is becoming more and more widespread, and bridge plug staged fracturing operations have become a common fracturing method in the industry. At present, the way to set a bridge plug is to use a bridge plug setting tool, and cable bridge plug setting tools and hydraulic bridge plug setting tools are the most commonly used. The cable bridge plug setting tool uses gunpowder combustion to generate high-pressure gas to provide the setting force, but the use of this tool has safety hazards and high costs; the hydraulic bridge plug setting tool is equipped with a one-way valve and is long, which has problems such as non-reusability, complex operation, difficulty in transportation, and low efficiency. Summary of the invention

[0004] The object of the present invention is to provide a bridge plug valveless hydraulic setting tool, which is used to solve the problems of non-reusability, complex operation, long length and low efficiency.

[0005] The technical solution of the present invention:

[0006] To achieve the above-mentioned and other purposes, the present invention provides a bridge plug valveless hydraulic sealing tool, comprising: a forward and reverse motor, an upper joint, a sleeve and a cylinder, wherein a two-way hydraulic pump, a soft oil pipe, an oil storage tank, a push rod piston and a stop ring for stopping the downward movement of the push rod piston are arranged inside the cylinder, the forward and reverse motor is fixed to the upper joint by bolts, the sleeve is arranged inside the upper joint, the upper end of the two-way hydraulic pump is fixed to an end of the upper joint away from the forward and reverse motor by bolts, the lower end oil port of the two-way hydraulic pump is connected to the upper end of the soft oil pipe, the lower end inner ring of the soft oil pipe is connected to the upper end hole of the push rod piston, the push rod piston is provided with a first hollow oil path and a second hollow oil path, and the lower end of the push rod piston is connected to the bridge plug;

[0007] Wherein, the space between the outer wall of the two-way hydraulic pump, the outer wall of the soft oil pipe and the inner wall of the cylinder is an oil storage tank, an oil port connected to the oil storage tank is opened on the side wall of the two-way hydraulic pump, the push rod piston has three piston heads, and the three piston heads are all sealed and connected to the cylinder wall of the cylinder, and three groups of sealed cavities corresponding to the three piston heads are formed between the push rod piston and the inner wall of the cylinder, each group of sealed cavities includes a first sealed cavity and a second sealed cavity, the first hollow oil path is respectively connected to the soft oil pipe and the three first sealed cavities, the second hollow oil path is respectively connected to the oil storage tank and two second sealed cavities close to the oil storage tank, and the gear ring includes at least one, which is arranged in the first sealed cavity;

[0008] Furthermore, the sleeve is connected to the shafts of the forward and reverse motor and the bidirectional hydraulic pump respectively through keys.

[0009] Furthermore, the volume of the oil storage tank is approximately 10 times the volume occupied by the soft oil pipe to ensure that there is enough oil available in the oil storage tank.

[0010] Furthermore, the diameter of the push rod portion of the push rod piston is the same as the outer diameter of the soft oil pipe, so that the flow rates of oil inlet and oil outlet are consistent, the piston movement speed is stable, and a sufficiently large sealing force is continuously output.

[0011] Furthermore, the three piston heads of the push rod piston are respectively sealed and connected to the cylinder wall via sealing rings.

[0012] Furthermore, pressure sensors are provided at the stop ring and the bottom end of the push rod piston. The pressure sensor at the stop ring is used to determine when the push rod piston reaches the stop ring by detecting pulses, that is, the reset is completed; the pressure sensor at the bottom end of the push rod piston is used to determine when the bridge plug is set and the oil pump is stopped by detecting pulses, and the bridge plug valveless hydraulic setting tool is lifted and recovered.

[0013] Furthermore, the forward and reverse motor is a forward and reverse frequent starting motor. The forward and reverse rotation of the motor drives the forward and reverse rotation of the bidirectional hydraulic pump to complete the oil inlet and oil return, thereby realizing the bridge plug setting and push rod piston reset functions.

[0014] Furthermore, the three first sealed cavities have the same shape and volume, and the two second sealed cavities have the same shape and volume.

[0015] Compared with the prior art, the present invention provides a bridge plug valveless hydraulic setting tool, which has a reasonable structure, simple operation and high efficiency. The bridge plug valveless hydraulic setting tool is shorter than the existing hydraulic setting tool, reduces labor costs and is easy to transport. The bridge plug valveless hydraulic setting tool is reusable and can be automatically switched between setting and resetting by simply rotating the bidirectional hydraulic pump forward and backward. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 Schematic diagram of the structure of the bridge plug valveless hydraulic setting tool of the present invention, wherein (a) is the upper half structure of the bridge plug valveless hydraulic setting tool, and (b) is the lower half structure of the bridge plug valveless hydraulic setting tool;

[0017] Figure 2 For attachment Figure 1 A schematic diagram of the enlarged structure at A in the middle;

[0018] Figure 3 This is a working state diagram of the valveless hydraulic setting tool for the bridge plug of the present invention;

[0019] Figure numerals: 1. forward and reverse motor; 2. upper joint; 3. sleeve; 4. bidirectional hydraulic pump; 4a. oil port; 5. soft oil pipe; 6. oil storage tank; 7. push rod piston; 7a. first hollow oil path; 7b. second hollow oil path; 8a. first sealing chamber; 8b. second sealing chamber; 9. sealing ring; 10. shift ring; 11. upper joint of bridge plug; 12. drillable slip; 13. shear pin; 14. release pin; 15. hollow pin; 16. cylinder barrel. DETAILED DESCRIPTION

[0020] In order to further understand the present invention, preferred embodiments of the present invention are described below in conjunction with examples, but it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, rather than limiting the claims of the present invention.

[0021] like Figure 1 (a) Figure 1 (b) Figure 2 and Figure 3 As shown, the present invention provides a bridge plug valveless hydraulic setting tool, comprising: a forward and reverse motor 1, an upper joint 2, a sleeve 3 and a cylinder 16, wherein a bidirectional hydraulic pump 4, a soft oil pipe 5, an oil storage tank 6, a push rod piston 7 and a stop ring 10 for stopping the downward movement of the push rod piston 7 are arranged inside the cylinder 16, the forward and reverse motor 1 is fixed with the upper joint 2 by bolts, the sleeve 3 is arranged inside the upper joint 2, and is connected with the shafts of the forward and reverse motor 1 and the bidirectional hydraulic pump 4 respectively by keys. The upper end of the bidirectional hydraulic pump 4 is fixed with the end of the upper joint 2 away from the forward and reverse motor 1 by bolts, the lower end oil port of the bidirectional hydraulic pump 4 is connected with the upper end of the soft oil pipe 5, the lower end inner ring of the soft oil pipe 5 is connected with the upper end hole of the push rod piston 7, the push rod piston 7 is provided with a first hollow oil path 7a and a second hollow oil path 7b, and the lower end of the push rod piston 7 is connected with the bridge plug; the bridge plug comprises: a bridge plug upper joint 11, a drillable slip 12, a shear pin 13, a release pin 14 and a hollow pin 15. In the present invention, the forward and reverse motor 1 is preferably a forward and reverse frequent starting motor.

[0022] Among them, the space between the outer wall of the two-way hydraulic pump 4, the outer wall of the soft oil pipe 5 and the inner wall of the cylinder 16 is an oil storage tank 6, and an oil port 4a connected to the oil storage tank 6 is opened on the side wall of the two-way hydraulic pump 4. The push rod piston 7 has three piston heads, and the three piston heads are sealed and connected to the inner wall of the cylinder 16 through a sealing ring 9. Three groups of sealed cavities corresponding to the three piston heads are formed between the push rod piston 7 and the inner wall of the cylinder 16, and each group of sealed cavities includes a first sealed cavity 8a and a second sealed cavity 8b. The first hollow oil passage 7a is respectively connected to the soft oil pipe 5 and the three first sealed cavities 8a, and the second hollow oil passage 7b is respectively connected to the oil storage tank 6 and the two second sealed cavities 8b near the upper end. The gear ring 10 includes at least one, which is arranged in the first sealed cavity 8a. Preferably, only one gear ring 10 can be arranged, corresponding to the position of the piston head located in the middle position, and arranged in the first sealed cavity 8a located in the middle position. The three first sealed cavities 8a have the same shape and volume, and the two second sealed cavities 8b have the same shape and volume.

[0023] In a preferred embodiment of the present invention, the volume of the oil storage tank 6 is approximately 10 times the volume occupied by the soft oil pipe 5 to ensure that there is enough oil available in the oil storage tank.

[0024] In a preferred embodiment of the present invention, the diameter of the push rod portion of the push rod piston 7 is the same as the outer diameter of the soft oil pipe 5, so that the flow rates of the oil inlet and the oil outlet are consistent, the piston movement speed is stable, and a sufficiently large sealing force is continuously output.

[0025] In a preferred embodiment of the present invention, pressure sensors are provided at the stop ring 10 and at the bottom of the push rod piston 7. The pressure sensor at the stop ring 10 is used to determine when the push rod piston reaches the stop ring 10 by detecting pulses, that is, the reset is completed; the pressure sensor at the bottom of the push rod piston 7 is used to determine when the bridge plug is set and the oil pump is stopped by detecting pulses, and the bridge plug valveless hydraulic setting tool is lifted and recovered.

[0026] In the present invention, the bridge plug valveless hydraulic setting tool is connected to the bridge plug upper joint 11 through the cylinder 16 and the bottom joint of the push rod piston 7. The bridge plug valveless hydraulic setting tool detects pulses through a pressure sensor to determine when the bridge plug is completed and the oil pump is stopped, and the bridge plug valveless hydraulic setting tool is lifted up and recovered. The forward and reverse motor of the bridge plug valveless hydraulic setting tool drives the forward and reverse rotation of the bidirectional hydraulic pump to complete the oil inlet and oil return, thereby realizing the bridge plug setting and push rod piston reset functions.

[0027] When the forward and reverse motor 1 drives the bidirectional hydraulic pump 4 to rotate forward through the sleeve 3, the bidirectional hydraulic pump 4 draws oil from the oil storage tank 6, and the oil flows to the first hollow oil path 7a through the soft oil pipe 5 and enters the three first sealed chambers 8a. The volume of the three first sealed chambers 8a increases, thereby pushing the push rod piston 7 to move upward, and the volume of the two second sealed chambers 8b decreases, and the soft oil pipe 5 bends accordingly. When the pressure sensor located at the bottom end of the push rod piston 7 is used to detect that the bridge plug has been set by detecting pulses, the forward and reverse motor 1 drives the bidirectional hydraulic pump 4 to reverse, and the oil is drawn from the first sealed chamber 8a and flows back to the bidirectional hydraulic pump 4 through the soft oil pipe 5. The oil then returns to the oil storage tank 6 from the oil port 4a of the bidirectional hydraulic pump 4, and then enters the two second sealed chambers 8b connected thereto through the second hollow oil path 7b, thereby pushing the push rod piston 7 to move downward, and the first sealed chamber 8a decreases, and the soft oil pipe 5 extends accordingly, until the pressure sensor located at the gear ring 10 detects that any piston head of the push rod piston 7 reaches the gear ring 10, stops moving, and returns to its original position.

[0028] When using the present invention, the motor is connected to the upper joint 2 of the bridge plug valveless hydraulic setting tool, and then the cylinder 16 of the bridge plug valveless hydraulic setting tool and the bottom joint of the push rod piston 7 are connected to the bridge plug through the bridge plug upper joint 11. The connected bridge plug valveless hydraulic setting tool is connected to the end of the pipe string. When the pipe string is lowered to the predetermined position, the forward and reverse motor 1 is started and rotated forward, and then the bidirectional hydraulic pump 4 is controlled to rotate forward, and the oil enters the three first sealing chambers 8a, generating a driving force, and the push rod piston 7 moves upward to start the bridge plug setting process. During the movement of the push rod piston 7, the push rod piston rod 7 gradually increases the pressure of the cylinder to the bridge plug, and then the shear pin 13, the hollow pin 15 and the release pin 14 of the bridge plug are cut off in sequence, and at the same time, the pressure of the first sealing chamber 8a drops three times. When the pressure sensor detects that the pulse drops for the third time, it means that the pressure of the cylinder 16 on the bridge plug reaches the maximum, that is, the driving force of the bridge plug reaches the maximum. When it exceeds the maximum value that the bridge plug can withstand when it is released, it is released and the motor is powered off. To facilitate the next use, the bridge plug valveless hydraulic setting tool is recovered along with the pipe string, the forward and reverse motor 1 is started to reverse, and then the bidirectional hydraulic pump 4 is controlled to reverse, and the oil enters the two second sealing chambers 8b, generating a driving force, and the push rod piston 7 moves downward to achieve the reset function. When the pressure sensor detects that the pulse at the gear ring increases, it means that the reset is completed, the forward and reverse motor 1 is turned off, and the bridge plug valveless hydraulic setting tool is lifted out of the wellhead along with the pipe string.

[0029] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the attached claims rather than the above description, and it is intended to include all changes within the meaning and scope of the equivalent elements of the claims. Although the embodiments of the present invention have been shown and described, it is understood by those of ordinary skill in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the attached claims and their equivalents.

Claims

1. A bridge plug valveless hydraulic setting tool, characterized in that: include: A forward and reverse motor (1), an upper joint (2), a sleeve (3) and a cylinder (16); a bidirectional hydraulic pump (4), a soft oil pipe (5), an oil storage tank (6), a push rod piston (7) and a stop ring (10) for stopping the downward movement of the push rod piston (7) are arranged inside the cylinder (16); the forward and reverse motor (1) and the upper joint (2) are fixed by bolt connection; the sleeve (3) is arranged inside the upper joint (2); the upper end of the bidirectional hydraulic pump (4) and an end of the upper joint (2) away from the forward and reverse motor (1) are fixed by bolt connection; the lower end oil port of the bidirectional hydraulic pump (4) is connected to the upper end of the soft oil pipe (5); the lower end inner ring of the soft oil pipe (5) is connected to the upper end hole of the push rod piston (7); a first hollow oil path (7a) and a second hollow oil path (7b) are arranged inside the push rod piston (7); the lower end of the push rod piston (7) is connected to a bridge plug; The space between the outer wall of the bidirectional hydraulic pump (4), the outer wall of the soft oil pipe (5) and the inner wall of the cylinder (16) is an oil storage tank (6); an oil port (4a) connected to the oil storage tank (6) is provided on the side wall of the bidirectional hydraulic pump (4); the push rod piston (7) has three piston heads, and the three piston heads are sealed to the inner wall of the cylinder (16); three groups of sealed cavities corresponding to the piston heads are formed between the push rod piston (7) and the inner wall of the cylinder (16); each group of sealed cavities includes a first sealed cavity (8a) and a second sealed cavity (8b); the first hollow oil path (7a) is respectively connected to the soft oil pipe (5) and the three first sealed cavities (8a); the second hollow oil path (7b) is respectively connected to the oil storage tank (6) and two second sealed cavities (8b) close to the oil storage tank (6); and at least one gear ring (10) is arranged in the first sealed cavity (8a); During the movement of the push rod piston (7), the push rod piston (7) causes the pressure of the cylinder barrel to gradually increase. Subsequently, the shear pin (13), the hollow pin (15) and the release pin (14) of the bridge plug are sheared off in sequence. At the same time, the pressure of the first sealing chamber (8a) drops three times. When the pressure sensor detects the third sudden drop of the pulse, the pressure of the cylinder barrel (16) on the bridge plug reaches the maximum. When it exceeds the maximum value that the bridge plug can withstand when released, it is released and the forward and reverse motors are powered off.

2. The bridge plug valveless hydraulic setting tool according to claim 1, characterized in that: The sleeve (3) is connected to the shafts of the forward and reverse motor (1) and the bidirectional hydraulic pump (4) respectively through keys.

3. The bridge plug valveless hydraulic setting tool according to claim 1, characterized in that: The volume of the oil storage tank (6) is approximately 10 times the volume occupied by the soft oil pipe (5).

4. The bridge plug valveless hydraulic setting tool according to claim 1, characterized in that: The diameter of the push rod portion of the push rod piston (7) is the same as the outer diameter of the soft oil pipe (5).

5. The bridge plug valveless hydraulic setting tool according to claim 1, characterized in that: The three piston heads of the push rod piston (7) are respectively sealedly connected to the inner wall of the cylinder barrel (16) via sealing rings (9).

6. The bridge plug valveless hydraulic setting tool according to claim 1, characterized in that: Pressure sensors are provided at the stop ring (10) and the bottom end of the push rod piston (7).

7. The bridge plug valveless hydraulic setting tool according to claim 1, characterized in that: The forward and reverse motor (1) is a forward and reverse frequent starting motor.

8. The bridge plug valveless hydraulic setting tool according to claim 1, characterized in that: The first sealed cavities (8a) have the same shape and volume, and the second sealed cavities (8b) have the same shape and volume.

9. The bridge plug valveless hydraulic setting tool according to claim 1, characterized in that: When in use, the forward and reverse motor (1) is connected to the upper joint (2) of the bridge plug valveless hydraulic sealing tool, and then the cylinder barrel (16) and the bottom joint of the push rod piston (7) of the bridge plug valveless hydraulic sealing tool are connected to the bridge plug through the bridge plug upper joint (2); Connect the connected bridge plug valveless hydraulic setting tool to the end of the pipe string; When the pipe string is lowered to a predetermined position, the forward and reverse motor (1) is started and made to rotate forward, thereby controlling the bidirectional hydraulic pump (4) to rotate forward, and oil enters the three first sealing chambers (8a), generating a driving force, causing the push rod piston (7) to move upward, thereby starting the bridge plug setting process.

10. The bridge plug valveless hydraulic setting tool according to claim 1, characterized in that: When the forward and reverse motor (1) drives the bidirectional hydraulic pump (4) to rotate forward through the sleeve (3), the bidirectional hydraulic pump (4) draws oil from the oil storage tank (6), and the oil then flows to the first hollow oil path (7a) through the soft oil pipe (5) and enters the three first sealed chambers (8a). The volume of the three first sealed chambers (8a) increases, thereby pushing the push rod piston (7) to move upward, and the volume of the two second sealed chambers (8b) decreases. At the same time, the soft oil pipe (5) bends accordingly. When the pressure sensor located at the bottom end of the push rod piston (7) detects that the bridge plug has been sealed by detecting pulses, the forward and reverse motor (1) drives the bidirectional hydraulic pump (4) to rotate forward. The hydraulic pump (4) reverses, draws oil from the first sealed chamber (8a) and flows back to the bidirectional hydraulic pump (4) through the soft oil pipe (5), and the oil then returns to the oil storage tank (6) from the oil port (4a) of the bidirectional hydraulic pump (4), and then enters the two second sealed chambers (8b) connected thereto through the second hollow oil path (7b), thereby pushing the push rod piston (7) to move downward, the first sealed chamber (8a) shrinks, and the soft oil pipe (5) extends accordingly, until the pressure sensor located at the stop ring (10) detects that any piston head of the push rod piston (7) reaches the stop ring (10), stops moving, and returns to its original position.

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