A bridge plug valveless hydraulic setting tool

Abstract

The present invention provides a bridge plug valveless hydraulic sealing tool, comprising: a forward and reverse motor, an upper joint, a sleeve, a bidirectional hydraulic pump, a soft oil pipe, an oil storage tank, a push rod piston, and a shift ring. The sleeve inside the upper joint is connected to the shafts of the forward and reverse motor and the bidirectional hydraulic pump, the soft oil pipe is connected to the bidirectional hydraulic pump and the upper end of the push rod piston, the push rod piston forms a first sealing chamber and a second sealing chamber with the inner wall of the cylinder, and a first hollow oil passage and a second hollow oil passage are provided inside the push rod piston, the first hollow oil passage is connected to the soft oil pipe and the first sealing chamber, the second hollow oil passage is connected to the oil storage tank and the second sealing chamber, and the lower end of the push rod piston is connected to the bridge plug through the bridge plug upper joint. The present invention realizes the sealing action and the resetting and recovery action through the forward and reverse rotation of the forward and reverse motor, has a reasonable structure, is simple to operate, has high efficiency, is shorter in length, is easy to transport, and is reusable.

Description

[0001] This application is a divisional application based on the patent application with application date of September 14, 2020, application number 2020109596970, and invention name “A valveless hydraulic sealing tool for 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, fracturing reservoir stimulation technology is increasingly being used, and bridge plug staged fracturing has become a common fracturing method within the industry. Currently, bridge plug setting tools are used to set bridge plugs, with cable and hydraulic bridge plug setting tools being the most commonly used. Cable bridge plug setting tools utilize high-pressure gas generated by burning gunpowder to provide the setting force, but this approach carries safety risks and is costly. Hydraulic bridge plug setting tools, which are equipped with a check valve and are relatively long, present issues such as non-reusability, complex operation, difficulty in transportation, and low efficiency. Summary of the Invention

[0004] The purpose of the present invention is to provide a valveless hydraulic setting tool for a bridge plug, 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 and the upper joint are fixed by bolts, the sleeve is arranged inside the upper joint, the upper end of the two-way hydraulic pump and the end of the upper joint away from the forward and reverse motor are fixed 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 with 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 the sealed cavities includes a first sealed cavity and a second sealed cavity, the first hollow oil path is respectively connected with the soft oil pipe and the three first sealed cavities, the second hollow oil path is respectively connected with 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 of 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 setting force is continuously output.

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

[0012] Furthermore, pressure sensors are provided at the retaining ring and the bottom end of the push rod piston. The retaining ring pressure sensor detects pulses to determine when the push rod piston reaches the retaining ring, i.e., when reset is complete. The pressure sensor at the bottom end of the push rod piston detects pulses to determine when the bridge plug is set, the oil pump is stopped, 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 supply 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 to existing technologies, the present invention provides a valveless hydraulic setting tool for bridge plugs, featuring a rational structure, simple operation, and high efficiency. This valveless hydraulic setting tool is shorter than existing hydraulic setting tools, reducing labor costs and facilitating transportation. This valveless hydraulic setting tool is reusable and automatically switches between setting and resetting by simply rotating a bidirectional hydraulic pump in both forward and reverse directions. 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) shows the upper half of the bridge plug valveless hydraulic setting tool, and (b) shows the lower half of the bridge plug valveless hydraulic setting tool;

[0017] Figure 2 For attachment Figure 1 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 passage; 7b. Second hollow oil passage; 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. DETAILED DESCRIPTION

[0020] In order to further understand the present invention, preferred embodiments of the present invention are described below in conjunction with examples. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, rather than for 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 valveless hydraulic setting tool for a bridge plug, comprising: a forward / reversible motor 1, an upper joint 2, a sleeve 3, and a cylinder 16. Cylinder 16 is internally provided with a bidirectional hydraulic pump 4, a flexible oil pipe 5, an oil reservoir 6, a push rod piston 7, and a stop ring 10 for stopping the downward movement of the push rod piston 7. The forward / reversible motor 1 is fixed to the upper joint 2 via bolts. The sleeve 3 is disposed within the upper joint 2 and is connected to the shafts of the forward / reversible motor 1 and the bidirectional hydraulic pump 4, respectively, via keys. The upper end of the bidirectional hydraulic pump 4 is bolted to the end of the upper joint 2 away from the forward / reversible motor 1. The lower oil port of the bidirectional hydraulic pump 4 is connected to the upper end of the flexible oil pipe 5. The inner ring of the lower end of the flexible oil pipe 5 is connected to the upper end hole of the push rod piston 7. The push rod piston 7 is provided with a first hollow oil passage 7a and a second hollow oil passage 7b. The lower end of the push rod piston 7 is connected to the bridge plug. The bridge plug comprises: an 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] The space between the outer wall of the bidirectional hydraulic pump 4, the outer wall of the flexible oil pipe 5, and the inner wall of the cylinder 16 forms an oil reservoir 6. An oil port 4a is provided on the side wall of the bidirectional hydraulic pump 4, communicating with the oil reservoir 6. The push rod piston 7 has three piston heads, each of which is sealed to the inner wall of the cylinder 16 via a sealing ring 9. Three sealed chambers corresponding to the three piston heads are formed between the push rod piston 7 and the inner wall of the cylinder 16. Each sealed chamber includes a first sealed chamber 8a and a second sealed chamber 8b. The first hollow oil passage 7a communicates with the flexible oil pipe 5 and the three first sealed chambers 8a, respectively. The second hollow oil passage 7b communicates with the oil reservoir 6 and the two second sealed chambers 8b near the upper end, respectively. At least one shift ring 10 is provided, disposed in each of the first sealed chambers 8a. Preferably, only one shift ring 10 may be provided, corresponding to the position of the piston head in the middle position, and disposed in the middle first sealed chamber 8a. The three first sealed chambers 8a have the same shape and volume, and the two second sealed chambers 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 flexible 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 oil inlet and outlet are consistent, the piston movement speed is stable, and a sufficiently large setting force is continuously output.

[0025] In a preferred embodiment of the present invention, pressure sensors are installed at the shift ring 10 and at the bottom end of the push rod piston 7. The pressure sensor at the shift ring 10 detects pulses to determine when the push rod piston reaches the shift ring 10, indicating the end of reset. The pressure sensor at the bottom end of the push rod piston 7 detects pulses to determine when the bridge plug is set, stops the oil pump, and lifts the bridge plug valveless hydraulic setting tool for recovery.

[0026] In the present invention, the valveless hydraulic setting tool for the bridge plug is connected to the upper connector 11 of the bridge plug via a cylinder 16 and the bottom connector of the push rod piston 7. The tool detects pulses via a pressure sensor to determine when the bridge plug is set and to stop the oil pump. The tool is then lifted and recovered. The tool's forward and reverse motor drives the bidirectional hydraulic pump in forward and reverse rotation to supply and return oil, thereby setting the bridge plug and resetting the push rod piston.

[0027] When the forward / reverse motor 1 drives the bidirectional hydraulic pump 4 forward through the sleeve 3, the bidirectional hydraulic pump 4 draws oil from the oil reservoir 6. The oil then flows through the flexible oil pipe 5 to the first hollow oil passage 7a and into the three first sealed chambers 8a. The volume of the three first sealed chambers 8a increases, thereby pushing the push rod piston 7 upward. The volume of the two second sealed chambers 8b decreases, and the flexible oil pipe 5 bends accordingly. When the pressure sensor at the bottom end of the push rod piston 7 detects that the bridge plug has been set through the detection pulse, the forward / reverse motor 1 drives the bidirectional hydraulic pump 4 in reverse, drawing oil from the first sealed chamber 8a and flowing back to the bidirectional hydraulic pump 4 through the flexible oil pipe 5. The oil then returns to the oil reservoir 6 from the oil port 4a of the bidirectional hydraulic pump 4, and then enters the two connected second sealed chambers 8b through the second hollow oil passage 7b, thereby pushing the push rod piston 7 downward. The first sealed chamber 8a decreases, and the flexible oil pipe 5 extends accordingly. Until the pressure sensor at the shift ring 10 detects that either piston head of the push rod piston 7 has reached the shift ring 10, the piston stops moving, i.e., returns to its original position.

[0028] When using the present invention, the motor is connected to the upper connector 2 of the valveless hydraulic setting tool for the bridge plug. The cylinder 16 and the bottom connector of the push rod piston 7 are then connected to the bridge plug via the upper connector 11. The connected valveless hydraulic setting tool is then connected to the end of the tubing string. When the tubing string is lowered to the desired position, the forward and reverse motor 1 is activated and rotated forward, thereby controlling the forward rotation of the bidirectional hydraulic pump 4. Oil enters the three first sealing chambers 8a, generating a driving force that causes the push rod piston 7 to move upward, initiating the bridge plug setting process. During the movement of the push rod piston 7, the cylinder pressure applied to the bridge plug gradually increases. Subsequently, the shear pin 13, hollow pin 15, and release pin 14 of the bridge plug are sequentially sheared. Simultaneously, the pressure in the first sealing chamber 8a drops three times. When the pressure sensor detects the third sudden drop in pulses, it indicates that the pressure applied to the bridge plug by the cylinder 16 has reached its maximum, indicating that the driving force exerted on the bridge plug has reached its maximum. When the pressure exceeds the maximum value that the bridge plug can withstand during release, release is achieved and the motor is de-energized. To facilitate the next use, the valveless hydraulic setting tool is retrieved along with the tubing string. The forward and reverse motors 1 are activated, which in turn controls the reverse direction of the bidirectional hydraulic pump 4. Oil enters the two second sealing chambers 8b, generating a driving force that moves the push rod piston 7 downward, completing the reset function. When the pressure sensor detects an increase in pulses at the shift ring, the reset is complete. The forward and reverse motors 1 are turned off, and the valveless hydraulic setting tool is lifted out of the wellhead along with the tubing string.

[0029] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It is obvious to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and that 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 appended claims rather than the above description, and it is intended that all changes that fall within the meaning and scope of the equivalent elements of the claims are included in the present invention. Although embodiments of the present invention have been shown and described, it is understood by those skilled 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 appended claims and their equivalents.

Claims

1. A valveless hydraulic setting tool for a bridge plug, 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 the 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 provided 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 with 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 with the soft oil pipe (5) and the three first sealed cavities (8a); the second hollow oil path (7b) is respectively connected with the oil storage tank (6) and two second sealed cavities (8b) close to the oil storage tank (6); 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 the bridge plug to gradually increase, and then the shear pin (13), the hollow pin (15) and the release pin (14) of the bridge plug are sheared off in sequence, and 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) to 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 (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 shift 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 (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 motors (1) are started and rotated 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 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 at the bottom end of the push rod piston (7) is used to detect that the bridge plug has been sealed through the detection pulse, the forward and reverse motor (1) drives the bidirectional hydraulic pump (4) to rotate forward. The pressure 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 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.

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