Tool and method for determining form of leakage point

Abstract

The invention relates to the technical field of exploitation of unconventional oil and gas reservoirs such as petroleum and natural gas, in particular to a tool and method for determining the form of a leakage point. The problems that in the prior art, due to the fact that a construction pipe column is pulled out for one-by-one checking when casing pressure rises, the construction work amount is large, in the pipe column pulling process, the shapes of tools such as a packer on the pipe column are possibly damaged, and leakage point judgment is affected are solved. When the form of a leakage point needs to be determined due to abnormal rising of the casing pressure in the construction process, first-time ball throwing is performed firstly, rising of the casing pressure in the pressing process indicates that the oil pipe has the leakage point, if pressure can be stabilized, it indicates that no leakage point exists on the oil pipe, second-time ball throwing is performed at the moment, the pressure acts on the outer sleeve through the pressure transmission hole, and then the rubber sleeve piece is released; at the moment, the rubber sleeve piece and the packer rubber sleeve form a sealed space, if pressure is applied in the sealed space and pressure cannot be stabilized, the sealing of the packer fails, if pressure can be stabilized, the sealing of the packer is good, and a leakage point is caused by casing channeling.

Description

Technical Field

[0001] The present invention relates to the technical field of exploitation of unconventional oil and gas reservoirs such as petroleum and natural gas, and in particular to a tool and method for determining leakage points. Background Art

[0002] When oil and gas wells are fracturing, acidizing and other constructions with packers, the casing pressure sometimes rises abnormally. Once the casing pressure rises abnormally, the construction cannot be carried out. It is necessary to find out the cause of the abnormal increase in casing pressure and make corrections to complete the construction of the well. There are many reasons for the increase in casing pressure, such as leaks in the oil pipe, packer seal failure, casing layer leakage and other problems. To address the above problems that lead to the increase in casing pressure, the current conventional practice is to pull out the construction pipe string for inspection one by one. Not only is the construction workload large, but the shape of tools such as packers on the pipe string may be damaged during the process of pulling out the pipe string, affecting the judgment of the leak point form. Summary of the invention

[0003] The purpose of the present invention is to provide a tool and method for determining the form of leakage points, so as to solve the problems in the prior art of using the method of pulling out the construction pipe string for one-by-one inspection when the casing pressure rises, such as large construction workload and possible damage to the form of tools such as packers on the pipe string during the pulling out process, which affects the judgment of the leakage points.

[0004] In order to solve the above technical problems, the technical solution provided by the present invention is:

[0005] In a first aspect, the present invention provides a tool for determining the form of a leak, comprising: an upper joint, a body, a rubber cartridge assembly, a jacket, a first-stage ball, and a second-stage ball;

[0006] The upper joint is connected to the upper part of the body, the upper part of the upper joint is connected to the oil pipe, and the lower part of the body is provided with a packer;

[0007] The rubber cylinder assembly is provided with a rubber cylinder component, which is arranged below the upper joint and sleeved on one end of the body close to the upper joint, and the rubber cylinder component has a tendency to move in a direction away from the body;

[0008] The outer sleeve is arranged below the rubber cylinder assembly, the outer sleeve is sleeved outside the body and connected to the body by shear nails, a step structure is arranged on the top of the outer sleeve, one end of the rubber cylinder away from the upper joint is clamped on the step structure, and the step structure is used to restrain the rubber cylinder;

[0009] The body is provided with a pressure transmission hole, the pressure transmission hole is arranged downstream of the rubber cylinder, and the body is provided with a first ball seat and a second ball seat;

[0010] The second ball seat is arranged downstream of the pressure transmission hole, and the second ball seat is used to clamp the second-stage ball. After the second-stage ball is clamped in the second ball seat, after the oil pipe is pressurized by liquid, the pressure acts on the outer sleeve through the pressure transmission hole. When the pressure reaches the shearing force of the shear pin, the shear pin is cut, the outer sleeve moves downward, and the rubber cylinder part abuts against the inner wall of the casing after losing the constraint of the step structure.

[0011] The first ball seat is arranged downstream of the second ball seat, and the first ball seat is used for clamping the first-stage ball.

[0012] Furthermore, the inner diameter of the first ball seat is smaller than the inner diameter of the second ball seat.

[0013] Furthermore, the main body has a boss extending inwardly, the boss is arranged below the outer sleeve, and the boss is used to receive the outer sleeve after it has been lowered.

[0014] Furthermore, the rubber cartridge assembly also includes a rubber cartridge housing;

[0015] The rubber cylinder shell is connected to the bottom of the upper joint and is connected to the upper part of the rubber cylinder member.

[0016] Furthermore, the rubber cylinder is configured as a leather cup structure.

[0017] Furthermore, an extension tube extends upward from the top of the main body, and the extension tube is inserted into the lower part of the upper joint.

[0018] Furthermore, a sealing ring is provided between the extension tube and the body.

[0019] Furthermore, the material of the first-level ball is a fast-dissolving material.

[0020] Furthermore, the material of the second-level ball is a fast-dissolving material.

[0021] In a second aspect, the present invention provides a method for determining the form of a leak based on the tool for determining the form of a leak, comprising the following steps:

[0022] Step 1: When the casing pressure rises abnormally during the construction process and the leakage point needs to be determined, the first ball is dropped. When the first-level ball falls on the first seat, the pressure is pressed. The increase in casing pressure during the pressure pressing process indicates that there is a leakage point in the oil pipe;

[0023] Step 2: If the pressure can be stabilized, it means there is no leak on the oil pipe. At this time, the second ball is thrown. When the second-stage ball falls on the second ball seat, the rubber sleeve and the packer rubber sleeve form a sealed space. If the pressure cannot be stabilized in the sealed space, it means that the packer seal has failed. If the pressure can be stabilized, it means that the packer seal is good and the leak is caused by sleeve leakage.

[0024] Based on the above technical solutions, the technical effects that can be achieved by the present invention are:

[0025] The tool for determining the form of the leak point is put into the well together with the packer and other tools, and then lowered into the casing. The packer is first set. After the packer is set, fracturing, acidizing and other constructions are carried out according to the construction requirements. During the construction process, if the casing pressure rises abnormally and it is necessary to determine the form of the leak point, the first ball is dropped first, and the pressure is pressed when the first-level ball falls on the first ball seat. The rise in casing pressure during the pressure pressing process indicates that there is a leak point on the oil pipe. If the pressure can be stabilized, it means that there is no leak point on the oil pipe. At this time, the second ball is dropped, and the pressure is pressed when the second ball falls on the second-level ball seat. The pressure acts on the outer casing through the pressure transmission hole, and then the rubber sleeve is released. At this time, the rubber sleeve and the seal are The packer rubber cylinder forms a sealed space. If the pressure in the sealed space cannot be stabilized when pressurized, it means that the packer seal has failed. If the pressure can be stabilized, it means that the packer seal is good. The leakage is caused by casing leakage. In this way, the leakage forms can be eliminated one by one and finally the leakage form can be found. The present invention can determine the leakage form without lifting the tubing, effectively reducing the workload of finding the leakage form in the later stage and accelerating the efficiency of rectifying the leakage. It solves the problems of large construction workload in the prior art of lifting the construction tubing for one-by-one inspection when the casing pressure rises, and the possible damage to the shape of tools such as the packer on the tubing during the tubing lifting process, which affects the judgment of the leakage. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0027] Figure 1 To determine the leak point, tools and measures to transform the tools are put into the well together with the pipe string diagram;

[0028] Figure 2 A schematic diagram of the structure of a tool for determining the leakage point form provided by an embodiment of the present invention;

[0029] Figure 3 Schematic diagram of a tool for determining the leak point form for the first stage ball drop;

[0030] Figure 4 Schematic diagram of the rubber cartridge being activated after the second stage ball falls into the tool for determining the leak point form.

[0031] Icons: 31-upper joint; 32-body; 32a-pressure transmission hole; 32b-first ball seat; 32c-second ball seat; 32d-boss; 32e-extension tube; 33-rubber cylinder assembly; 33a-rubber cylinder member; 33b-rubber cylinder shell; 34-jacket; 34a-step structure; 34b-cavity; 35-first stage ball; 36-second stage ball; 37-shear nail; 38-sealing ring;

[0032] 1-safety joint; 2-hydraulic anchor; 3-tool to determine the leakage point; 4-packer; 5-oil pipe; 6-sliding sleeve; 7-casing; 8-cement ring; 9-sealing ball seat. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0034] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] Some embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0036] The present invention provides a tool for determining the form of leakage points, comprising: an upper joint 31, a body 32, a rubber cylinder assembly 33, a jacket 34, a first-stage ball 35 and a second-stage ball 36; the upper joint 31 is connected to the upper part of the body 32, the upper part of the upper joint 31 is connected to the oil pipe 5, and the lower part of the body 32 is provided with a packer 4; the rubber cylinder assembly 33 is provided with a rubber cylinder part 33a, the rubber cylinder part 33a is arranged below the upper joint 31, and is sleeved on one end of the body 32 close to the upper joint 31, and the rubber cylinder part 33a has a tendency to move in a direction away from the body 32; the jacket 34 is arranged below the rubber cylinder assembly 33, the jacket 34 is sleeved on the outside of the body 32, and is connected to the body 32 by shear nails 37, the top of the jacket 34 is provided with a step structure 34a, and the end of the rubber cylinder part 33a away from the upper joint 31 is clamped on the platform The step structure 34a is used to restrain the rubber cylinder part 33a; the body 32 is provided with a pressure transmission hole 32a, which is arranged downstream of the rubber cylinder part 33a, and the body 32 is provided with a first ball seat 32b and a second ball seat 32c; the second ball seat 32c is arranged downstream of the pressure transmission hole 32a, and the second ball seat 32c is used to clamp the second-level ball 36, and the second-level ball 36 is clamped in the second ball seat 32c. After the oil pipe 5 is pressurized by liquid, the pressure acts on the outer sleeve 34 through the pressure transmission hole 32a. When the pressure reaches the shearing force of the shear pin 37, the shear pin 37 is cut, and the outer sleeve 34 moves downward. After the rubber cylinder part 33a loses the constraint of the step structure 34a, it abuts against the inner wall of the sleeve 7; the first ball seat 32b is arranged downstream of the second ball seat 32c, and the first ball seat 32b is used to clamp the first-level ball 35.

[0037] The tool for determining the leakage point is put into the well together with the tools such as the packer 4, and then lowered into the casing 7. The packer 4 is first set. After the packer 4 is set, fracturing, acidizing and other constructions are carried out according to the construction requirements. In the process of construction, if the casing pressure rises abnormally and it is necessary to determine the leakage point, the first ball is thrown first, and the pressure is pressed when the first-level ball 35 falls on the first ball seat 32b. The rise of casing pressure during the pressure pressing process indicates that there is a leakage point on the oil pipe 5. If the pressure can be stabilized, it means that there is no leakage point on the oil pipe 5. At this time, the second ball is thrown, and the pressure is pressed when the second ball falls on the second-level ball seat 36. The pressure acts on the outer sleeve 34 through the pressure transmission hole 32a, and then the rubber cylinder part 33a is released. At this time, the rubber sleeve 33a and the rubber sleeve of the packer 4 form a sealed space. If the pressure in the sealed space cannot be stabilized, it means that the seal of the packer 4 has failed. If the pressure can be stabilized, it means that the seal of the packer 4 is good. The leakage point is caused by the casing leakage. In this way, the leakage point forms can be eliminated one by one, and finally the leakage point form is found. The present invention can determine the leakage point form without lifting the pipe string, effectively reducing the workload of finding the leakage point form in the later stage and accelerating the efficiency of rectifying the leakage point. It solves the problems of large construction workload in the prior art of lifting the construction pipe string for one-by-one inspection when the casing pressure rises, and the damage of the tool form of the packer 4 on the pipe string may be caused in the process of lifting the pipe string, which affects the judgment of the leakage point.

[0038] The following combination Figure 1-Figure 4 The structure and shape of the tool for determining the leakage point form provided in this embodiment are described in detail.

[0039] Regarding the shape and structure of the upper joint 31 and the body 32, in detail:

[0040] like Figure 2 As shown, the upper joint 31 is connected to the upper part of the body 32, and both the upper joint 31 and the body 32 are cylindrical structures. The upper part of the upper joint 31 is connected to the oil pipe 5, and the upper joint 31 is threadedly connected to the oil pipe 5. The lower part of the body 32 is connected to the packer 4. Specifically, an extension tube 32e extends upward from the top of the body 32, and the extension tube 32e is inserted into the lower part of the upper joint 31. The extension tube 32e is threadedly connected to the upper joint 31, and a sealing ring 38 is provided between the extension tube 32e and the body 32.

[0041] A pressure transmission hole 32a is provided on the main body 32, and a first ball seat 32b and a second ball seat 32c are arranged in the main body 32. The second ball seat 32c is arranged downstream of the pressure transmission hole 32a, and the second ball seat 32c is a seat structure extending inward from the inner wall of the main body 32. The diameter of the second-level ball 36 is larger than the inner diameter of the second ball seat 32c, and the second ball seat 32c is used for clamping and limiting the second-level ball 36; the first ball seat 32b is arranged downstream of the second ball seat 32c, and the first ball seat 32b is a seat structure extending inward from the inner wall of the main body 32, and the diameter of the first-level ball 35 is larger than the inner diameter of the first ball seat 32b, and the first ball seat 32b is used for clamping and limiting the first-level ball 35; wherein, the inner diameter of the first ball seat 32b is smaller than the inner diameter of the second ball seat 32c.

[0042] Regarding the shape and structure of the rubber cartridge assembly 33, in detail:

[0043] like Figure 2 As shown, the rubber cylinder assembly 33 includes a rubber cylinder member 33a and a rubber cylinder shell 33b. The rubber cylinder shell 33b is connected to the bottom of the upper joint 31, and is connected to the body 32, and is connected to the upper part of the rubber cylinder member 33a. The end of the rubber cylinder member 33a connected to the rubber cylinder shell 33b is sleeved on the body 32, and the pressure transmission hole 32a is set at the downstream of the rubber cylinder member 33a. The rubber cylinder member 33a has a tendency to move away from the body 32. Specifically, the rubber cylinder member 33a is vulcanized on the rubber cylinder shell 33b, which can be understood as being glued to the rubber cylinder shell 33b. The rubber cylinder member 33a is a leather cup structure, the small end of the bowl of the rubber cylinder member 33a faces upward and is fixed to the rubber cylinder shell 33b, and the large end of the bowl of the rubber cylinder member 33a faces downward. In order to limit the large end of the bowl, the present embodiment is provided with a jacket 34.

[0044] Regarding the shape and structure of the outer jacket 34, in detail:

[0045] The outer sleeve 34 is arranged below the rubber cylinder assembly 33. The outer sleeve 34 is sleeved on the outside of the main body 32 and connected to the main body 32 through shear nails 37. A step structure 34a is arranged on the top of the outer sleeve 34. The large end of the bowl mouth of the rubber cylinder part 33a is clamped on the step structure 34a. The step structure 34a is used to restrain the rubber cylinder part 33a so that the large end of the bowl mouth of the rubber cylinder part 33a is in a tightened state.

[0046] Specifically, the outer sleeve 34 is sleeved on the outside of the main body 32, and there is an annular cavity 34b between the outer sleeve 34 and the main body 32. The second-stage ball 36 is clamped in the second ball seat 32c. After the oil pipe 5 is pressurized by liquid, the pressure enters the cavity 34b through the pressure transmission hole 32a and acts on the outer sleeve 34. When the pressure reaches the shear force of the shear pin 37, the shear pin 37 is sheared, and the outer sleeve 34 moves downward. After the rubber cylinder part 33a loses the constraint of the step structure 34a, it abuts tightly against the inner wall of the casing 7; during the process of going down into the well, the outer sleeve 34 is used to limit the opening of the bowl mouth. When the outer sleeve 34 moves downward, the large end of the bowl mouth loses the restriction and returns to its original state.

[0047] In an optional embodiment, the main body 32 has a boss 32d extending inwardly. The boss 32d is arranged below the outer sleeve 34. The outer sleeve 34 finally falls on the boss 32d after descending. The boss 32d is used to receive the outer sleeve 34 after descending and to play a limiting role.

[0048] The method for determining the leakage point form based on the tool for determining the leakage point form provided in this embodiment includes the following steps:

[0049] Reference Figure 1 ,by Figure 1 The upper and lower positions in the figure are taken as the standard. The connection sequence of the tools on the oil pipe 5 is from top to bottom as follows: safety joint 1, hydraulic anchor 2, tool 3 for determining the leak point, packer 4, sleeve 6, ball seat 9. The tool 3 for determining the leak point is put into the well together with the tools such as safety joint 1, hydraulic anchor 2, packer 4, sleeve 6, ball seat 9, etc. When the tool is lowered to the designed position, the ball is thrown to seal the packer 4. After the packer 4 is sealed, the sleeve 6 is opened to prepare for construction. During the construction process, if the casing pressure (i.e., the pressure between the oil pipe 5 and the casing 7) rises abnormally, it means that there is a leak in the oil pipe 5, the seal of the packer 4 fails, and the casing 7 is layered. At this time, the leak point can be found by the tool for determining the leak point. First, the first-level ball 35 matching the tool is thrown. The first-level soluble ball is made of fast-soluble material. The first-level ball 35 enters the body 32 through the oil pipe 5. When the first-level ball 35 falls on the first ball seat 32b matching it, the oil pipe 5 is pressurized. Figure 3As shown, when the pressure rises to the set pressure, a pressure drop test is performed. If there is a pressure drop and the casing pressure increases at the same time, it means that there is a leak on the oil pipe 5. If there is no pressure drop, it means that there is no leak on the oil pipe 5 above the tool 3 for determining the leak. If there is no leak on the oil pipe 5, when the first-level ball 35 made of a fast-dissolving material dissolves to an outer diameter smaller than the inner diameter of the first ball seat 32b, the first-level ball 35 falls to the bottom of the well, and the second-level ball 36 is cast. The second-level soluble ball is made of a fast-dissolving material. When the second-level ball 36 falls on the second ball seat 32c that matches it in the tool, as shown in FIG. Figure 4 As shown, the pressure is continued to act on the outer sleeve 34 through the pressure transmission hole 32a. When the pressure reaches the shear force of the shear nail 37, the shear nail 37 is cut and the outer sleeve 34 moves downward. During the downward movement of the outer sleeve 34, the rubber sleeve part 33a on the rubber sleeve assembly 33 loses its constraint and is fitted with the casing 7. At this time, the rubber sleeve part 33a and the rubber sleeve on the packer 4 form a sealed space, and the pressure is transmitted to this sealed space through the pressure transmission hole 32a. When the pressure continues to reach the set pressure, if a pressure drop occurs, it means that there is a problem with the sealing of the packer 4, resulting in a leak. If no pressure drop occurs, it means that the sealing of the packer 4 is good, and it can be judged that there is a leak caused by layer leakage between the casing 7 and the cement ring 8. This method can be used to check the leakage type one by one and finally find the leakage type.

[0050] It should be noted that, since the packer 4 plays the role of protecting the casing 7 and isolating the reservoir during the on-site construction process, the sliding sleeve 6 below the packer 4 has been opened, and there is a liquid passage. The oil pipe 5 below the packer 4 is connected to the casing 7, and there is no need to consider the leakage point problem of the oil pipe 5 below the packer 4.

[0051] In this embodiment, the tool for determining the leakage point is lowered together with the construction string. When the casing pressure rises abnormally during construction with the packer 4 in the oil and gas well, the leakage point can be determined by starting the tool by dropping a ball without lifting the string. Compared with the prior art, this embodiment has the following advantages:

[0052] 1. By placing the leak point determination tool and the measure transformation tool into the well together, normal construction will not be affected.

[0053] 2. When the casing pressure rises abnormally during the construction process, the leakage point can be determined by throwing the ball without lifting the pipe string, which is highly operational.

[0054] 3. No need to run a leak finding string separately, which effectively reduces the workload of finding leak points in the later stage and speeds up the efficiency of leak point rectification.

[0055] 4. Direct leak detection on the construction string effectively avoids the well control risks and formation pollution problems that occur when the leak detection string is lowered alone.

[0056] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A tool for determining the form of a leak, characterized in that: include: An upper joint (31), a body (32), a rubber cylinder assembly (33), a jacket (34), a first-stage ball (35) and a second-stage ball (36); The upper joint (31) is connected to the upper part of the body (32), an oil pipe (5) is connected to the upper part of the upper joint (31), and a packer (4) is arranged below the body (32); The rubber cylinder assembly (33) is provided with a rubber cylinder component (33a), the rubber cylinder component (33a) is arranged below the upper joint (31), and is sleeved on one end of the body (32) close to the upper joint (31), and the rubber cylinder component (33a) has a tendency to move in a direction away from the body (32); The outer sleeve (34) is arranged below the rubber cylinder assembly (33), the outer sleeve (34) is sleeved on the outside of the body (32), and is connected to the body (32) through shear nails (37), a step structure (34a) is arranged on the top of the outer sleeve (34), and one end of the rubber cylinder component (33a) away from the upper joint (31) is clamped on the step structure (34a), and the step structure (34a) is used to restrain the rubber cylinder component (33a); The body (32) is provided with a pressure transmission hole (32a), the pressure transmission hole (32a) is arranged downstream of the rubber cylinder (33a), and the body (32) is provided with a first ball seat (32b) and a second ball seat (32c); The second ball seat (32c) is arranged downstream of the pressure transmission hole (32a), and the second ball seat (32c) is used to clamp the second-stage ball (36). The second-stage ball (36) is clamped in the second ball seat (32c). After the oil pipe (5) is pressurized by liquid, the pressure acts on the outer sleeve (34) through the pressure transmission hole (32a). When the pressure reaches the shearing force of the shear pin (37), the shear pin (37) is sheared, and the outer sleeve (34) moves downward. After the rubber sleeve (33a) loses the constraint of the step structure (34a), it abuts against the inner wall of the sleeve (7); The first ball seat (32b) is arranged downstream of the second ball seat (32c), and the first ball seat (32b) is used for clamping the first-stage ball (35).

2. The tool for determining the leakage point form according to claim 1, characterized in that: The inner diameter of the first ball seat (32b) is smaller than the inner diameter of the second ball seat (32c).

3. The tool for determining the leakage point form according to claim 1, characterized in that: The main body (32) is provided with a boss (32d) extending inwardly, the boss (32d) being arranged below the outer sleeve (34), and the boss (32d) being used to receive the outer sleeve (34) after descending.

4. The tool for determining the leakage point form according to claim 1, characterized in that: The rubber cartridge assembly (33) further comprises a rubber cartridge housing (33b); The rubber cylinder shell (33b) is connected to the bottom of the upper joint (31) and is connected to the upper part of the rubber cylinder member (33a).

5. The tool for determining the leakage point form according to claim 1, characterized in that: The rubber cylinder component (33a) is configured as a leather cup structure.

6. The tool for determining the leakage point form according to claim 1, characterized in that: An extension tube (32e) extends upward from the top of the main body (32), and the extension tube (32e) is inserted into the lower part of the upper joint (31).

7. The tool for determining the leakage point form according to claim 6, characterized in that: A sealing ring (38) is provided between the extension tube (32e) and the main body (32).

8. The tool for determining the leakage point form according to claim 1, characterized in that: The material of the first-stage ball (35) is a fast-dissolving material.

9. The tool for determining the leakage point form according to claim 1, characterized in that: The material of the second-stage ball (36) is a fast-dissolving material.

10. A method for determining the form of a leak based on the tool for determining the form of a leak as claimed in any one of claims 1 to 9, characterized in that: The following steps are involved: Step 1: When the casing pressure rises abnormally during the construction process and the leakage point needs to be determined, the first ball is thrown, and the pressure is pressed when the first-level ball (35) falls on the first seat. The increase in casing pressure during the pressing process indicates that there is a leakage point in the oil pipe (5); Step 2: If the pressure can be stabilized, it means that there is no leak on the oil pipe (5). At this time, the second ball is thrown. When the second-level ball (36) falls on the second ball seat (32c), the rubber sleeve (33a) and the rubber sleeve of the packer (4) form a sealed space. If the pressure cannot be stabilized in the sealed space, it means that the seal of the packer (4) has failed. If the pressure can be stabilized, it means that the seal of the packer (4) is good and the leak is caused by the sleeve leakage.

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