Push rod tool suitable for soluble bridge plug and push rod pipe string

Abstract

The utility model relates to a push rod, in particular to a push rod tool suitable for a soluble bridge plug and a push rod pipe string, and solves the problems of unstable success rate and low operation efficiency of the existing method for setting or semi-setting the bridge plug in advance. The push rod tool suitable for the soluble bridge plug can be connected with other parts through the external thread section to form a push rod pipe string, after the whole push rod pipe string is tripped into a well, the bridge plug subjected to setting or semi-setting is strongly impacted through the push rod tool, and even if the bridge plug is not damaged through one-time impact, the bridge plug can not be damaged. Multiple times of impact can be carried out by lifting the push rod pipe string, if the push rod tool is clamped into the bridge plug and cannot be lifted, potassium chloride can be injected into the bridge plug through the water tank and the water hole, so that the bridge plug is dissolved from the inside, and the success rate and the working efficiency are greatly improved by combining mechanical impact and chemical corrosion modes.

Description

Technical Field

[0001] The utility model relates to a push rod, in particular to a push rod tool and a push rod string applicable to a soluble bridge plug. Background Technique

[0002] With the successive development of tight gas, shale gas, tight oil, etc. by various oilfield operation units, in order to achieve large-displacement and large-volume fracturing of oil and gas wells, the pumping bridge plug perforation joint operation technology has emerged. Among them, the bridge plug, as an important component for wellbore plugging in this technology, exposes various problems during use, especially the problem that the bridge plug is prematurely set or semi-set before reaching the set depth when being lowered into the well. Currently, there is no professional tool for pushing the bridge plug. When the bridge plug is prematurely set or semi-set, there are usually two solutions. One is to use the mechanical impact method, that is, to drop an impact ball from the wellhead to impact the bridge plug to make it break and disintegrate; the other is to use the chemical corrosion method. Since the bridge plug is made of a material soluble in chloride ions, such as magnesium aluminum alloy, etc., substances containing chloride ions such as high-concentration potassium chloride can be pumped from the wellhead to accelerate its dissolution. However, both methods have their own limitations. Although the impact ball has high working efficiency, its success rate is unstable. After the impact ball impacts the bridge plug, the bridge plug may not be successfully disintegrated, and in this case, the blockage will be aggravated; while the method of pumping high-concentration potassium chloride from the wellhead to dissolve the bridge plug can completely break and disintegrate the bridge plug, but the potassium chloride injected into the well can only corrode from the plug surface of the bridge plug to the inside of the bridge plug slowly, with a long reaction time and low operation efficiency. Content of the Utility Model

[0003] The purpose of the utility model is to solve the problems of unstable success rate and low operation efficiency existing in the existing methods for dealing with the premature setting or semi-setting of the bridge plug, and to provide a push rod tool and a push rod string applicable to a soluble bridge plug.

[0004] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0005] A push rod tool applicable to a soluble bridge plug, characterized in that:

[0006] It includes a body;

[0007] A water tank is axially arranged inside the body, and both ends of the water tank are located inside the body;

[0008] An external thread section is arranged on the outer wall of the body, and the external thread section is located at the top end of the body;

[0009] A plurality of water holes are formed in the outer wall of the body. The water holes include an inlet water hole communicating with the water tank and an outlet water hole. The outlet water hole is located at the bottom end of the body, and its opening is biased towards the bottom end of the body; the inlet water hole is located between the external thread section and the outlet water hole, and its opening is biased towards the top end of the body.

[0010] Further, a push head is arranged at the bottom end of the body. The outlet water hole is located on the outer wall of the push head, and the push head is used to impact the bridge plug.

[0011] Further, the push head and the body are integrally arranged; there are three groups of inlet water holes, and the three groups of inlet water holes are evenly distributed along the axial direction between the push head and the external thread section. Each group of inlet water holes has two, and the two inlet water holes are arranged oppositely.

[0012] Further, there are three outlet water holes. One of the outlet water holes is located at the bottom end of the push head, and its center line coincides with the center line of the water tank. The other two outlet water holes are arranged oppositely on the outer wall of the push head.

[0013] Meanwhile, the present utility model also provides a push rod string applicable to a soluble bridge plug, which comprises a cable, a cable pony head, a CCL unit and a weight rod connected in sequence from top to bottom. The special feature lies in that: it further comprises the above-mentioned push rod tool applicable to the soluble bridge plug;

[0014] The lower end of the weight rod is connected to the external thread section at the top end of the push rod tool applicable to the soluble bridge plug through an internal thread.

[0015] Meanwhile, the present utility model also provides another push rod string applicable to a soluble bridge plug, which comprises a coiled tubing, a connector and a check valve connected in sequence from top to bottom. The special feature lies in that: it further comprises the above-mentioned push rod tool applicable to the soluble bridge plug;

[0016] The lower end of the check valve is connected to the external thread section at the top end of the push rod tool applicable to the soluble bridge plug through an internal thread.

[0017] Compared with the prior art, the beneficial effects of the present utility model are as follows:

[0018] (1) A push rod tool applicable to a soluble bridge plug provided by the present utility model can be connected with other components through the external thread section to form a push rod string. After the entire push rod string is lowered into the well, the seated or semi-seated bridge plug is vigorously impacted by the push rod tool. Even if the bridge plug cannot be destroyed by one impact, the push rod tool can be lifted to conduct multiple impacts. If the push rod tool gets stuck inside the bridge plug and cannot be lifted, potassium chloride can be injected into the bridge plug through the water tank and the water holes, causing the bridge plug to dissolve from the inside. By combining mechanical impact and chemical corrosion methods, the success rate and working efficiency are greatly improved. Moreover, the structure is simple, the processing cost is low, filling the blank of no professional tool to deal with the situation of the bridge plug being seated or semi-seated in advance.

[0019] (2) The push rod tool for soluble bridge plugs provided by the present utility model is provided with a push head, which increases the contact area with the bridge plug and speeds up the destruction efficiency.

[0020] (3) The water eyes in the push rod tool for soluble bridge plugs provided by the present utility model include an inlet water eye and an outlet water eye. The opening of the inlet water eye is biased towards the top of the body, so that the potassium chloride pumped from the wellhead can more easily flow into the water tank. And three groups of inlet water eyes are evenly distributed along the axial direction, and each group has two inlet water eyes and they are arranged oppositely, so as to ensure that more potassium chloride flows into the water tank. The outlet water eye is arranged on the outer wall of the push head. When the push head is inserted into the inside of the bridge plug, the potassium chloride that enters the water tank can just be injected into the inside of the bridge plug from the outlet water eye of the push head. Compared with the traditional method of directly injecting potassium chloride from the wellhead, the corrosion dissolution efficiency is improved. Description of the Drawings

[0021] Figure 1 is a cross-sectional view of a push rod tool for soluble bridge plugs of the present utility model;

[0022] Figure 2 is a three-dimensional structural schematic diagram of a push rod tool for soluble bridge plugs of the present utility model.

[0023] The description of the reference numerals is as follows:

[0024] 1 - body, 2 - water tank, 3 - external thread section, 4 - water eye, 41 - inlet water eye, 42 - outlet water eye; 5 - push head. Detailed Embodiment

[0025] The present utility model will be further described below in conjunction with the drawings and exemplary embodiments.

[0026] Refer to Figure 1 、 Figure 2 A push rod tool for soluble bridge plugs of the present utility model includes a body 1. A water tank 2 is axially opened inside the body 1, and the water tank 2 does not penetrate the body 1, and both ends of the water tank 2 are located inside the body 1. A plurality of water eyes 4 are opened on the outer wall of the body 1, including an inlet water eye 41 and an outlet water eye 42, and both the inlet water eye 41 and the outlet water eye 42 are communicated with the water tank 2. The water tank 2 serves to store potassium chloride and connect the inlet water eye 41 and the outlet water eye 42. An external thread section 3 is also provided on the outer wall of the body 1, and the external thread section 3 is located at the top of the body 1, which is convenient for the entire push rod tool to be connected with other components to form a push rod pipe string.

[0027] At the bottom of the body 1, there is a pushing head 5, which is used to impact the bridge plug. The pushing head 5 increases the contact area with the bridge plug, which is beneficial to accelerating the destruction efficiency. To ensure the connection stability between the pushing head 5 and the body 1 during the impact process, the pushing head 5 is integrally provided with the body 1.

[0028] There are three groups of inlet water eyes 41, and the three groups of inlet water eyes 41 are evenly distributed along the axial direction between the pushing head 5 and the external thread section 3. Each group of inlet water eyes 41 has two, and the two inlet water eyes 41 are arranged oppositely, and the openings of the inlet water eyes 41 are biased towards the top end of the body 1. In this way, the three groups of inlet water eyes 41 form a multi-stage structure, and the potassium chloride pumped from the wellhead can enter the water tank 2 more easily and in a larger amount.

[0029] There are three outlet water eyes 42. One of the outlet water eyes 42 is located at the bottom end of the pushing head 5, and the center line of this outlet water eye 42 coincides with the center line of the water tank 2. The other two outlet water eyes 42 are arranged oppositely on the outer wall of the pushing head 5. In this way, the three outlet water eyes 42 divide the potassium chloride entering the water tank 2 into three streams, ensuring that the inside of the bridge plug can be evenly injected with potassium chloride.

[0030] When the push rod tool is stuck inside the bridge plug and cannot be lifted, the potassium chloride pumped from the wellhead can enter the water tank 2 through the inlet water eyes 41 and be injected into the inside of the bridge plug through the outlet water eyes 42, accelerating the corrosion and dissolution efficiency.

[0031] Example 1 of the push rod string for soluble bridge plugs:

[0032] A push rod string for soluble bridge plugs in this embodiment includes a cable, a cable pony head, a CCL unit, a heavy rod, and the above-mentioned push rod tool for soluble bridge plugs, which are connected in sequence from top to bottom. The lower end of the heavy rod is connected to the external thread section 3 at the top end of the push rod tool for soluble bridge plugs through an internal thread. The CCL unit among them is a professional device for detecting depth, and the heavy rod is used for weight gain, making the inertia of the entire string greater. After lifting the same height, its gravitational potential energy is greater and the destruction effect is better.

[0033] The usage method of the push rod string for soluble bridge plugs in this embodiment is as follows:

[0034] S1 Lower the push rod string for soluble bridge plugs into the well.

[0035] S2 When the push rod tool for soluble bridge plugs touches the plug surface of the bridge plug, use the CCL unit to detect and determine the setting position of the bridge plug at this time.

[0036] On S3, lift the push rod tool applicable to the soluble bridge plug to more than 10 meters above the setting position of the bridge plug, then quickly lower it to impact the bridge plug, and repeat the lifting and impact for multiple times. If the bridge plug is successfully pushed off, perform step S5. If the push rod tool applicable to the soluble bridge plug gets stuck inside the bridge plug and cannot be lifted, perform step S4;

[0037] On S4, pump potassium chloride into the well from the wellhead. The potassium chloride enters the water tank 2 through the water inlet eye 41 and then is injected into the inside of the bridge plug through the water outlet eye 42 until the bridge plug dissolves;

[0038] On S5, recover the push rod string applicable to the soluble bridge plug from the wellhead to complete the pushing operation.

[0039] Example two of the push rod string applicable to the soluble bridge plug:

[0040] In this embodiment, a push rod string applicable to the soluble bridge plug includes a coiled tubing, a connector, a check valve, and the above-mentioned push rod tool applicable to the soluble bridge plug, which are connected in sequence from top to bottom. The lower end of the check valve is connected to the external thread section 3 at the top of the push rod tool applicable to the soluble bridge plug through an internal thread.

[0041] The usage method of the push rod string applicable to the soluble bridge plug in this embodiment is as follows:

[0042] On S1, lower the push rod string applicable to the soluble bridge plug into the well;

[0043] On S2, when the push rod tool applicable to the soluble bridge plug touches the plug surface of the bridge plug, determine the setting position of the bridge plug at this time;

[0044] On S3, lift the push rod tool applicable to the soluble bridge plug to more than 10 meters above the setting position of the bridge plug, then quickly lower it to impact the bridge plug, and repeat the impact for multiple times. If the bridge plug is successfully pushed off, perform step S5; If the push rod tool applicable to the soluble bridge plug gets stuck inside the bridge plug and cannot be lifted, perform step S4;

[0045] On S4, pump potassium chloride into the well from the wellhead. The potassium chloride enters the water tank 2 through the water inlet eye 41 and then is injected into the inside of the bridge plug through the water outlet eye 42 until the bridge plug dissolves;

[0046] On S5, recover the push rod string applicable to the soluble bridge plug from the wellhead to complete the pushing operation.

[0047] The above-described embodiments are only descriptions of the specific implementation manners of the present invention, and do not limit the scope of the present invention. Without departing from the design spirit of the present invention, various deformations and improvements made by those of ordinary skill in the art to the technical solutions of the present invention shall fall within the protection scope determined by the claims of the present invention.

Claims

1. A push rod tool applicable to a soluble bridge plug, characterized in that: It includes a body (1); A water tank (2) is axially provided inside the body (1), and both ends of the water tank (2) are located inside the body (1); An external thread section (3) is provided on the outer wall of the body (1), and the external thread section (3) is located at the top end of the body (1); A plurality of water holes (4) are provided on the outer wall of the body (1). The water holes (4) include an inlet water hole (41) communicated with the water tank (2) and an outlet water hole (42). The outlet water hole (42) is located at the bottom end of the body (1), and its opening is inclined towards the bottom end of the body (1); the inlet water hole (41) is located between the external thread section (3) and the outlet water hole (42), and its opening is inclined towards the top end of the body (1).

2. The push rod tool applicable to a soluble bridge plug according to claim 1, characterized in that: A push head (5) is provided at the bottom end of the body (1), and the outlet water hole (42) is located on the outer wall of the push head (5). The push head (5) is used to impact the bridge plug.

3. The push rod tool applicable to a soluble bridge plug according to claim 2, characterized in that: The push head (5) is integrally provided with the body (1); There are three groups of inlet water holes (41). The three groups of inlet water holes (41) are evenly distributed axially between the push head (5) and the external thread section (3). Each group of inlet water holes (41) has two, and the two inlet water holes (41) are arranged oppositely.

4. The push rod tool applicable to a soluble bridge plug according to claim 2, characterized in that: There are three outlet water holes (42). One of the outlet water holes (42) is located at the bottom end of the push head (5), and its center line coincides with the center line of the water tank (2). The other two outlet water holes (42) are arranged oppositely on the outer wall of the push head (5).

5. A push rod string applicable to a soluble bridge plug, comprising a cable, a cable master sub, a CCL unit, and a heavy rod connected in sequence from top to bottom, characterized in that: It also includes the push rod tool applicable to a soluble bridge plug according to any one of claims 1-4; The lower end of the weight rod is connected to the external thread section (3) at the top end of the push rod tool applicable to a soluble bridge plug through an internal thread.

6. A push rod string applicable to a soluble bridge plug, comprising a coiled tubing, a connector, and a check valve that are sequentially connected from top to bottom, and characterized in that: It also includes the push rod tool applicable to a soluble bridge plug according to any one of claims 1-4; The lower end of the check valve is connected to the external thread section (3) at the top end of the push rod tool applicable to a soluble bridge plug through an internal thread.

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