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

Abstract

The invention relates to a push rod, in particular to a push rod tool suitable for a soluble bridge plug, a push rod pipe string and a push operation method, and solves the problems of unstable success rate and low operation efficiency of an existing method for setting or semi-setting a bridge plug in advance. The push rod tool suitable for the soluble bridge plug can be connected with other components 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 be prevented from being 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, high-concentration 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 a mechanical impact mode and a chemical corrosion mode.

Description

Technical Field

[0001] The invention relates to a push rod, in particular to a push rod tool, a push rod pipe string and a pushing operation method suitable for a soluble bridge plug. Background Art

[0002] With the development of tight gas, shale gas, tight oil, etc. by various oilfield operators, in order to achieve large-volume and large-volume fracturing of oil and gas wells, the pumping bridge plug perforation joint operation technology has emerged. Among them, the bridge plug is an important component for the technology to achieve well plugging. Various problems are exposed during use, especially the problem that the bridge plug is set or semi-set in advance before reaching the set depth. At present, there is no professional tool for pushing the bridge plug. When the bridge plug is set or semi-set in advance, there are usually two solutions. One is to use a mechanical impact method, that is, to drop an impact ball from the wellhead to impact the bridge plug to break it and disintegrate it; the other is to use a chemical corrosion method, because the bridge plug is made of a material that is soluble in chloride ions, such as magnesium-aluminum alloy, etc., and a high-concentration potassium chloride or other chloride-containing substance can be pumped from the wellhead to accelerate its dissolution. However, both methods have their limitations. Although the impact ball has high working efficiency, its success rate is unstable. After the impact ball hits the bridge plug, the bridge plug may not be successfully disintegrated, which will aggravate the blockage. 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 slowly corrode from the surface of the bridge plug to the inside of the bridge plug, so the reaction time is long and the operation efficiency is low. Summary of the invention

[0003] The purpose of the present invention is to solve the problems of unstable success rate and low operation efficiency in the existing methods for handling premature setting or semi-setting of bridge plugs, and to provide a push rod tool, a push rod pipe string and a pushing operation method suitable for soluble bridge plugs.

[0004] In order to achieve the above-mentioned invention object, the present invention provides the following technical solutions:

[0005] A push rod tool suitable for a soluble bridge plug, the special features of which are: comprising a body;

[0006] A water tank is provided inside the body along the axial direction, and both ends of the water tank are located inside the body;

[0007] An external thread section is arranged on the outer wall of the body, and the external thread section is located at the top of the body;

[0008] A plurality of water holes are provided on the outer wall of the main body, and the water holes include a water inlet hole and a water outlet hole connected to the water tank, the water outlet hole is located at the bottom end of the main body, and its opening is biased toward the bottom end of the main body; the water inlet hole is located between the external thread section and the water outlet hole, and its opening is biased toward the top end of the main body.

[0009] Furthermore, a pusher head is provided at the bottom end of the main body, the water outlet hole is located on the outer wall of the pusher head, and the pusher head is used to impact the bridge plug.

[0010] Furthermore, the pusher head is integrally arranged with the body; the water inlet eyes are arranged in three groups, and the three groups of water inlet eyes are evenly distributed axially between the pusher head and the external thread section, each group of water inlet eyes has two water inlet eyes, and the two water inlet eyes are arranged opposite to each other.

[0011] Furthermore, there are three water outlet holes, one of which is located at the bottom of the pusher head, and its center line coincides with the center line of the water tank, and the other two water outlet holes are relatively arranged on the outer wall of the pusher head.

[0012] Meanwhile, the present invention also provides a push rod pipe string suitable for a soluble bridge plug, comprising a cable, a cable bridle, a CCL unit and a weighting rod connected in sequence from top to bottom, and the special feature thereof is that: it also includes the above-mentioned push rod tool suitable for a soluble bridge plug;

[0013] The lower end of the weight rod is connected to the external thread section at the top end of the push rod tool suitable for the soluble bridge plug through an internal thread.

[0014] At the same time, the present invention also provides a pushing operation method applicable to a soluble bridge plug, based on the above-mentioned push rod pipe string applicable to a soluble bridge plug, which is special in that it includes the following steps:

[0015] S1 puts a push rod string suitable for a soluble bridge plug into the well;

[0016] S2 When the push rod tool suitable for the soluble bridge plug contacts the plug surface of the bridge plug, the CCL unit is used to detect and determine the setting position of the bridge plug at this time;

[0017] S3: lift the push rod tool suitable for the soluble bridge plug to more than 10 meters above the bridge plug setting position, then quickly lower it to hit the bridge plug, repeat the lifting and hitting multiple times, if the bridge plug is successfully pushed out, execute step S5, if the push rod tool suitable for the soluble bridge plug is stuck inside the bridge plug and cannot be lifted, execute step S4;

[0018] S4 pumps potassium chloride from the wellhead into the well. The potassium chloride enters the water tank through the water inlet eye and is then injected into the bridge plug through the water outlet eye until the bridge plug dissolves.

[0019] S5 retrieves the push rod string suitable for the soluble bridge plug from the wellhead to complete the pushing operation.

[0020] Meanwhile, the present invention also provides another push rod pipe string suitable for soluble bridge plugs, comprising a continuous oil pipe, a connector and a check valve connected in sequence from top to bottom, and the special feature thereof is that: it also comprises the above-mentioned push rod tool suitable for soluble bridge plugs;

[0021] The lower end of the check valve is connected to the external thread section at the top end of a push rod tool suitable for a soluble bridge plug through an internal thread.

[0022] The present invention also provides another method for pushing a soluble bridge plug, based on the above-mentioned another push rod pipe string suitable for a soluble bridge plug, which is special in that it includes the following steps:

[0023] S1 puts a push rod string suitable for a soluble bridge plug into the well;

[0024] S2 When the push rod tool suitable for the soluble bridge plug contacts the plug surface of the bridge plug, the setting position of the bridge plug is determined;

[0025] S3: lift the push rod tool suitable for the soluble bridge plug to more than 10 meters above the bridge plug setting position, then quickly lower it to hit the bridge plug, repeat the impact multiple times, if the bridge plug is successfully pushed out, execute step S5; if the push rod tool suitable for the soluble bridge plug is stuck inside the bridge plug and cannot be lifted up, execute step S4;

[0026] S4 pumps potassium chloride from the wellhead into the well. The potassium chloride enters the water tank through the water inlet eye and is then injected into the bridge plug through the water outlet eye until the bridge plug dissolves.

[0027] S5 retrieves the push rod string suitable for the soluble bridge plug from the wellhead to complete the pushing operation.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] (1) The push rod tool suitable for soluble bridge plugs provided by the present invention can be connected with other components through an external threaded section to form a push rod pipe string. After the entire push rod pipe string is lowered into the well, the push rod tool is used to strongly impact the bridge plug after it is set or semi-set. Even if the bridge plug cannot be destroyed by one impact, it can be hit multiple times by lifting the push rod tool. If the push rod tool is stuck inside the bridge plug and cannot be lifted up, potassium chloride can be injected into the bridge plug through a water trough and a water hole to dissolve the bridge plug from the inside. The combination of mechanical impact and chemical corrosion greatly improves the success rate and work efficiency. In addition, the structure is simple and the processing cost is low, filling the gap of the lack of professional tools to deal with the situation of premature setting or semi-setting of the bridge plug.

[0030] (2) The push rod tool suitable for the soluble bridge plug provided by the present invention is provided with a push head, which increases the contact area with the bridge plug and accelerates the destruction efficiency.

[0031] (3) The water eye in the push rod tool suitable for soluble bridge plug provided by the present invention comprises a water inlet eye and a water outlet eye, wherein the opening of the water inlet eye is biased toward the top of the main body, so that the potassium chloride pumped from the wellhead can flow into the water tank more easily, and the water inlet eye is evenly distributed in three groups along the axial direction, each group of water inlet eyes has two and are arranged oppositely, so that more potassium chloride can be ensured to flow into the water tank, and the water outlet eye is arranged on the outer wall of the push head. When the push head is inserted into the bridge plug, the potassium chloride entering the water tank can be injected into the bridge plug from the water outlet eye of the push head. Compared with the traditional method of directly injecting potassium chloride from the wellhead, the corrosion dissolution efficiency is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a cross-sectional view of a push rod tool suitable for a soluble bridge plug according to the present invention;

[0033] Figure 2 It is a schematic diagram of the three-dimensional structure of the push rod tool suitable for the soluble bridge plug according to the present invention.

[0034] The following are the descriptions of the reference numerals:

[0035] 1-main body, 2-water tank, 3-external thread section, 4-water eye, 41-water inlet eye, 42-water outlet eye; 5-push head. DETAILED DESCRIPTION

[0036] The present invention is further described below in conjunction with the accompanying drawings and exemplary embodiments.

[0037] Reference Figure 1 , Figure 2 A push rod tool suitable for a soluble bridge plug of the present invention comprises a body 1, a water tank 2 is axially provided 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 holes 4 are provided on the outer wall of the body 1, including a water inlet water hole 41 and a water outlet water hole 42, and the water inlet water hole 41 and the water outlet water hole 42 are both connected to the water tank 2, and the water tank 2 plays the role of storing potassium chloride and connecting the water inlet water hole 41 and the water outlet water hole 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, so as to facilitate the entire push rod tool to be connected with other components to form a push rod pipe string.

[0038] A push head 5 is provided at the bottom end of the main body 1, which is used to impact the bridge plug. The push head 5 increases the contact area with the bridge plug, which is beneficial to accelerate the destruction efficiency. In order to ensure the connection stability between the push head 5 and the main body 1 during the impact process, the push head 5 is integrally arranged with the main body 1.

[0039] There are three groups of water inlet eyes 41, which are evenly distributed along the axial direction between the push head 5 and the external thread section 3. Each group of water inlet eyes 41 has two water inlet eyes 41, and the two water inlet eyes 41 are arranged opposite to each other, and the openings of the water inlet eyes 41 are biased toward the top of the main body 1. In this way, the three groups of water inlet eyes 41 form a multi-stage structure, and the potassium chloride pumped in from the wellhead can enter the water tank 2 more easily and more.

[0040] There are three water outlet holes 42, one of which is located at the bottom of the push head 5, and the center line of the water outlet hole 42 coincides with the center line of the water tank 2, and the other two water outlet holes 42 are relatively arranged on the outer wall of the push head 5. In this way, the three water outlet holes 42 divide the potassium chloride entering the water tank 2 into three streams, ensuring that potassium chloride can be evenly injected into the bridge plug.

[0041] When the push rod tool is stuck in the bridge plug and cannot be lifted up, potassium chloride pumped from the wellhead can enter the water tank 2 from the water inlet hole 41 and be injected into the bridge plug through the water outlet hole 42 to accelerate the corrosion dissolution efficiency.

[0042] Embodiment 1 of a push rod pipe string suitable for a soluble bridge plug:

[0043] The push rod pipe string suitable for soluble bridge plugs in this embodiment includes cables, cable bridles, CCL units, weighting rods and the above-mentioned push rod tools suitable for soluble bridge plugs connected in sequence from top to bottom, and the lower end of the weighting rod is connected to the external threaded section 3 at the top of the push rod tool suitable for soluble bridge plugs through an internal thread.

[0044] The CCL unit is a professional device for detecting depth, and the weight rod is used to increase the weight, making the inertia of the entire pipe string greater. After being lifted to the same height, its gravitational potential energy is greater and the destructive effect is better.

[0045] At the same time, this embodiment also provides a pushing operation method applicable to a soluble bridge plug, based on the above-mentioned push rod pipe string applicable to a soluble bridge plug, comprising the following steps:

[0046] S1 puts a push rod string suitable for a soluble bridge plug into the well;

[0047] S2 When the push rod tool suitable for the soluble bridge plug contacts the plug surface of the bridge plug, the CCL unit is used to detect and determine the setting position of the bridge plug at this time;

[0048] S3: lift the push rod tool suitable for the soluble bridge plug to more than 10 meters above the bridge plug setting position, then quickly lower it to hit the bridge plug, repeat the lifting and hitting multiple times, if the bridge plug is successfully pushed out, execute step S5, if the push rod tool suitable for the soluble bridge plug is stuck inside the bridge plug and cannot be lifted, execute step S4;

[0049] S4: Potassium chloride is pumped into the well from the wellhead. The potassium chloride enters the water tank 2 through the water inlet hole 41 and then is injected into the bridge plug through the water outlet hole 42 until the bridge plug is dissolved.

[0050] S5 retrieves the push rod string suitable for the soluble bridge plug from the wellhead to complete the pushing operation.

[0051] Embodiment 2 of a push rod pipe string suitable for a soluble bridge plug:

[0052] In this embodiment, the push rod pipe string suitable for soluble bridge plugs includes a continuous oil pipe, a connector, a check valve and the above-mentioned push rod tool suitable for soluble bridge plugs connected in sequence from top to bottom. The lower end of the check valve is connected to the external threaded section 3 at the top of the push rod tool suitable for soluble bridge plugs through an internal thread.

[0053] At the same time, this embodiment also provides a pushing operation method applicable to a soluble bridge plug, based on the above-mentioned push rod pipe string applicable to a soluble bridge plug, comprising the following steps:

[0054] S1 puts a push rod string suitable for a soluble bridge plug into the well;

[0055] S2 When the push rod tool suitable for the soluble bridge plug contacts the plug surface of the bridge plug, the setting position of the bridge plug is determined;

[0056] S3: lift the push rod tool suitable for the soluble bridge plug to more than 10 meters above the bridge plug setting position, then quickly lower it to hit the bridge plug, repeat the impact multiple times, if the bridge plug is successfully pushed out, execute step S5; if the push rod tool suitable for the soluble bridge plug is stuck inside the bridge plug and cannot be lifted up, execute step S4;

[0057] S4: Potassium chloride is pumped into the well from the wellhead. The potassium chloride enters the water tank 2 through the water inlet hole 41 and then is injected into the bridge plug through the water outlet hole 42 until the bridge plug is dissolved.

[0058] S5 retrieves the push rod string suitable for the soluble bridge plug from the wellhead to complete the pushing operation.

[0059] The embodiments described above are merely descriptions of specific implementation methods of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A push rod tool suitable for a soluble bridge plug, characterized in that: The invention comprises a body (1); A water tank (2) is provided inside the body (1) along the axial direction, 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 of the body (1); A plurality of water holes (4) are provided on the outer wall of the body (1), the water holes (4) comprising a water inlet hole (41) and a water outlet hole (42) which are connected to the water tank (2), the water outlet hole (42) being located at the bottom end of the body (1), and its opening is biased toward the bottom end of the body (1); the water inlet hole (41) is located between the external thread section (3) and the water outlet hole (42), and its opening is biased toward the top end of the body (1).

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

3. The push rod tool suitable for soluble bridge plug according to claim 2, characterized in that: The pusher head (5) is integrally arranged with the body (1); The water inlet eyes (41) are provided in three groups, and the three groups of water inlet eyes (41) are evenly distributed between the push head (5) and the external thread section (3) along the axial direction, and each group of water inlet eyes (41) has two water inlet eyes (41), and the two water inlet eyes (41) are arranged opposite to each other.

4. The push rod tool suitable for soluble bridge plug according to claim 2, characterized in that: There are three water outlet holes (42), one of which is located at the bottom of the pusher head (5) and has its center line coincident with the center line of the water tank (2), and the other two water outlet holes (42) are arranged on the outer wall of the pusher head (5) in a relative manner.

5. A push rod pipe string suitable for a soluble bridge plug, comprising a cable, a cable bridle, a CCL unit and a weighting rod connected in sequence from top to bottom, characterized in that: Also includes a push rod tool suitable for a soluble bridge plug as described in any one of claims 1 to 4; The lower end of the weight rod is connected to the external thread section (3) at the top of a push rod tool suitable for a soluble bridge plug via an internal thread.

6. A method for pushing a soluble bridge plug, based on the push rod string for a soluble bridge plug according to claim 5, characterized in that: The following steps are involved: S1 puts a push rod string suitable for a soluble bridge plug into the well; S2 When the push rod tool suitable for the soluble bridge plug contacts the plug surface of the bridge plug, the CCL unit is used to detect and determine the setting position of the bridge plug at this time; S3: lift the push rod tool suitable for the soluble bridge plug to more than 10 meters above the bridge plug setting position, then quickly lower it to hit the bridge plug, repeat the lifting and hitting multiple times, if the bridge plug is successfully pushed out, execute step S5, if the push rod tool suitable for the soluble bridge plug is stuck inside the bridge plug and cannot be lifted, execute step S4; S4: Potassium chloride is pumped into the well from the wellhead. The potassium chloride enters the water tank (2) through the water inlet hole (41) and is then injected into the bridge plug through the water outlet hole (42) until the bridge plug is dissolved. S5 retrieves the push rod string suitable for the soluble bridge plug from the wellhead to complete the pushing operation.

7. A push rod pipe string suitable for a soluble bridge plug, comprising a continuous oil pipe, a connector and a check valve connected in sequence from top to bottom, characterized in that: Also includes a push rod tool suitable for a soluble bridge plug as described in any one of claims 1 to 4; The lower end of the check valve is connected to the external thread section (3) at the top end of a push rod tool suitable for a soluble bridge plug via an internal thread.

8. A method for pushing a soluble bridge plug, based on the push rod string for a soluble bridge plug according to claim 7, characterized in that: The following steps are involved: S1 puts a push rod string suitable for the soluble bridge plug into the well; S2 When the push rod tool suitable for the soluble bridge plug contacts the plug surface of the bridge plug, the setting position of the bridge plug is determined; S3: lifting the push rod tool suitable for the soluble bridge plug to more than 10 meters above the bridge plug setting position, and then quickly lowering it to impact the bridge plug, repeating the impact multiple times. If the bridge plug is successfully pushed out, executing step S5; If the push rod tool suitable for the soluble bridge plug is stuck inside the bridge plug and cannot be lifted up, step S4 is executed; S4: Potassium chloride is pumped into the well from the wellhead. The potassium chloride enters the water tank (2) through the water inlet hole (41) and is then injected into the bridge plug through the water outlet hole (42) until the bridge plug is dissolved. S5 retrieves the push rod string suitable for the soluble bridge plug from the wellhead to complete the pushing operation.

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