Rupture disc type toe end sliding sleeve and use method

Abstract

This invention belongs to the field of downhole tools for oil and gas fields, and specifically relates to a fracturing disc-type toe-end sliding sleeve and its usage method. A fracturing disc-type toe-end sliding sleeve includes: a sleeve body, which is a cylindrical structure with a through-flow channel at its center; an upper connector at the upper end and a lower connector at the lower end of the sleeve body; and several cylindrical holes arranged circumferentially in the middle, communicating with the flow channel. A fracturing disc, an adjusting ring, and a separator plate are sequentially installed from the inside out of each cylindrical hole. The adjusting ring is hollow, forming a closed space with the fracturing disc and the separator plate. A solid strong acid carrier is placed within this closed space, and solid strong acid is contained within the solid strong acid carrier. This invention utilizes the space formed by the adjusting ring, fracturing disc, and separator plate to place the solid strong acid carrier. After the fracturing disc ruptures, the solid strong acid reacts rapidly with water to generate strong acid, corroding the cement sheath and improving the connectivity between the sliding sleeve and the formation.

Description

Technical Field

[0001] The invention belongs to the field of downhole working tools in oil and gas fields, and in particular relates to a rupture disc type toe end sliding sleeve and a use method thereof. Background Art

[0002] The toe-end sliding sleeve is a tool used for connecting the wellbore and the formation without perforating in the first section of oil and gas horizontal wells and directional wells with casing completion. The opening of the sliding sleeve is achieved by holding back the pressure in the wellbore.

[0003] At present, after the existing toe sleeve is opened, it only connects the wellbore and the cement ring, and cannot reach the penetration depth of hydraulic sandblasting perforation and pyrotechnic perforation. When the surrounding near-wellbore pollution around the preset position of the toe sleeve is serious and the mud content of the reservoir is high, although the existing toe sleeve is opened and connects the wellbore and the cement ring, it is difficult to press the formation to carry out fracturing operations. Summary of the invention

[0004] In view of the above problems, the purpose of the present invention is to provide a rupture disc toe end sliding sleeve and a method of use. A solid strong acid carrier is placed in the space formed by the adjustment ring, the rupture disc and the isolation plate. After the rupture disc is ruptured, the solid strong acid reacts rapidly with water to generate strong acid, which corrodes the cement ring and improves the connectivity between the sliding sleeve and the formation.

[0005] The technical solution of the present invention is:

[0006] A rupture disc toe-end sliding sleeve comprises a sliding sleeve body, the sliding sleeve body is a cylindrical structure with a flow channel running through the center thereof, an upper joint is arranged at the upper port of the sliding sleeve body, a lower joint is arranged at the lower port of the sliding sleeve body, a plurality of cylindrical holes are circumferentially arranged in the middle of the sliding sleeve body, the cylindrical holes are connected with the flow channel, rupture discs, adjustment rings and isolation plates are sequentially installed in the cylindrical holes from the inside to the outside, the adjustment ring is hollow inside and forms a closed space with the rupture disc and the isolation plate, a solid strong acid carrier is arranged in the closed space, and a solid strong acid is arranged in the solid strong acid carrier.

[0007] A retaining spring groove is arranged on one side of the cylindrical hole away from the flow channel direction, a retaining spring is arranged in the retaining spring groove, the retaining spring is fixedly connected to the isolation plate, and limits and fixes the adjustment ring in the cylindrical hole.

[0008] The solid strong acid carrier is a hollow sealed glass shell, the closed space formed by the rupture piece, the adjustment ring and the isolation plate is filled with high temperature resistant isolation grease, and the solid strong acid carrier is located in the high temperature resistant isolation grease.

[0009] The rupture disc is a cylindrical structure, and an "O"-shaped sealing ring groove is designed on the side of the cylindrical structure. A "V"-shaped stress groove is set at one end of the two end surfaces of the cylindrical structure, and a crushing stress grid is set at the other end;

[0010] The rupture disc 3 forms a seal with the cylindrical hole through the "O"-ring in the "O"-ring groove.

[0011] One end of the rupture disc provided with a "V"-shaped stress groove 13 is close to the flow channel.

[0012] The upper joint is of oil pipe female thread type.

[0013] The lower joint is of oil pipe male thread type.

[0014] A method for using a rupture disc toe end sliding sleeve, using any of the rupture disc toe end sliding sleeves described above, the specific process is as follows:

[0015] Step 1: The rupture disc toe end sliding sleeve is lowered into the predetermined position;

[0016] Connect the rupture disc toe end sliding sleeve with the completion casing through the upper joint and the lower joint and run them together into the predetermined position to carry out cementing operation;

[0017] Step 2: Open the rupture disc toe end sliding sleeve;

[0018] The high pressure in the wellbore acts on the inner surface of the rupture disc to generate hydraulic force, and the adjustment ring and the retaining spring restrict the rupture disc from moving outward. When the pressure difference between the pressure in the wellbore and the pressure in the closed space composed of the adjustment ring, the rupture disc and the isolation plate is greater than the set rupture pressure of the rupture disc, the rupture disc is sheared and ruptured from the "V"-shaped stress groove position, and the high-pressure liquid in the wellbore enters the closed space composed of the adjustment ring, the rupture disc and the isolation plate. The solid strong acid carrier is ruptured under the high pressure at the moment of opening the rupture disc toe end sliding sleeve, and the solid strong acid reacts with water to generate strong acid, which will produce chemical reactions on the cement ring and the formation, and assist in establishing a connecting channel between the wellbore and the formation.

[0019] The technical effects of the present invention are as follows: 1. The present invention places a solid strong acid carrier in the space formed by the adjusting ring, the rupture disc and the isolation plate. After the rupture disc is broken, the solid strong acid reacts rapidly with water to generate strong acid, corrodes the cement ring, and improves the connectivity between the sleeve and the formation. 2. The present invention is provided with a "V"-shaped stress groove and a crushing stress grid through the rupture disc, which can achieve rapid fracturing of the rupture disc after pressurization in the pipe column, and is simple to operate, safe and reliable.

[0020] The following is a further description with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic structural diagram of a rupture disc type toe end sliding sleeve of the present invention.

[0022] Figure 2The figure is a schematic diagram of the rupture disk structure of a rupture disk type toe end sliding sleeve of the present invention.

[0023] Figure numerals: 1-sleeve body, 2-circlip, 3-rupture disc, 4-isolation plate, 5-adjusting ring, 6-"O"-shaped sealing ring, 7-solid strong acid carrier, 8-cylindrical hole, 9-circlip groove, 10-lower joint, 11-upper joint, 12-flow channel, 13-"V"-shaped stress groove, 14-crushing stress grid, 15 "O"-shaped sealing ring groove. DETAILED DESCRIPTION

[0024] Example 1

[0025] In order to overcome the problem that the existing toe end sliding sleeve cannot effectively connect the formation and carry out subsequent operations after opening when the near-well pollution is serious and the reservoir mud content is high, the present invention provides a Figure 1 A rupture disc toe end sliding sleeve and its use method are shown. The present invention uses a solid strong acid carrier to be placed in the space formed by an adjustment ring, a rupture disc and an isolation plate. After the rupture disc is ruptured, the solid strong acid reacts rapidly with water to generate strong acid, which corrodes the cement ring and improves the connectivity between the sliding sleeve and the formation.

[0026] like Figure 1 As shown, a rupture disc toe-end sliding sleeve comprises: a sliding sleeve body 1, the sliding sleeve body 1 is a cylindrical structure, the center of which is a through flow channel 12, the upper port of the sliding sleeve body 1 is provided with an upper joint 11, the lower port of the sliding sleeve body 1 is provided with a lower joint 10, a plurality of cylindrical holes 8 are circumferentially arranged in the middle of the sliding sleeve body 1, the cylindrical holes 8 are connected with the flow channel 12, the cylindrical holes 8 are sequentially installed with rupture discs 3, adjustment rings 5 ​​and isolation plates 4 from the inside to the outside, the adjustment ring 5 is hollow inside, and forms a closed space with the rupture disc 3 and the isolation plate 4, a solid strong acid carrier 7 is arranged in the closed space, and a solid strong acid is arranged in the solid strong acid carrier 7.

[0027] In the present invention, a solid strong acid carrier 7 is provided in a closed space formed by the rupture disc 3, the adjustment ring 5 and the isolation plate 4, and pressure is applied in the flow channel 12 penetrating the center of the sleeve body 1. After the rupture disc 3 is broken, the cylindrical hole 8 is connected to the flow channel 12, and the solid strong acid in the solid strong acid carrier 7 dissolves and reacts rapidly with water to generate strong acid, which corrodes the cement ring, thereby improving the connectivity between the sleeve and the formation.

[0028] Example 2

[0029] Preferably, on the basis of Example 1, in this embodiment, preferably, a retaining spring groove 9 is provided on the side of the cylindrical hole 8 away from the flow channel 12, and a retaining spring 2 is provided in the retaining spring groove 9, and the retaining spring 2 is fixedly connected to the isolation plate 4 and limits the adjustment ring 5 to be fixed in the cylindrical hole 8.

[0030] In actual use, the retaining spring 2 limits and fixes the adjusting ring 5 in the cylindrical hole 8 to prevent the adjusting ring from moving toward the flow channel 12 near the cylindrical hole 8 due to the pressure of the liquid column outside the sleeve body 1 and causing the rupture disk to rupture.

[0031] Preferably, the solid strong acid carrier 7 is a hollow sealed glass shell, the closed space formed by the rupture piece 3, the adjustment ring 5 and the isolation plate 4 is filled with high temperature resistant isolation grease, and the solid strong acid carrier 7 is located in the high temperature resistant isolation grease.

[0032] In actual use, the solid strong acid carrier 7 is a hollow sealed glass shell, which can ensure that the solid strong acid does not contact and react with other liquids when the rupture piece 3 is not broken. When the rupture piece 3 is broken, the hollow sealed glass shell is broken due to pressure changes, thereby releasing the solid strong acid; the high temperature resistant isolation grease can ensure the thermal stability of the solid strong acid in the solid strong acid carrier 7 when the rupture piece 3 is not broken.

[0033] Preferably, Figure 2 As shown, the rupture disc 3 is a cylindrical structure, an "O"-shaped sealing ring groove 15 is designed on the side of the cylindrical structure, a "V"-shaped stress groove 13 is provided at one end of the two end faces of the cylindrical structure, and a crushing stress grid 14 is provided at one end; the rupture disc 3 forms a seal with the cylindrical hole 8 through the "O"-shaped sealing ring 6 in the "O"-shaped sealing ring groove 15. The end of the rupture disc 3 provided with the "V"-shaped stress groove 13 is close to the flow channel 12.

[0034] In actual use, since the rupture disc 3 is provided with an "O"-shaped sealing ring groove 15, the "O"-shaped sealing ring 6 can ensure that the rupture disc 3 and the cylindrical hole 8 are sealed, preventing water from entering the closed space formed by the rupture disc 3, the adjustment ring 5 and the isolation plate 4 to cause the solid strong acid in the solid strong acid carrier 7 to react prematurely and fail. Since the rupture disc 3 is provided with a "V"-shaped stress groove 13 and a crushing stress grid 14, the rupture disc 3 can be quickly fractured after pressurization in the pipe column, which is simple to operate, safe and reliable.

[0035] Preferably, the upper joint 11 is a female threaded type for oil pipes, and the lower joint 10 is a male threaded type for oil pipes.

[0036] In actual use, the upper joint 1 is a female threaded buckle type of oil pipe, and the lower joint 10 is a male threaded buckle type of oil pipe. Due to the use of the oil pipe threaded buckle type, the present invention can be conveniently connected to the working pipe string without using a special conversion joint.

[0037] Example 3

[0038] Based on Example 2, a method for using a rupture disc toe end sliding sleeve is provided, using any rupture disc toe end sliding sleeve as described above, and the specific process is as follows:

[0039] Step 1: The rupture disc toe end sliding sleeve is lowered into the predetermined position;

[0040] The rupture disc toe end sliding sleeve is connected to the completion casing through the upper joint 11 and the lower joint 10 and lowered into a predetermined position together to perform cementing operation;

[0041] Step 2: Open the rupture disc toe end sliding sleeve;

[0042] When the pressure in the wellbore is high, the high pressure in the wellbore acts on the inner surface of the rupture disc to generate hydraulic force, and the adjusting ring 5 and the retaining spring 2 restrict the rupture disc 3 from moving outward. When the pressure difference between the pressure in the wellbore and the pressure in the enclosed space composed of the adjusting ring 5, the rupture disc 3 and the isolation plate 4 is greater than the set rupture pressure of the rupture disc 3, the rupture disc 3 is sheared and ruptured from the "V"-shaped stress groove 13, and the high-pressure liquid in the wellbore enters the enclosed space composed of the adjusting ring 5, the rupture disc 3 and the isolation plate 4. Under the high pressure at the moment when the rupture disc toe end sliding sleeve is opened, the glass shell of the solid strong acid carrier 7 is broken, and the solid strong acid reacts with water to generate strong acid, which will produce chemical reactions on the cement ring and the formation, and assist in establishing a connecting channel between the wellbore and the formation.

[0043] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A rupture disc toe end sliding sleeve, characterized in that: include: The sleeve body (1) is a cylindrical structure, the center of which is a flow channel (12) running through it, the upper end of the sleeve body (1) is provided with an upper joint (11), the lower end of the sleeve body (1) is provided with a lower joint (10), a plurality of cylindrical holes (8) are circumferentially provided in the middle of the sleeve body (1), the cylindrical holes (8) are connected to the flow channel (12), the cylindrical holes (8) are sequentially installed with a rupture disc (3), an adjustment ring (5) and an isolation plate (4) from the inside to the outside, the adjustment ring (5) is hollow inside, and forms a closed space with the rupture disc (3) and the isolation plate (4), the closed space is provided with a solid strong acid carrier (7), a solid strong acid is provided in the solid strong acid carrier (7), the solid strong acid carrier (7) is a hollow sealed glass shell, the closed space formed by the rupture piece (3), the adjustment ring (5) and the isolation plate (4) is filled with high temperature resistant isolation grease, the solid strong acid carrier (7) is located in the high temperature resistant isolation grease, the rupture piece (3) is a cylindrical structure, an "O"-shaped sealing ring groove (15) is designed on the side of the cylindrical structure, one end of the two end surfaces of the cylindrical structure is provided with a "V"-shaped stress groove (13), and the other end is provided with a crushing stress grid (14), and the end of the rupture piece (3) provided with the "V"-shaped stress groove (13) is close to the flow channel (12).

2. A rupture disc toe end sliding sleeve according to claim 1, characterized in that: A retaining spring groove (9) is provided on one side of the cylindrical hole (8) away from the flow channel (12), a retaining spring (2) is provided in the retaining spring groove (9), the retaining spring (2) is fixedly connected to the isolation plate (4), and limits the adjustment ring (5) to be fixed in the cylindrical hole (8).

3. The rupture disc toe end sliding sleeve according to claim 1, characterized in that: The rupture disc (3) forms a seal with the cylindrical hole (8) via the O-ring (6) in the O-ring groove (15).

4. The rupture disc toe end sliding sleeve according to claim 1, characterized in that: The upper joint (11) is of the oil pipe female thread type.

5. The rupture disc toe end sliding sleeve according to claim 1, characterized in that: The lower joint (10) is of the oil pipe male thread type.

6. The method for using any one of the rupture disc toe end sliding sleeves according to claims 1-5, characterized in that: The following steps are involved: Step 1: The rupture disc toe end sliding sleeve is lowered into the predetermined position; Connecting the rupture disc toe end sliding sleeve to the completion casing through an upper joint (11) and a lower joint (10), lowering them together into a predetermined position, and then performing cementing operations; Step 2: Open the rupture disc toe end sliding sleeve; When high pressure is built up in the wellbore, the high pressure in the wellbore acts on the inner surface of the rupture disc (3) to generate a hydraulic force, and the adjusting ring (5) and the retaining spring (2) restrict the rupture disc (3) from moving outward; when the pressure difference in the wellbore and the pressure in the closed space formed by the adjusting ring (5), the rupture disc (3) and the isolation plate (4) is greater than the set rupture pressure of the rupture disc (3), the rupture disc (3) is sheared and ruptured from the position of the "V"-shaped stress groove (13), and the high-pressure liquid in the wellbore enters the closed space formed by the adjusting ring (5), the rupture disc (3) and the isolation plate (4). Under the high pressure at the moment when the rupture disc toe end sliding sleeve is opened, the solid strong acid carrier (7) is ruptured, and the solid strong acid reacts with water to generate a strong acid, which reacts chemically with the cement ring and the formation, thereby assisting in establishing a connecting channel between the wellbore and the formation.

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