CN112228026A

CN112228026A - A dissolving time delay toe end sliding sleeve

Info

Publication number: CN112228026A
Application number: CN201910633918.2A
Authority: CN
Inventors: 钱杰; 张卫平; 沈泽俊; 童征
Original assignee: Petrochina Co Ltd
Current assignee: Petrochina Co Ltd
Priority date: 2019-07-15
Filing date: 2019-07-15
Publication date: 2021-01-15

Abstract

The invention discloses a dissolving type time-delay toe end sliding sleeve which comprises an outer working barrel and an inner working barrel, wherein an annular cavity is formed between the outer working barrel and the inner working barrel, a sliding sleeve (4) and a dissolving time-delay ring (6) are sleeved between the outer working barrel and the inner working barrel, a first inner through hole (11) and a second inner through hole (12) are formed in the side wall of the inner working barrel, an outer through hole (13) is formed in the side wall of the outer working barrel, the sliding sleeve (4) can block the first inner through hole (11) and the outer through hole (13), a crushing disc (9) is hermetically connected in the second inner through hole (12), pressure liquid in the inner working barrel can crush the crushing disc (9) and enter the annular cavity, and the dissolving time-delay ring (6) is made of metal or alloy capable of being dissolved in water. The dissolving type time-delay toe end sliding sleeve can be dissolved in water and made of metal or alloy as a time-delay means, is not influenced by high temperature in the well, and has the advantages of simple and convenient processing and assembly, easy control of time delay time and the like.

Description

Dissolving type time-delay toe end sliding sleeve

Technical Field

The invention relates to the field of oil extraction equipment, in particular to a dissolving type time-delay toe end sliding sleeve.

Background

The existing bridge plug layered fracturing technology is widely applied to oil well fracturing due to multiple advantages. However, prior to fracturing, bridge plug technology relies primarily on coiled tubing operations or crawler tractions to perform the first layer of perforations to open pumping channels. The toe end sliding sleeve tool can be used for opening the toe end sliding sleeve only by suppressing pressure at a well mouth without operating through a perforation or other tools after the well cementation cement paste is solidified on the premise of not changing the existing well cementation process, and directly performing fracturing operation and assisting other downhole tools such as a logging instrument and the like to enter the well bottom. Compared with a continuous oil pipe transmission perforation mode, the toe end sliding sleeve has the advantages of high operation timeliness, low cost, small risk, unlimited operation depth and the like.

At present, most of toe end sliding sleeves used in oil field operation are opened in a rupture disk rupture mode, most of the toe end sliding sleeves do not have a time delay function, and the requirement of pressure test of sleeves in oil fields cannot be met. Chinese patent CN109339757A, published as 2019, 2.15.A "delay sliding sleeve" is introduced, in which a delay mechanism uses a pressure-limiting valve and a flow control valve to control hydraulic oil sealed in an inner cavity of the sliding sleeve, and the flow of the hydraulic oil is controlled under the action of the pressure of the liquid in the sleeve to perform a delay function. Chinese patent CN207999237U, published as 2018, 10.23.A pressure-testable toe end sliding sleeve is introduced, which can prevent well cementing cement from fixing the sliding sleeve in the well cementing process, and the movement speed of the inner sliding sleeve is constant by controlling the flow speed of grease sealed in the sliding sleeve, thereby playing a time delay role. Both the two patents adopt the purpose of controlling the flow speed or flow of the hydraulic oil sealed in the sliding sleeve to achieve the time delay, and have the problems that the burst pressure of the rupture disk conflicts with the pressure testing pressure of a well mouth and a sleeve, the time delay is influenced by more factors and is difficult to control, and the like. Chinese patent CN207048728U, published as 2018, 2.27, describes a sleeve toe sliding sleeve controlled by liquid pulse, which receives pressure pulse signals transmitted from the ground through a pressure sensor placed on the sliding sleeve, detonates the shaped charge mounted on the sliding sleeve when conditions are met to introduce the liquid in the sleeve into the toe sliding sleeve, and pushes the inner sliding sleeve to move to open the fracturing channel. This patent has adopted the means that automatically controlled mode realized the time delay, has the some that can open at any time according to the ground requirement, but electronic components in the pit easily became invalid under the high temperature condition, has the very big risk that leads to toe end sliding sleeve to become invalid.

Disclosure of Invention

In order to solve the problem that the existing time-delay sliding sleeve is not easy to control the time delay, the invention provides a soluble time-delay toe end sliding sleeve which can be dissolved in metal or alloy of water as a time delay means, is not influenced by high temperature in the pit and has the advantages of simple and convenient processing and assembly, easy control of time delay and the like.

The technical scheme adopted by the invention for solving the technical problems is as follows: a dissolving type time-delay toe end sliding sleeve comprises an outer working barrel and an inner working barrel, wherein the outer working barrel is sleeved outside the inner working barrel, an annular cavity is formed between the outer working barrel and the inner working barrel, a sliding sleeve and a dissolving time-delay ring are sleeved between the outer working barrel and the inner working barrel and are arranged at intervals along the axis direction of the inner working barrel, a first inner through hole and a second inner through hole are arranged in the side wall of the inner working barrel and are arranged at intervals along the axis direction of the inner working barrel, the dissolving time-delay ring is positioned between the first inner through hole and the second inner through hole, an outer through hole is arranged in the side wall of the outer working barrel, the first inner through hole corresponds to the outer through hole in position, the sliding sleeve can block the first inner through hole and the outer through hole, the sliding sleeve can move along the axis direction of the inner working barrel, a crushing disc is connected in the second inner through hole in a sealing manner, the pressure liquid in the inner working barrel can break the crushing disc and enter the annular cavity, and the dissolution delay ring is made of metal or alloy which can be dissolved in water.

The outer working barrel comprises an upper joint, an upper outer sleeve and a lower outer sleeve which are sequentially and hermetically connected along the axis direction, and an outer through hole is positioned in the side wall of the upper outer sleeve.

The inner working barrel comprises a central tube and a lower joint which are sequentially and hermetically connected along the axis direction, one end of the central tube is fixedly and hermetically connected with the upper joint, and one end of the lower outer sleeve is fixedly and hermetically connected with the lower joint.

The first inner through hole is located in the side wall of the central tube, the second inner through hole is located in the side wall of the lower joint, and the diameter of the first inner through hole is equal to that of the outer through hole.

The sliding sleeve is in clearance fit or transition fit with the upper outer sleeve, the sliding sleeve is in clearance fit or transition fit with the central tube, and the length of the sliding sleeve is larger than the diameter of the first inner through hole.

The sliding sleeve is connected with the upper outer sleeve in a sealing mode, the sliding sleeve is connected with the central pipe in a sealing mode, the sliding sleeve is made of metal or alloy capable of being dissolved in water, a shearing pin is connected between the sliding sleeve and the central pipe, and the outer peripheral face and the inner peripheral face of the sliding sleeve are both provided with waterproof coatings.

A first plug is arranged in the first inner through hole, a second plug is arranged in the outer through hole, and the first plug and the second plug are both water-insoluble paste.

The dissolution delay ring is in clearance fit or transition fit with the lower outer sleeve, the dissolution delay ring is in clearance fit or transition fit with the central tube, the dissolution delay ring is in sealing connection with the lower outer sleeve, and the dissolution delay ring is in sealing connection with the central tube.

One end of the second inner through hole is communicated with the inside of the lower connector, the other end of the second inner through hole is communicated with the annular cavity, and a cylindrical compression cap is fixedly sleeved in the second inner through hole.

The crushing disc is located on the inner side of the second inner through hole, the pressing cap is located on the outer side of the second inner through hole, the crushing disc is abutted to the pressing cap, and the section of the crushing disc is in a crescent shape protruding towards the pressing cap.

The invention has the beneficial effects that: the dissolving type time-delay toe end sliding sleeve can be dissolved in water and made of metal or alloy as a time-delay means, is not influenced by high temperature in the well, and has the advantages of simple and convenient processing and assembly, easy control of time delay time and the like. The method has important significance for reducing construction difficulty and fracturing cost of fracturing split layers.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate embodiments of the invention and, together with the description, serve to explain the invention and not to limit the invention.

Fig. 1 is a schematic structural view of the dissolution type time-delay toe end sliding sleeve of the invention.

Fig. 2 is an enlarged schematic view of the sliding sleeve in fig. 1.

1. An upper joint; 2. putting an outer sleeve; 3. a central tube; 4. a sliding sleeve; 5. shearing the pin; 6. dissolving the time delay ring; 7. a lower outer sleeve; 8. a compression cap; 9. crushing the disc; 10. a lower joint; 11. a first inner through hole; 12. a second inner through hole; 13. an outer through hole;

301. a first plug; 302. a second plug.

Detailed Description

It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present invention will be described in detail below with reference to the embodiments with reference to the attached drawings.

A dissolving type time-delay toe end sliding sleeve comprises an outer working barrel and an inner working barrel, wherein the outer working barrel is sleeved outside the inner working barrel, an annular cavity is formed between the outer working barrel and the inner working barrel, a sliding sleeve 4 and a dissolving time-delay ring 6 are sleeved between the outer working barrel and the inner working barrel, the sliding sleeve 4 and the dissolving time-delay ring 6 are arranged at intervals along the axial direction of the inner working barrel, a first inner through hole 11 and a second inner through hole 12 are arranged in the side wall of the inner working barrel, the first inner through hole 11 and the second inner through hole 12 are also arranged at intervals along the axial direction of the inner working barrel, the dissolving time-delay ring 6 is positioned between the first inner through hole 11 and the second inner through hole 12, an outer through hole 13 is arranged in the side wall of the outer working barrel, the first inner through hole 11 corresponds to the position of the outer through hole 13, the sliding sleeve 4 can block the first inner through hole 11 and the outer through hole 13, and the sliding sleeve 4 can move along the axial direction of the inner, the second inner through hole 12 is internally and hermetically connected with a crushing disc 9, pressure liquid in the inner working barrel can crush the crushing disc 9 and enters the annular cavity through the second inner through hole 12, and the dissolution delay ring 6 is made of metal or alloy which can be dissolved in water, as shown in fig. 1.

In the embodiment, the axis of the outer working barrel is coincident with the axis of the inner working barrel, the outer working barrel comprises an upper joint 1, an upper outer sleeve 2 and a lower outer sleeve 7 which are sequentially connected in a sealing mode along the axis direction, and the outer through hole 13 is located in the side wall of the upper outer sleeve 2. The inner working barrel comprises a central tube 3 and a lower joint 10 which are sequentially and hermetically connected along the axis direction, one end of the central tube 3 is fixedly and hermetically connected with the upper joint 1, and one end of a lower outer sleeve 7 is fixedly and hermetically connected with the lower joint 10.

Specifically, the outer working barrel and the inner working barrel are both in an upright state, and the outer working barrel comprises an upper joint 1, an upper outer sleeve 2 and a lower outer sleeve 7 which are sequentially connected from top to bottom through threads. This interior working barrel contains from the top down through center tube 3 and the lower clutch 10 that the screw thread connects gradually, the upper end and the 1 threaded connection of top connection of center tube 3, the lower extreme and the 10 threaded connection of lower clutch of lower overcoat 7.

In the present embodiment, the first inner through hole 11 is located in the side wall of the center tube 3, the second inner through hole 12 is located in the side wall of the lower joint 10, the diameter of the first inner through hole 11 is equal to the diameter of the outer through hole 13, and the center line of the first inner through hole 11 coincides with the center line of the outer through hole 13. Through-hole 12 in first interior through-hole 11, the second and outer through-hole 13 all can with the annular cavity intercommunication, sliding sleeve 4 and dissolution delay ring 6 all are located in the annular cavity.

In this embodiment, the sliding sleeve 4 is in clearance fit or transition fit with the upper outer sleeve 2, the sliding sleeve 4 is in clearance fit or transition fit with the central tube 3, and the length of the sliding sleeve 4 is greater than the diameter of the first inner through hole 11, so that the sliding sleeve 4 can block the first inner through hole 11 and the second inner through hole 12.

In this embodiment, sliding sleeve 4 and last overcoat 2 sealing connection, if be equipped with the sealing washer between sliding sleeve 4 and the last overcoat 2, sliding

sleeve

4 and 3 sealing connection of center tube are equipped with the sealing washer between sliding sleeve 4 and the center tube 3. The sliding sleeve 4 is made of metal or alloy which can be dissolved in water, a shearing pin 5 is connected between the sliding sleeve 4 and the central tube 3, the outer peripheral surface and the inner peripheral surface of the sliding sleeve 4 are both provided with waterproof coatings, and the upper end surface and the lower end surface of the sliding sleeve 4 are both not provided with waterproof coatings.

In this embodiment, a first plug 301 is disposed in the first inner through hole 11, a second plug 302 is disposed in the outer through hole 13, and the first plug 301 and the second plug 302 are both water-insoluble paste, such as grease or animal oil. The first plug 301 and the second plug 302 can be used to protect the sliding sleeve 4 from sliding smoothly, and can prevent solid particulate matters such as well cement from entering the channel, as shown in fig. 2.

In this embodiment, the dissolution delay ring 6 is in clearance fit or transition fit with the lower outer sleeve 7, the dissolution delay ring 6 is in clearance fit or transition fit with the central tube 3, the dissolution delay ring 6 is in sealing connection with the lower outer sleeve 7, for example, a sealing ring is arranged between the dissolution delay ring 6 and the lower outer sleeve 7, the dissolution delay ring 6 is in sealing connection with the central tube 3, and a sealing ring is arranged between the dissolution delay ring 6 and the central tube 3.

In this embodiment, the inner end of the second inner through hole 12 is communicated with the inside of the lower joint 10, the outer end of the second inner through hole 12 is communicated with the annular cavity, the cylindrical compressing cap 8 is sleeved in the second inner through hole 12, and the compressing cap 8 is in threaded connection with the second inner through hole 12. The crushing disc 9 is located on the inner side of the second inner through hole 12, the pressing cap 8 is located on the outer side of the second inner through hole 12, the crushing disc 9 is abutted to the pressing cap 8, the crushing disc 9 is made of a metal sheet (such as an aluminum sheet), and the section of the crushing disc 9 is in a crescent shape protruding towards the pressing cap 8, as shown in fig. 1.

In use, the upper joint 1 and the lower joint 10 are connected with a production casing respectively through casing buckles. The dissolving sliding sleeve 4 is fixed on the outer side of the central tube 3 through a shearing pin 5. After the sliding sleeve 4 moves axially, the first inner through hole 11 and the second inner through hole 12 are communicated to form a fracturing fluid overflowing hole. The sliding sleeve 4 and the dissolution delay ring 6 are both made of the existing metal (such as magnesium) or alloy (such as aluminum alloy capable of dissolving in water) material capable of dissolving in water quickly. The annular cavity is divided into three mutually isolated hydraulic chambers by the sliding sleeve 4 and the dissolution delay ring 6, and the three chambers are sequentially named as an upper chamber, a middle chamber and a lower chamber from top to bottom in the figure 1. Wherein, the upper chamber is a vacuum chamber to reduce the sliding resistance of the upward movement of the sliding sleeve 4.

The contact surfaces between the central tube 3 and the upper joint 1, the dissolution sliding sleeve 4, the dissolution delay ring 6 and the lower joint 10 are all provided with sealing rings. And sealing rings are arranged on the contact surfaces between the upper outer sleeve 2 and the upper connector 1, and between the dissolving sliding sleeve 4 and the lower outer sleeve 7. And sealing rings are arranged on the contact surfaces between the lower outer sleeve 7 and the dissolution delay ring 6 and between the lower joint 10.

Further description of the dissolving time-delay toe sleeve is provided below.

When the completion of the oil and gas well enters a casing running stage, the upper joint 1 and the lower joint 10 of the dissolution type delay toe sliding sleeve are respectively connected with a technical casing and are run to a preset position in the well along with the casing. Then the oil well is cemented according to normal steps.

When the layered fracturing is needed, pressure is applied to the casing from the wellhead, and pressure fluid enters the central pipe 3 and the lower joint 10. When the pressure of the pressure fluid exceeds the designed breaking pressure of the rupture disc 9, the rupture disc 9 will be broken (i.e. ruptured) and the pressure fluid will pass through the rupture disc 9 into the lower chamber of the annular cavity. At this time, the pressure can be continuously increased to perform the pressure test operation of the casing. Meanwhile, the pressure liquid entering the lower chamber reacts with the dissolution delay ring 6, and the dissolution delay ring 6 starts to dissolve. After a time delay, the dissolution delay ring 6 is dissolved, and then the pressure fluid enters the middle chamber and pushes the sliding sleeve 4 to move upwards. When the sliding sleeve 4 moves upwards to a certain position, the first inner through hole 11 and the second inner through hole 12 are communicated and form a fracturing fluid overflowing hole, and then the fracturing operation of the first section (toe end) can be carried out. If the sliding sleeve 4 is blocked due to well cementing cement or other factors and can not slide normally, the sliding sleeve 4 is made of a water-soluble alloy material, and can be dissolved to expose a fracturing channel after standing for a period of time.

Because the water dissolution mode is adopted for time delay, the design breaking pressure of the crushing disc 9 arranged on the sliding sleeve at the end of the dissolution type time delay toe can be lower than the pressure test pressure of a well head and a sleeve, thereby ensuring the safety of the well head device and the sleeve. Examples are as follows: the pressure of the wellhead device and the casing pipe reaches 90MPa when pressure test is carried out, and the design breaking pressure of the crushing disc 9 can be set to 70 MPa. When the pressure test of the wellhead device is qualified at 90MPa during construction, and when the casing pressure rises to 70MPa, the crushing disc 9 is broken, and pressure liquid enters the dissolution starting delay ring 6. During the dissolution of the dissolution delay ring 6, the pressure of the casing can be continuously increased to 90MPa for pressure test. After the pressure test is finished, the dissolution delay ring 6 is also dissolved, and the fracturing channel is also opened at the same time. The first stage (toe) fracturing may continue at this point.

The dissolving type time-delay toe end sliding sleeve can be used for carrying out layered fracturing on an oil-gas well, pressure testing operation is carried out on a sleeve before a first section (toe end) fracturing channel is built by well head pressure testing, and the channel is opened in time to carry out first section fracturing after the pressure testing is finished. The method has important significance for reducing construction difficulty and fracturing cost of fracturing split layers.

The above description is only exemplary of the invention and should not be taken as limiting the scope of the invention, so that the invention is intended to cover all modifications and equivalents of the embodiments described herein. In addition, the technical features and the technical schemes, and the technical schemes can be freely combined and used.

Claims

1. A dissolving type time-delay toe end sliding sleeve is characterized by comprising an outer working barrel and an inner working barrel, wherein the outer working barrel is sleeved outside the inner working barrel, an annular cavity is formed between the outer working barrel and the inner working barrel, a sliding sleeve (4) and a dissolving time-delay ring (6) are sleeved between the outer working barrel and the inner working barrel, the sliding sleeve (4) and the dissolving time-delay ring (6) are arranged at intervals along the axial direction of the inner working barrel, a first inner through hole (11) and a second inner through hole (12) are arranged in the side wall of the inner working barrel, the first inner through hole (11) and the second inner through hole (12) are arranged at intervals along the axial direction of the inner working barrel, the dissolving time-delay ring (6) is positioned between the first inner through hole (11) and the second inner through hole (12), an outer through hole (13) is arranged in the side wall of the outer working barrel, and the first inner through hole (11) corresponds to the outer through hole (13), sliding sleeve (4) can block first interior through-hole (11) and outer through-hole (13), and sliding sleeve (4) can also be followed the axis direction of interior working barrel removes, and sealing connection has in through-hole (12) breaks dish (9) in the second, and the pressure liquid in this interior working barrel can break and break dish (9) and get into in the annular cavity, dissolve delay ring (6) and make by the metal or the alloy that can dissolve in water.

2. The dissolving type time-delay toe end sliding sleeve according to claim 1, wherein the outer working barrel comprises an upper connector (1), an upper outer sleeve (2) and a lower outer sleeve (7) which are hermetically connected in sequence along the axial direction, and the outer through hole (13) is positioned in the side wall of the upper outer sleeve (2).

3. The dissolving type time-delay toe end sliding sleeve according to claim 2, wherein the inner working barrel comprises a central tube (3) and a lower joint (10) which are sequentially connected in a sealing manner along the axial direction, one end of the central tube (3) is fixedly and hermetically connected with the upper joint (1), and one end of the lower outer sleeve (7) is fixedly and hermetically connected with the lower joint (10).

4. The dissolving time-delay toe sliding bush according to claim 3, wherein the first inner through hole (11) is located in the side wall of the central tube (3) and the second inner through hole (12) is located in the side wall of the lower joint (10), the diameter of the first inner through hole (11) being equal to the diameter of the outer through hole (13).

5. The dissolving delay toe end sliding sleeve according to claim 3, wherein the sliding sleeve (4) is in clearance fit or transition fit with the upper outer sleeve (2), the sliding sleeve (4) is in clearance fit or transition fit with the central tube (3), and the length of the sliding sleeve (4) is larger than the diameter of the first inner through hole (11).

6. The dissolution type delay toe end sliding sleeve according to claim 3, wherein the sliding sleeve (4) is hermetically connected with the upper outer sleeve (2), the sliding sleeve (4) is hermetically connected with the central tube (3), the sliding sleeve (4) is made of metal or alloy which can be dissolved in water, a shear pin (5) is connected between the sliding sleeve (4) and the central tube (3), and the outer circumferential surface and the inner circumferential surface of the sliding sleeve (4) are both waterproof coatings.

7. The dissolution type time-delay toe end sliding sleeve as claimed in claim 1, wherein a first plug (301) is arranged in the first inner through hole (11), a second plug (302) is arranged in the outer through hole (13), and the first plug (301) and the second plug (302) are both water-insoluble paste.

8. The dissolving type time-delay toe end sliding sleeve according to claim 3, wherein the dissolving time-delay ring (6) is in clearance fit or transition fit with the lower outer sleeve (7), the dissolving time-delay ring (6) is in clearance fit or transition fit with the central tube (3), the dissolving time-delay ring (6) is in sealing connection with the lower outer sleeve (7), and the dissolving time-delay ring (6) is in sealing connection with the central tube (3).

9. The dissolving type time-delay toe end sliding sleeve as claimed in claim 4, wherein one end of the second inner through hole (12) is communicated with the inside of the lower joint (10), the other end of the second inner through hole (12) is communicated with the annular cavity, and a cylindrical pressing cap (8) is fixedly sleeved in the second inner through hole (12).

10. The dissolving type time-delay toe end sliding sleeve according to claim 9, wherein the crushing disk (9) is positioned at the inner side of the second inner through hole (12), the pressing cap (8) is positioned at the outer side of the second inner through hole (12), the crushing disk (9) is abutted with the pressing cap (8), and the section of the crushing disk (9) is in a crescent shape protruding towards the pressing cap (8).