Toe-end sliding sleeve and its oil well string

Abstract

The present invention provides a toe-end sliding sleeve and an oil well string. The toe-end sliding sleeve includes: a body joint, which is provided with an axial through-hole, a pressure transmission hole, a rupture disk mounting hole and a rotary conduction valve assembly mounting hole. The pressure transmission hole is arranged in parallel and at an interval with the axial through-hole. The rupture disk mounting hole is arranged along the radial direction of the body joint and is respectively communicated with the pressure transmission hole and the axial through-hole. The rotary conduction valve assembly mounting hole is arranged in parallel and at an interval on one side of the rupture disk mounting hole; a sliding sleeve protective sleeve, which is fixedly sleeved outside the body joint, and an annulus is formed between the sliding sleeve protective sleeve and the body joint. The pressure transmission hole is communicated with the annulus; a sliding sleeve, which is arranged in the annulus through a shear pin; a rupture disk, which is arranged in the rupture disk mounting hole and can close the pressure transmission hole; a rotary conduction valve assembly, which is arranged in the rotary conduction valve assembly mounting hole, and the rotary conduction valve assembly can control the opening and closing of the pressure transmission hole. The present invention can achieve the purpose of automatically opening the sliding sleeve to establish a fracturing channel on the premise of meeting the pressure test pressure value.

Description

Technical Field

[0001] The present invention relates to the field of oil drilling and completion engineering, and particularly to a toe sleeve and an oil well string thereof. Background Art

[0002] With the continuous progress of drilling technology, the horizontal section of oil and gas wells is getting longer and longer. The first-stage fracturing operation mainly based on transmission perforation will face new challenges such as being unable to ensure that the perforating gun reaches the bottom of the well and high operation risks in ultra-long horizontal section wells and deep shale gas horizontal wells. However, the opening pressures of various existing cementing toe valves or toe sleeves are mostly unstable and lower than the rated pressure test value of the wellbore after casing cementing (the full-wellbore pressure test pressure of the casing is the highest pressure value for fracturing construction operations), that is, they cannot meet the requirements of full-wellbore pressure test before the first-stage fracturing of oil and gas wells. This not only affects the popularization and application of the tools, but also brings inconvenience to the later judgment of the integrity of the wellbore after cementing and construction operations. Summary of the Invention

[0003] The present invention provides a toe sleeve and an oil well string thereof, so as to achieve the purpose of a toe sleeve that can adapt to the full-wellbore pressure test for a certain time after casing cementing and then be opened by hydraulic pressure not higher than the pressure test value.

[0004] The technical solution adopted by the present invention to solve its technical problems is: a toe sleeve, comprising: a body joint, provided with an axial through hole, a pressure transmission hole, a rupture disk installation hole and a rotary conduction valve assembly installation hole, the pressure transmission hole is arranged in parallel and spaced from the axial through hole, the rupture disk installation hole is arranged along the radial direction of the body joint and is respectively communicated with the pressure transmission hole and the axial through hole, and the rotary conduction valve assembly installation hole is arranged in parallel and spaced on one side of the rupture disk installation hole; a sleeve protection sleeve, fixedly sleeved outside the body joint, and an annular space is formed between the sleeve protection sleeve and the body joint, and the pressure transmission hole is communicated with the annular space; a sleeve, arranged in the annular space through a shear pin; a rupture disk, arranged in the rupture disk installation hole and capable of closing the pressure transmission hole; a rotary conduction valve assembly, arranged in the rotary conduction valve assembly installation hole, and the rotary conduction valve assembly can control the opening and closing of the pressure transmission hole.

[0005] Further, the rotary conduction valve assembly includes: a rotary conduction valve, arranged along the radial direction of the body joint and located in the pressure transmission hole, a communication hole is opened at the valve body of the rotary conduction valve, and the communication hole can conduct the pressure transmission hole; a driving motor, arranged in the rotary conduction valve assembly installation hole and connected with the upper valve core of the rotary conduction valve, and the driving motor can drive the rotary conduction valve to rotate at the pressure transmission hole.

[0006] Further, a delay component mounting hole is also provided on the body joint. The delay component mounting hole is located between the rupture disk mounting hole and the rotary conduction valve component mounting hole, and the delay component mounting hole communicates with the rotary conduction valve component mounting hole. The toe-end sliding sleeve further includes a delay component, which is arranged in the delay component mounting hole and is electrically connected to the rotary conduction valve component.

[0007] Further, the delay component includes: a piston actuator, which is slidably arranged in the delay component mounting hole;

[0008] a battery timer, which is arranged in the delay component mounting hole and can be in contact conduction with the piston actuator, and the battery timer is connected to the drive motor and can supply power to the drive motor.

[0009] Further, the upper end of the rupture disk is fixed in the rupture disk mounting hole by a snap ring.

[0010] Further, the sliding sleeve protective cover and the body joint are connected by anti-loosening screws.

[0011] Further, a plurality of radial first fracturing holes are arranged at intervals on the sliding sleeve protective cover, and a plurality of radial second fracturing holes corresponding to the radial first fracturing holes one by one are arranged at intervals on the body joint. The toe-end sliding sleeve further includes a protective sheet, and a protective sheet is installed in each radial first fracturing hole and each radial second fracturing hole.

[0012] Further, a sealing component is arranged between the sliding sleeve protective cover and the body joint.

[0013] Further, a sealing component is arranged between the sliding sleeve and the sliding sleeve protective cover, and a sealing component is also arranged between the sliding sleeve and the body joint.

[0014] The present invention also provides an oil well string, which includes a toe-end sliding sleeve and a production tubing body. The toe-end sliding sleeve is the above-mentioned toe-end sliding sleeve, and the production tubing body is connected to the body joint.

[0015] The beneficial effect of the present invention is that the setting of the rupture disk can meet the requirement of conducting a full wellbore pressure test to the design pressure and the specified pressure test time before fracturing after cementing, and after the rupture disk is broken, the opening and closing of the pressure transmission hole can be controlled through the rotary conduction valve component, which can meet the purpose of automatically opening the sliding sleeve to establish a fracturing channel inside and outside the casing under the premise of not exceeding the pressure test value. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The specification drawings constituting a part of this application are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0017] Figure 1 is a schematic structural diagram of the sliding sleeve when it is not opened in the embodiment of the present invention;

[0018] Figure 2 is Figure 1 a partially enlarged view of;

[0019] Figure 3 is a schematic structural view of the sliding sleeve when it is opened in the embodiment of the present invention;

[0020] Figure 4 is Figure 3 a partially enlarged view of.

[0021] In the figure, reference numerals: 1, body joint; 2, snap ring; 3, rupture disc; 4, piston actuator; 5, battery timer; 6, drive motor; 7, rotary conduction valve; 8, pressure transmission hole; 9, locknut; 10, sliding sleeve protective sleeve; 11, sliding sleeve; 12, protection piece; 13, shear pin. Detailed implementation manners

[0022] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments may be combined with each other. The present invention will be described in detail below with reference to the drawings and in conjunction with the embodiments.

[0023] As Figures 1 to 4 shown, the embodiment of the present invention provides a toe-end sliding sleeve, which includes a body joint 1, a sliding sleeve protective sleeve 10, a sliding sleeve 11, a rupture disc 3 and a rotary conduction valve assembly. The body joint 1 is provided with an axial through hole, a pressure transmission hole 8, a rupture disc installation hole and a rotary conduction valve assembly installation hole. The pressure transmission hole 8 is arranged in parallel and at intervals with the axial through hole. The rupture disc installation hole is arranged along the radial direction of the body joint 1 and is respectively communicated with the pressure transmission hole 8 and the axial through hole. The rotary conduction valve assembly installation hole is arranged in parallel and at intervals on one side of the rupture disc installation hole. The sliding sleeve protective sleeve 10 is fixedly sleeved outside the body joint 1, and an annular space is formed between the sliding sleeve protective sleeve 10 and the body joint 1. The pressure transmission hole 8 is communicated with the annular space. The sliding sleeve 11 is arranged in the annular space through a shear pin 13. The rupture disc 3 is arranged in the rupture disc installation hole and can close the pressure transmission hole 8. The rotary conduction valve assembly is arranged in the rotary conduction valve assembly installation hole, and the rotary conduction valve assembly can control the opening and closing of the pressure transmission hole 8.

[0024] Setting the rupture disc 3 can meet the requirement of performing a full wellbore pressure test to the design pressure and the specified pressure test time before fracturing after cementing, and after the rupture disc 3 is broken, the opening and closing of the pressure transmission hole 8 can be controlled through the rotary conduction valve assembly, which can meet the purpose of automatically opening the sliding sleeve 11 to establish a fracturing channel inside and outside the casing on the premise of not exceeding the pressure test value.

[0025] It should be noted that the upper end of the rupture disc 3 is fixed in the rupture disc installation hole through a snap ring 2.

[0026] Specifically, the rotary conduction valve assembly includes a rotary conduction valve 7 and a drive motor 6. The rotary conduction valve 7 is arranged along the radial direction of the body joint 1 and is located in the pressure transmission hole 8. A communication hole is provided in the valve body of the rotary conduction valve 7, and the communication hole can conduct the pressure transmission hole 8. The drive motor 6 is fixedly arranged in the rotary conduction valve assembly mounting hole through the bottom card slot and is connected to the upper valve core of the rotary conduction valve 7. The drive motor 6 can drive the rotary conduction valve 7 to rotate at the pressure transmission hole 8.

[0027] The rotary conduction valve 7 in this embodiment has a ball valve-like structure, and a communication hole is provided in its radial direction. The drive shaft of the drive motor 6 is connected to the rotary conduction valve 7 and can drive the rotary conduction valve 7 to rotate by rotating the drive shaft, as Figure 2 and Figure 4 shown. When the rupture disc 3 is not broken, the communication hole is not connected to the pressure transmission hole 8, so that the pressure transmission holes 8 on both sides of the rotary conduction valve 7 are not conducted, thereby closing the pressure transmission hole 8. When the rupture disc 3 is broken, the drive motor 6 can drive the rotary conduction valve 7 to rotate 90°, so that the communication hole is connected to the pressure transmission hole 8, and then the axial through hole is connected to the annulus, so as to drive the sliding sleeve 11 to slide.

[0028] Preferably, a delay component mounting hole is further provided on the body joint 1. The delay component mounting hole is located between the rupture disc mounting hole and the rotary conduction valve assembly mounting hole, and the delay component mounting hole is communicated with the rotary conduction valve assembly mounting hole. The toe-end sliding sleeve further includes a delay component, which is arranged in the delay component mounting hole and is electrically connected to the rotary conduction valve assembly.

[0029] Setting the delay component can meet the requirements of conducting a full wellbore pressure test to the design pressure and the specified pressure test time before fracturing after cementing. After the pressure test is completed, on the premise that the pressure does not exceed the pressure test value, the sliding sleeve 11 automatically opens to establish a fracturing channel inside and outside the casing, and it is no longer necessary to transmit perforations through coiled tubing, so that the first-stage fracturing operation can be carried out, ultimately improving the completion operation efficiency and reducing the completion construction risk.

[0030] Specifically, the delay component includes a piston actuator 4 and a battery timer 5. The piston actuator 4 is slidably arranged in the delay component mounting hole. The battery timer 5 is arranged in the delay component mounting hole and can be in contact conduction with the piston actuator 4, and the battery timer 5 is connected to the drive motor 6 and can supply power to the drive motor 6.

[0031] Among them, the battery timer 5 in this embodiment is fixed in the delay component mounting hole by threads, and its lower end is hermetically arranged in the delay component mounting hole. The lower end of the battery timer 5 is connected to the piston actuator 4 through a spring, so as to ensure that the two do not come into contact under normal conditions. When the rupture disc 3 is broken, the pressure in the delay component mounting hole increases, thereby pushing the piston actuator 4 to move upward against the spring force, and then triggering the battery timer 5 to work.

[0032] The battery timer 5 supplies power to the drive motor 6 through a wire after a set delay time and makes the drive motor 6 operate. Under the action of the drive motor 6, the above-mentioned rotary conduction valve 7 rotates 90° so that the pressure transmission hole 8 is conducted.

[0033] As Figure 1 shown, a plurality of radial first fracturing holes are arranged at intervals on the slip protective sleeve 10, and a plurality of radial second fracturing holes corresponding to the radial first fracturing holes one by one are arranged at intervals on the body joint 1. The toe-end slip sleeve further includes a protective sheet 12, and the protective sheet 12 is installed in each radial first fracturing hole and each radial second fracturing hole. The protective sheet 12 in this embodiment can prevent cement consolidation, and its structure is the same as that of the protective sheet 12 in the prior art, so it will not be elaborated here.

[0034] It should be noted that a sealing assembly is provided between the slip protective sleeve 10 and the body joint 1 in this embodiment. A sealing assembly is provided between the slip 11 and the slip protective sleeve 10, and a sealing assembly is also provided between the slip 11 and the body joint 1. By providing the above-mentioned sealing assembly, stable sealing between various components can be ensured, and liquid leakage can be avoided.

[0035] Furthermore, in the embodiments of the present invention, a sealing assembly can also be provided between various components as needed to ensure the normal operation of each component.

[0036] Further preferably, the slip protective sleeve 10 and the body joint 1 are connected by a lock screw 9 to ensure the stable connection between the two.

[0037] The present invention also provides an oil well string, including a toe-end slip sleeve and a production tubing body. The toe-end slip sleeve is the above-mentioned toe-end slip sleeve, and the production tubing body is connected to the body joint 1.

[0038] Furthermore, the specific working process of the embodiment of the present invention is as follows:

[0039] Connect this embodiment to the cementing casing string according to the design requirements and lower it to the predetermined position to provide temporary plugging for the string and perform normal cementing operations (when performing cementing operations, the sum of the wellhead pump pressure and the hydrostatic pressure at the position of the delay-opening toe sleeve should be less than the fracture pressure value of the rupture disk 3); after the cementing operation, wait for the cement to completely solidify and reach the design strength before performing fracturing operations. During the fracturing operation, normally connect the fracturing wellhead to the fracturing truck and test the ground pipeline to the design value; after the wellhead pressure is relieved, open the wellhead valve to connect the fracturing truck to the wellbore through the ground pipeline, and open the fracturing truck to test the pressure to the design pressure value of the entire wellbore (the sum of the test pressure value and the hydrostatic pressure at the position of the delay-opening toe sleeve is greater than the fracture pressure value of the rupture disk 3). At this time, the rupture disk 3 in the delay-opening toe sleeve ruptures, and the fluid in the wellbore flows through the rupture disk 3 to the piston actuator 4 and the rotary conduction valve 7, and is blocked by the rotary conduction valve 7. At the same time, the fluid pressure pushes the piston actuator 4 to move radially outward along the tool and contacts the battery timer 5 to activate the battery timer 5 to start timing. When the battery timer 5 counts to the set value, it will automatically supply current to the drive motor 6. The drive motor 6 is turned on and drives the rotary conduction valve 7 to rotate 90 degrees to conduct the pressure transmission hole 8, and the fluid flows along the pressure transmission hole 8 to the sleeve 11 and pushes the sleeve 11 to move axially along the tool, so that the fracturing holes on the body joint 1 and the fracturing holes on the sleeve protection sleeve 10 are conducted, establishing a fracturing channel inside and outside the pipe (as Figure 2 shown), and perform normal first-stage fracturing operations.

[0040] From the above description, it can be seen that the above embodiments of the present invention achieve the following technical effects: The present invention is mainly used for the first-stage fracturing operation after cementing of oil and gas wells, especially horizontal wells, to provide full-wellbore pressure testing for oil and gas well fracturing and a fracturing channel between the inside of the casing and the formation during the first-stage fracturing operation, ultimately improving the completion operation efficiency and reducing the construction risk of the completion operation.

[0041] The above is only a specific embodiment of the present invention and cannot limit the scope of the invention. Therefore, the replacement of equivalent components or equivalent changes and modifications made according to the scope of protection of the present invention should still fall within the scope covered by this patent. In addition, the technical features in the present invention, the technical features and technical solutions, and the technical solutions can be freely combined and used with each other.

Claims

1. A toe-end sliding sleeve, characterized in that, Comprising: A body joint (1) provided with an axial through-hole, a pressure transmission hole (8), a rupture disk mounting hole, and a rotary conduction valve assembly mounting hole. The pressure transmission hole (8) is arranged in parallel and spaced from the axial through-hole. The rupture disk mounting hole is arranged along the radial direction of the body joint (1) and is respectively communicated with the pressure transmission hole (8) and the axial through-hole. The rotary conduction valve assembly mounting hole is arranged in parallel and spaced on one side of the rupture disk mounting hole; A sliding sleeve protective sleeve (10) fixedly sleeved outside the body joint (1), and an annular space is formed between the sliding sleeve protective sleeve (10) and the body joint (1). The pressure transmission hole (8) is communicated with the annular space; A sliding sleeve (11) arranged in the annular space through a shear pin (13); A rupture disk (3) arranged in the rupture disk mounting hole and capable of closing the pressure transmission hole (8); A rotary conduction valve assembly arranged in the rotary conduction valve assembly mounting hole, and the rotary conduction valve assembly can control the opening and closing of the pressure transmission hole (8); The rotary conduction valve assembly includes: A rotary conduction valve (7) arranged along the radial direction of the body joint (1) and located in the pressure transmission hole (8). A communication hole is provided in the valve body of the rotary conduction valve (7), and the communication hole can conduct the pressure transmission hole (8); A driving motor (6) arranged in the rotary conduction valve assembly mounting hole and connected to the upper valve core of the rotary conduction valve (7). The driving motor (6) can drive the rotary conduction valve (7) to rotate at the pressure transmission hole (8); A delay component mounting hole is also provided on the body joint (1). The delay component mounting hole is located between the rupture disk mounting hole and the rotary conduction valve assembly mounting hole, and the delay component mounting hole is communicated with the rotary conduction valve assembly mounting hole. The toe-end sliding sleeve further includes a delay component arranged in the delay component mounting hole and electrically connected to the rotary conduction valve assembly; The upper end of the rupture disk (3) is fixed in the rupture disk mounting hole by a snap ring (2).

2. The toe-end sliding sleeve according to claim 1, characterized in that, The delay component includes: A piston actuator (4) slidably arranged in the delay component mounting hole; A battery timer (5) arranged in the delay component mounting hole and capable of abutting and conducting with the piston actuator (4), and the battery timer (5) is connected to the driving motor (6) and can supply power to the driving motor (6).

3. The toe-end sliding sleeve according to claim 1, characterized in that, The sliding sleeve protective sleeve (10) and the body joint (1) are connected by a locknut (9).

4. The toe-end sliding sleeve according to claim 1, characterized in that, A plurality of radial first fracturing holes are arranged at intervals on the sliding sleeve protective sleeve (10). A plurality of radial second fracturing holes corresponding to the radial first fracturing holes one by one are arranged at intervals on the body joint (1). The toe-end sliding sleeve further includes a protective sheet (12), and a protective sheet (12) is installed in each of the radial first fracturing holes and each of the radial second fracturing holes.

5. The toe-end sliding sleeve according to claim 1, characterized in that, A sealing component is arranged between the sliding sleeve protective sleeve (10) and the body joint (1).

6. The toe-end sliding sleeve according to claim 1, characterized in that, A sealing component is arranged between the sliding sleeve (11) and the sliding sleeve protective sleeve (10), and a sealing component is also arranged between the sliding sleeve (11) and the body joint (1).

7. An oil well string, comprising a toe-end sliding sleeve and a production tubing body, characterized in that, The toe-end sliding sleeve is the toe-end sliding sleeve according to any one of claims 1 to 6, and the production tubing body is connected to the body joint (1).

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