A well cleanout, wellbore access, and pressure test integrated tool and method for toe slide sleeve wells

Abstract

The application provides a well washing, well passing and pressure testing integrated tool for a toe sliding sleeve well, which comprises a soluble well passing tool and a pressure testing seat, the pressure testing seat is a cylindrical structure, the soluble well passing tool is made of soluble material, and the soluble well passing tool is inserted into the pressure testing seat and is in sealed connection with the pressure testing seat. The pressure testing seat is preset above the toe sliding sleeve tool on the well completion pipe column, the soluble well passing tool is pumped to the pressure testing ball seat through the channel opened by the toe sliding sleeve before fracturing to complete well passing, and then the well mouth is pressurized to perform pre-fracturing pressure testing on the well mouth and the well bore. The tool and the method of the application eliminate the use of coiled tubing for well passing and well washing before fracturing of the toe sliding sleeve well, completely eliminate coiled tubing operation, and can perform integrated pressure testing without a matched pressure testing ball seat, thereby simplifying the process, reducing the organization difficulty of the field equipment, effectively improving the operation efficiency, reducing the well control risk, reducing the equipment and liquid consumption, and reducing the cost.

Description

Technical Field

[0001] This invention belongs to the field of oil and gas field fracturing technology, and specifically relates to an integrated tool and method for well cleaning, well ventilation and pressure testing of toe-end sliding sleeve wells without washing. Background Technology

[0002] In the casing-jacking bridge plug fracturing process for oil and gas wells, the conventional initial stage involves running coiled tubing (or tubing) with tools to flush the well and perform initial cable perforation to provide a pumping channel for the current fracturing stage and subsequent fracturing operations. Subsequent stages involve running bridge plug-type tools for modification. Currently, using a sliding sleeve tool at the casing toe end for wellhead pressure testing of the initial perforation and fracturing only eliminates the initial perforation operation. The reduction in pre-fracturing procedures, required equipment, and fluids is limited, resulting in insignificant efficiency improvements and cost reductions. Furthermore, it introduces the new problem of integrated fracturing and pressure testing of the wellbore.

[0003] Therefore, there is a need to design an integrated tool or method for well cleaning, well ventilation, and pressure testing of toe-end sliding sleeve wells that eliminates the need for continuous tubing (oil tubing) string insertion for well ventilation, thus eliminating the need for continuous tubing (oil tubing) ventilation and cleaning before fracturing of toe-end sliding sleeve wells. This completely eliminates the need for continuous tubing (oil tubing) operations and provides integrated pressure testing functionality without the need for a pressure testing ball seat. This simplifies procedures, reduces the difficulty of organizing on-site equipment, effectively improves operational efficiency, reduces well control risks, reduces equipment and fluid consumption, and lowers costs. Summary of the Invention

[0004] To address the aforementioned problems, this invention provides an integrated tool and method for no-washing, well cleaning, and pressure testing of toe-end sliding sleeve wells, which can effectively improve operational efficiency, reduce well control risks, decrease equipment and fluid consumption, and lower costs. To achieve the above objectives, the following technical solution is adopted:

[0005] A no-washing, well-clearing, and pressure-testing integrated tool for toe-end sliding sleeve wells includes a soluble well-clearing tool and a pressure-testing seat. The pressure-testing seat has a cylindrical structure, and the soluble well-clearing tool is made of a soluble material. The soluble well-clearing tool is inserted into the pressure-testing seat and is sealed to the pressure-testing seat.

[0006] Preferably, one end of the soluble well-draining tool is provided with a sealing section, and the sealing section is provided with a first sealing surface; the inside of the pressure testing seat is provided with a second sealing surface that is adapted to the first sealing surface.

[0007] Preferably, the first sealing surface is a spherical surface, and the second sealing surface is an inclined surface or an arc surface adapted to the spherical surface.

[0008] Preferably, the sealing section is a first reduced diameter section, and the spherical surface terminates the first reduced diameter section.

[0009] Preferably, the test pressure seat is provided with a second reduced diameter section for locking the sealing section, and the second sealing surface is located above the second reduced diameter section.

[0010] Preferably, the sealing section is a first reduced diameter section, the first sealing surface is the side surface of the first reduced diameter section, and the test pressure seat is provided with a second reduced diameter section for locking the sealing section, the second sealing surface being the side surface of the second reduced diameter section.

[0011] Preferably, the first sealing surface or the second sealing surface is provided with a plurality of sealing grooves in the circumferential direction, and a sealing ring is provided in the sealing groove.

[0012] Preferably, the diameter of the maximum outer diameter section of the soluble wellbore tool is 6-8 mm smaller than the inner diameter of the casing being lowered into the well, and the length of the maximum outer diameter is ≥800 mm.

[0013] Preferably, the test pressure seat has threaded connections at both ends.

[0014] A method for integrated well cleaning, well ventilation, and pressure testing without washing in toe-end sliding sleeve wells, based on the aforementioned tool, includes the following steps:

[0015] The pre-positioned pressure test seat is placed above the toe end sliding sleeve tool on the completion tubing string and lowered in with the tubing string;

[0016] Cementing was performed using a dissolving agent, followed by cementing pressure testing and displacement.

[0017] Install fracturing wellheads;

[0018] Pressurize the wellhead and open the toe-end sliding tool;

[0019] The soluble well-clearing tool is pumped into the test pressure seat at a certain point above the toe sleeve to complete the well clearance;

[0020] Wellhead pressurization involves conducting a pre-fracturing pressure test on the fracturing wellhead and wellbore.

[0021] Once the soluble well-drilling tool has dissolved, subsequent operations can be completed.

[0022] Preferably, the dissolving fluid is selected from fracturing pre-fluid, displacement fluid or perforation fluid.

[0023] The present invention has the following beneficial effects: Before fracturing, the present invention uses the channel opened by the toe-end sliding sleeve to pump the soluble well-running tool to the test pressure ball seat to complete the well-running. Then, the wellhead is pressurized to conduct a pre-fracturing pressure test on the wellhead and wellbore. The tool and method of the present invention eliminate the need for continuous tubing (oil tubing) to circulate and flush the well before fracturing the toe-end sliding sleeve well, completely eliminating the continuous tubing (oil tubing) operation. Moreover, it can perform integrated pressure testing without the need for a matching test pressure ball seat, simplifying the process, reducing the difficulty of organizing on-site equipment, effectively improving the operation efficiency, reducing well control risks, reducing equipment and fluid consumption, and reducing costs.

[0024] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This invention illustrates a schematic diagram of the integrated tool structure for a toe-end sliding sleeve well that requires no cleaning and includes well cleaning and pressure testing.

[0027] Figure 2 A schematic diagram of the soluble well-drainage tool structure of Embodiment 2 of the present invention is shown;

[0028] Figure 3 A schematic diagram of the soluble well-drainage tool structure of Embodiment 3 of the present invention is shown;

[0029] Figure 4 A schematic diagram of the test pressure seat structure of the present invention is shown.

[0030] In the figure: 1. Soluble well tool; 11. Solid section; 12. Maximum outer diameter section; 13. First reduced diameter section; 14. First sealing surface; 15. Spherical surface; 16. Sealing groove; 2. Test pressure seat; 21. Second reduced diameter section; 22. Second sealing surface; 23. Inclined surface. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] Example 1

[0033] A tool for integrated well cleaning, well ventilation, and pressure testing for toe-end sliding sleeve wells, such as... Figure 1As shown, the device includes a soluble wellbore cleaning tool 1 and a pressure testing seat 2. The soluble wellbore cleaning tool 1 is made of a soluble material (such as an aluminum-based alloy or a magnesium-based alloy) and has a solid section 11 longitudinally arranged inside. The diameter of the maximum outer diameter section 12 of the soluble wellbore cleaning tool 1 is 6-8 mm smaller than the inner diameter of the casing being lowered into the well. The length of the maximum outer diameter is ≥800 mm. The lower end of the soluble wellbore cleaning tool 1 has a first diameter reduction section 13 (the diameter of one end near the soluble wellbore cleaning tool 1 is larger than the diameter of the other end), and the first diameter reduction section 13 has a first sealing surface 14. The pressure testing seat 2 has a cylindrical structure, such as... Figure 4 As shown, the pressure test seat 2 has threaded connections at both ends. Inside the pressure test seat 2 is a second reduced-diameter section 21 for securing the first reduced-diameter section 13. The second sealing surface 22 is adapted to the first sealing surface 14. The soluble wellbore cleaning tool 1 is inserted into the pressure test seat 2 and sealed to it. Specifically, after the soluble wellbore cleaning tool 1 is inserted into the oil and gas well tubing, it sits in the pressure test seat 2. The first sealing surface 14 seals with the second sealing surface 22, and the soluble wellbore cleaning tool 1 isolates the oil and gas well tubing into upper and lower cavities at the pressure test seat 2.

[0034] Example 2

[0035] Based on Example 1, such as Figure 2 , Figure 4 As shown, the first sealing surface 14 of the soluble well-drainage tool 1 is a spherical surface 15, which terminates the first diameter reduction section 13. The second sealing surface 22 is an inclined surface 23 (or an arc surface) adapted to the spherical surface 15, located at the upper end of the second diameter reduction section 21. The spherical surface 15 and the inclined surface 23 (or arc surface) cooperate to form an elastic-plastic deformation, achieving a tight seal between the sealing surfaces.

[0036] Example 3

[0037] Based on Example 1, such as Figure 3 , Figure 4 As shown, the sealing section of the soluble well-draining tool 1 is a first reduced-diameter section, and the side of the first reduced-diameter section is a first sealing surface 14. The test pressure seat is provided with a second reduced-diameter section for locking the sealing section, and the second sealing surface 22 is the side of the second reduced-diameter section. The first sealing surface 14 or the second sealing surface 22 is provided with a plurality of sealing grooves 16 circumferentially, and sealing rings are provided in the sealing grooves 16. The second sealing surface 22 of the test pressure seat 2 is configured to cooperate with the first sealing surface 14.

[0038] The working principle of the integrated wellbore cleaning and pressure testing tool for toe-end sliding sleeve wells is as follows: A pre-placed pressure testing seat 2 is positioned above the toe-end sliding sleeve tool on the completion string and lowered with the string; pre-fracturing fluid, displacement fluid, or perforation fluid is used for cementing and pressure testing; the fracturing wellhead is installed; the toe-end sliding sleeve tool is opened by pressurizing the wellhead; a soluble wellbore cleaning tool 1 is pumped into the pressure testing seat 2 above the toe-end sliding sleeve to complete wellbore cleaning; the wellhead is pressurized to perform pre-fracturing pressure testing on the fracturing wellhead and wellbore; after the soluble wellbore cleaning tool 1 dissolves, subsequent operations are completed. This invention eliminates the need for continuous tubing (oil tubing) cleaning and venting before fracturing toe-end sliding sleeve wells, completely eliminating continuous tubing (oil tubing) operations. Furthermore, it allows for integrated pressure testing without the need for a matching pressure testing ball seat, simplifying procedures, reducing the difficulty of organizing on-site equipment, effectively improving operational efficiency, reducing well control risks, reducing equipment and fluid consumption, and lowering costs.

[0039] Example 4

[0040] A method for integrated well cleaning, well ventilation, and pressure testing of toe-end sliding sleeve wells without washing, based on the aforementioned integrated well cleaning, well ventilation, and pressure testing tool for toe-end sliding sleeve wells, includes the following steps:

[0041] Step 1: Place the test pressure seat 2 at a certain point above the toe end sliding sleeve tool on the completion tubing string, and lower it in with the tubing string;

[0042] Step 2: Use fracturing pre-flush fluid, displacement fluid or perforation fluid for cementing and complete cementing pressure testing;

[0043] Step 3: Install the fracturing wellhead;

[0044] Step 4: Pressurize the wellhead to open the toe-end sliding sleeve tool;

[0045] Step 5: Pump the soluble well-clearing tool 1 into the test pressure seat 2 above the toe end of the sliding sleeve to complete the well clearance;

[0046] Step 6: Pressurize the wellhead and perform a pre-fracturing pressure test on the fracturing wellhead and wellbore;

[0047] Step 7: Once the soluble well-drainage tool 1 has dissolved, the subsequent operations are complete.

[0048] For example, in this embodiment, a no-wash well and well pressure test were performed in a fracturing and modified tubing string with an outer diameter of 114.3 mm according to the above steps and methods. The specific parameters are as follows:

[0049] The pressure test seat 2 is connected between the pipe fittings and is a cylindrical body with open ends. The inner diameter has sleeves at both ends and contains a second reduced diameter section 21 and a second sealing surface 22. After the soluble well-clearing tool 1 is inserted into the oil and gas well tubing, it falls to the reduced diameter section of the pressure test seat 2 and sits there. The first sealing surface 14 and the second sealing surface 22 seal each other. The soluble well-clearing tool 1 isolates the tubing into upper and lower cavities at the pressure test seat 2.

[0050] In summary, the technical solution of this invention uses pre-fracturing fluid, displacement fluid, or perforation fluid for cementing and displacement. Before fracturing, a soluble well-running tool is pumped to the test ball seat through the channel opened by the toe-end sliding sleeve to complete well-running. Then, the wellhead is pressurized to perform pre-fracturing pressure testing on the wellhead and wellbore. The tool and method of this invention eliminate the need for continuous tubing (oil tubing) for well-running and flushing before fracturing of toe-end sliding sleeve wells, completely eliminating continuous tubing (oil tubing) operations. Furthermore, integrated pressure testing can be performed without the need for a matching test ball seat, simplifying the process, reducing the difficulty of organizing on-site equipment, effectively improving operational efficiency, reducing well control risks, reducing equipment and fluid consumption, and lowering costs.

[0051] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for integrated well cleaning, well ventilation, and pressure testing without washing in toe-end sliding sleeve wells, characterized in that, This invention relates to an integrated tool for wellbore cleaning, wellbore testing, and pressure testing based on a toe-end sliding sleeve well. The tool includes a soluble wellbore cleaning tool and a pressure testing seat. The pressure testing seat has a cylindrical structure. The soluble wellbore cleaning tool is made of a soluble material and is inserted into and sealed to the pressure testing seat. One end of the soluble wellbore cleaning tool has a sealing section with a first sealing surface. The pressure testing seat has a second sealing surface adapted to the first sealing surface. The first sealing surface is spherical, and the second sealing surface is inclined or conforms to the first sealing surface. The spherical surface is adapted to the arc surface; the sealing section is a first reduced diameter section, and the spherical surface terminates the first reduced diameter section; the pressure test seat is provided with a second reduced diameter section for securing the sealing section, and the second sealing surface is located above the second reduced diameter section; the sealing section is the first reduced diameter section, the first sealing surface is the side surface of the first reduced diameter section, the pressure test seat is provided with a second reduced diameter section for securing the sealing section, and the second sealing surface is the side surface of the second reduced diameter section; the diameter of the maximum outer diameter section of the soluble wellbore tool is smaller than the inner diameter of the casing being lowered into the well by 6 mm. 8mm, wherein the length of the maximum outer diameter is ≥800mm; The method includes the following steps: The pre-positioned test pressure seat is placed above the toe end sliding sleeve tool on the completion string and lowered in with the string; cementing is carried out using dissolving fluid and cementing test pressure replacement is completed. Install fracturing wellheads; Pressurize the wellhead and open the toe-end sliding tool; The soluble well-clearing tool is pumped into the test pressure seat at a certain point above the toe sleeve to complete the well clearance; Wellhead pressurization involves conducting a pre-fracturing pressure test on the fracturing wellhead and wellbore. Once the soluble well-drilling tool has dissolved, subsequent operations can be completed.

2. The integrated method for no-washing well cleaning, well ventilation, and pressure testing of a toe-end sliding sleeve well according to claim 1, characterized in that, The first or second sealing surface is provided with a plurality of sealing grooves in the circumferential direction, and a sealing ring is provided in the sealing groove.

3. The integrated method for no-washing well cleaning, well ventilation, and pressure testing of a toe-end sliding sleeve well according to claim 1, characterized in that, The test pressure seat has threaded connections at both ends.

4. The integrated method for no-washing well cleaning, well ventilation, and pressure testing of a toe-end sliding sleeve well according to claim 1, characterized in that, The dissolving fluid is selected from fracturing pre-fluid, displacement fluid or perforation fluid.

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