Composite expansion pipe and shaft repairing and reconstructing method based on composite expansion pipe

Abstract

The invention provides a composite expansion pipe and a shaft repairing and reconstructing method based on the composite expansion pipe, and relates to the technical field of oil and gas well workover, the composite expansion pipe comprises a pipe body, a first expansion cone and a second expansion cone, and the pipe body comprises a first emission section, a first expansion section, a diameter expansion section, a second emission section and a second expansion section which are sequentially arranged in the axial direction; the first expansion cone is arranged in the first emission section, the outer diameter of the first expansion cone is larger than the inner diameter of the first expansion section, and the first expansion cone can move into the first expansion section to enable the first expansion section to expand outwards; the second expansion cone is arranged in the second emission section, the outer diameter of the second expansion cone is larger than the inner diameter of the second expansion section, and the second expansion cone can move into the second expansion section and enables the second expansion section to expand outwards; the outer diameter of the second expansion cone is larger than that of the first expansion cone. According to the composite expansion pipe and the shaft repairing and reconstructing method based on the composite expansion pipe, the success rate and efficiency of repairing construction of the composite sleeve can be effectively improved.

Description

Technical Field

[0001] This invention relates to the field of oil and gas well workover technology, and in particular to a composite expansion pipe and a wellbore repair and reconstruction method based on the composite expansion pipe. Background Technology

[0002] In oil and gas well production, casing damage and water production from the producing formation are common problems in older wells that have entered the mid-to-late stages of production. Casing damage manifests in various forms, mainly including casing breakage, deformation, and corrosion. Currently, a large number of wells with casing damage exist in various oilfields, severely affecting normal oil and gas well production and causing huge economic losses. Effective technical means are needed to repair or seal the damaged well sections to restore production.

[0003] Casing damage repair technologies mainly include expansion tube casing damage repair, packer isolation, casing replacement, small casing cementing, chemical plugging, and cement injection plugging. With the diversification of wellbore structure designs, the number of wells completed using composite production casing is gradually increasing. However, because composite production casing has a variable diameter structure, conventional methods cannot repair casing damage occurring at the composite diameter variation point.

[0004] In view of this, based on years of experience in production and design in this and related fields, the inventor has designed a composite expansion tube and a wellbore repair and reconstruction method based on the composite expansion tube through repeated experiments, in order to solve the problems existing in the prior art. Summary of the Invention

[0005] The purpose of this invention is to provide a composite expansion tube and a wellbore repair and reconstruction method based on the composite expansion tube, which can effectively improve the repair construction efficiency and success rate of composite casing.

[0006] To achieve the above objectives, the present invention proposes a composite expansion tube, wherein the composite expansion tube comprises:

[0007] The tube body includes, in an axial sequence, a first launching section, a first expansion section, an enlarged diameter section, a second launching section, and a second expansion section;

[0008] A first expansion cone is disposed within the first emission section. The outer diameter of the first expansion cone is larger than the inner diameter of the first expansion section and can move into the first expansion section to cause the first expansion section to expand outward.

[0009] A second expansion cone is disposed within the second launching section. The outer diameter of the second expansion cone is larger than the inner diameter of the second expansion section, and the second expansion cone can move into the second expansion section and cause the second expansion section to expand outward.

[0010] The outer diameter of the second expansion cone is larger than the outer diameter of the first expansion cone.

[0011] This invention also proposes a wellbore repair and reconstruction method based on the composite expansion tube described above, wherein the wellbore repair and reconstruction method includes:

[0012] Calculate the size parameters of the composite expansion pipe based on the size parameters of the downhole composite casing and the location of the casing damage point, and then manufacture the composite expansion pipe.

[0013] The composite expansion pipe is placed downhole, with the second expansion section and the first expansion section positioned above and below the casing damage point, respectively.

[0014] The first expansion cone is pushed to move to the first expansion section, causing the first expansion section to expand outward and fit tightly against the inner wall of the composite sleeve.

[0015] The second expansion cone is pushed to move to the second expansion section and the second expansion section expands outward and fits tightly against the inner wall of the composite sleeve.

[0016] Compared with the prior art, the present invention has the following features and advantages:

[0017] The composite expansion pipe proposed in this invention adopts a two-stage expansion structure, which can complete the expansion of two specifications of composite expansion sections in one drilling run. Based on this composite expansion pipe, it is possible to achieve one-time repair of damaged variable diameter composite production casing, with high construction efficiency and good repair effect. After repair, the inner diameter of the wellbore only loses the wall thickness of two expansion sections, and the inner diameter is large, which is more conducive to subsequent production operations. Attached Figure Description

[0018] The accompanying drawings described herein are for illustrative purposes only and are not intended to limit the scope of the invention in any way. Furthermore, the shapes and proportions of the components in the drawings are merely illustrative to aid in understanding the invention and do not specifically limit the shapes and proportions of the components. Those skilled in the art, guided by the teachings of this invention, can select various possible shapes and proportions to implement the invention according to specific circumstances.

[0019] Figure 1 This is a schematic diagram of the composite production casing damage in this invention;

[0020] Figure 2 This is a structural diagram of the composite expansion tube column in this invention;

[0021] Figure 3 This is a schematic diagram of the expansion of the composite expansion tube in this invention;

[0022] Figure 4 This is a schematic diagram of the composite production sleeve after repair in this invention.

[0023] Explanation of reference numerals in the attached figures

[0024] 100. Composite expansion tube; 10. Tube body;

[0025] 11. First launch stage; 12. First expansion stage;

[0026] 13. Expanded diameter section; 14. Second launch section;

[0027] 15. Second expansion section; 20. First expansion cone;

[0028] 30. Second expansion cone; 40. First suspension sealing structure;

[0029] 50. Second suspension sealing structure; 200. Composite production sleeve;

[0030] 210. Large diameter section; 220. Reduced diameter section;

[0031] 230, small diameter section; 300, point of loss;

[0032] 400. Drilling tools are inserted; 500. The repaired wellbore. Detailed Implementation

[0033] The details of the present invention can be more clearly understood by referring to the accompanying drawings and the description of specific embodiments. However, the specific embodiments of the present invention described herein are for illustrative purposes only and should not be construed as limiting the invention in any way. Under the teachings of this invention, those skilled in the art can conceive of any possible modifications based on the invention, and these should all be considered to fall within the scope of the invention.

[0034] like Figure 1 As shown, the present invention proposes a composite expansion tube 100, which includes a tube body 10, a first expansion cone 20, and a second expansion cone 30. The tube body 10 includes a first emitting section 11, a first expansion section 12, an enlarged diameter section 13, a second emitting section 14, and a second expansion section 15 arranged sequentially along the axial direction. The first expansion cone 20 is disposed within the first emitting section 11, and the outer diameter of the first expansion cone 20 is larger than the inner diameter of the first expansion section 12 and can move into the first expansion section 12 to cause the first expansion section 12 to expand outward. The second expansion cone 30 is disposed within the second emitting section 14, and the outer diameter of the second expansion cone 30 is larger than the inner diameter of the second expansion section 15 and can move into the second expansion section 15 to cause the second expansion section 15 to expand outward. The outer diameter of the second expansion cone 30 is larger than the outer diameter of the first expansion cone 20.

[0035] The composite expansion pipe 100 proposed in this invention employs a two-stage expansion cone for double expansion, with the two expansion cones having different outer diameters. This creates two expansion sections with different pipe diameters, enabling the sealing and repair of wellbores with different pipe diameters. It is particularly suitable for composite production casings with variable diameter structures. In use, the first expansion cone 20 expands the first expansion section 12 (small diameter expansion section), and the second expansion cone 30 expands the second expansion section 15 (large diameter expansion section), sequentially completing the patching and repair of two specifications of casing, reconstructing the integrity of the composite casing wellbore, and enabling damaged wells to resume production.

[0036] The composite expansion pipe 100 proposed in this invention adopts a two-stage expansion structure, which can complete the expansion of two specifications of composite expansion sections in one drilling run. Based on this composite expansion pipe 100, it is possible to achieve one-time repair of damaged variable diameter composite production casing 200, with high construction efficiency and good repair effect. After repair, the inner diameter of the wellbore only loses the wall thickness of two expansion sections, and the inner diameter is large, which is more conducive to subsequent production operations.

[0037] This invention also proposes a wellbore repair and reconstruction method based on a composite expansion tube 100, which includes:

[0038] Calculate the dimensions of the composite expansion tube 100 based on the dimensions of the downhole composite production casing 200 and the location of the casing damage point 300, and then fabricate the composite expansion tube 100.

[0039] The composite expansion pipe 100 is lowered into the well, with the second expansion section 15 and the first expansion section 12 positioned above and below the casing damage point 300, respectively.

[0040] The first expansion cone 20 is moved to the first expansion section 12, causing the first expansion section 12 to expand outward and fit tightly against the inner wall of the composite production sleeve 200.

[0041] The second expansion cone 30 is pushed to move to the second expansion section 15 and the second expansion section 15 expands outward and adheres tightly to the inner wall of the composite production sleeve 200.

[0042] The wellbore repair and reconstruction method proposed in this invention addresses the casing damage problem of the composite production casing 200. Based on the dimensions of the two types of casing at the diameter change point of the composite production casing 200 and the location of the casing damage point, the size of the composite expansion pipe 100 is determined and the composite expansion pipe 100 is manufactured. This makes the customized composite expansion pipe 100 more suitable for the size of the composite production casing 200, especially for repairing the casing damage point at the diameter change point of the composite production casing 200. By using the customized composite expansion pipe 100 to repair the composite production casing 200, the damaged well section of two casing specifications can be repaired at one time. Moreover, the repaired wellbore has a large inner diameter and high annular pressure bearing capacity, which facilitates subsequent production operations.

[0043] In an optional embodiment of the present invention, the composite production sleeve 200 includes a large-diameter section 210, a reduced-diameter section 220 and a small-diameter section 230 arranged sequentially from top to bottom, with a first expansion section 12 aligned and tightly attached to the inner wall of the small-diameter section 230, and a second expansion section 15 aligned and tightly attached to the inner wall of the large-diameter section 210.

[0044] In an optional embodiment of the present invention, a first suspension sealing structure 40 is provided over the first expansion section 12, and a second suspension sealing structure 50 is provided over the second expansion section 15. The first suspension sealing structure 40 can seal the annulus between the first expansion section 12 and the composite production casing 200, and the second suspension sealing structure 50 can seal the annulus between the second expansion section 15 and the composite production casing 200, thereby achieving the fit between the first expansion section 12, the second expansion section 15 and the composite production casing 200, and completing the repair of the damaged well section.

[0045] In an optional embodiment of the present invention, the second expansion cone 30 and the first expansion cone 20 are fed into the composite production casing 200 by the feed drill 400, and the first expansion cone 20 and the second expansion cone 30 are pushed by the feed drill 400.

[0046] In an alternative example, the first expansion cone 20 and the second expansion cone 30 are moved by hydraulic pressure. Specifically, the tube body 10 is closed at one end of the first launching section 11 and open at the other end. The first expansion cone 20 and the second expansion cone 30 each have an installation cavity that extends through the tube body 10 along its axial direction. The first expansion cone 20 is in a sealing sliding fit with the inner wall of the first launching section 11, and the second expansion cone 30 is in a sealing sliding fit with the inner wall of the second launching section 14.

[0047] Using the above structure, a feed drill bit 400 with an axially penetrating cavity is employed. The feed drill bit 400 sequentially penetrates the mounting cavity of the second expansion cone 30 and the mounting cavity of the first expansion cone 20. Pressure is applied through the penetrating cavity of the feed drill bit 400 and the injection channel of the first expansion cone 20. Fluid flows through the penetrating cavity of the feed drill bit 400 into the first launching section 11, forming a hydraulic cavity within the first launching section 11. Under the action of hydraulic pressure, the first expansion cone 20 is driven to move, thereby causing the first expansion section 12 to expand. The first suspension sealing structure 40 outside the first expansion section 12 is compressed, causing the first expansion cone 20 to expand. The first expansion section 12 is tightly attached to the inner wall of the small diameter section 230, forming a reliable seal. After the first expansion section 12 has fully expanded, the first expansion cone 20 continues to move to the second launching section 14. Then, the first expansion cone 20 and the second expansion cone 30 are connected to form a composite expansion cone. Under the continued action of hydraulic pressure, the composite expansion cone moves upward, causing the second expansion section 15 to expand. The second suspension sealing structure 50 outside the second expansion section 15 is compressed, causing the second expansion section 15 to be tightly attached to the inner wall of the large diameter section 210, forming a reliable seal, thus completing the expansion process of the composite expansion tube.

[0048] Furthermore, the first expansion cone 20 has a first mating structure at the end facing the second expansion cone 30, and the second expansion cone 30 has a second mating structure at the end facing the first expansion cone 20. Through the alignment and cooperation of the first and second mating structures, the first expansion cone 20 and the second expansion cone 30 form a composite expansion cone. In an optional example, the first and second mating structures can be aligned bosses, grooves, or other mating structures.

[0049] In an optional embodiment of the present invention, the inner diameter of the second expansion section 15 is larger than the inner diameter of the first expansion section 12. That is, the first expansion section 12 with a smaller inner diameter corresponds to the small-diameter section 230 of the composite production casing 200, and the second expansion section 15 with a larger inner diameter corresponds to the large-diameter section 210 of the composite production casing 200. The new wellbore formed by the composite expansion pipe 100 after repair also has a structure with a large-diameter section at the top and a small-diameter section at the bottom, ensuring that the repaired wellbore still has good throughput.

[0050] In an optional embodiment of the present invention, the inner diameter d of the large-diameter section 210 of the composite production sleeve 200 is... c1 The inner diameter d of the minor diameter segment 230 c2 The dimensions of each part of the composite expansion tube 100 are calculated based on the location of the damage point.

[0051] In this embodiment, there can be one, two or more damage points, located between the large diameter section 210 and the small diameter section 230.

[0052] In an optional example of this embodiment, the dimensional parameters of the composite expansion tube 100 include the outer diameter, wall thickness, and expanded inner diameter of the first expansion section 12, and the outer diameter, wall thickness, and expanded inner diameter of the second expansion section 15.

[0053] In one alternative example, the outer diameter of the first expansion section 12 is about 10-15 mm smaller than the inner diameter of the small diameter section 230, the outer diameter of the second expansion section 15 is about 10-15 mm smaller than the inner diameter of the large diameter section 210, and the wellbore size after the composite expansion pipe 100 is repaired is 15-25 mm smaller than the inner diameter of the original composite production casing.

[0054] In one optional example, the length of the first expansion section 12, the length of the second expansion section 15, and the overall length of the pipe body 10 are determined based on the location and length of each damage point on the composite production casing 200.

[0055] In an optional embodiment of the present invention, the wellbore repair and reconstruction method further includes:

[0056] Before the composite expansion pipe 100 is lowered into the well, well conditions are verified to ensure that the composite expansion pipe 100 can be safely lowered and expanded.

[0057] Specifically, a two-stage simulated wellbore tool should be used for wellbore verification. The outer diameter of the two-stage simulated wellbore gauge should be consistent with the maximum outer diameter of the composite expansion tube 100. An annular suspension sealing structure should be installed outside the wellbore gauge. Through simulated wellbore verification, it can be confirmed whether the wellbore conditions meet the requirements for the insertion and expansion of the composite expansion tube 100. Simultaneously, the damage to the suspension sealing structure should be observed after the simulated wellbore tool is retrieved to determine whether the wellbore conditions meet the suspension sealing requirements. Using a two-stage simulated wellbore tool can better simulate the insertion state of the composite expansion tube 100, better verify whether the wellbore conditions meet the requirements for repairing the composite expansion tube 100, and significantly reduce construction risks.

[0058] In one optional embodiment of the present invention, the composite expansion pipe 100 is sent downhole using a drive-in drill string. The drive-in drill string is connected to the first expansion cone 20 in the first launching section 11 of the composite expansion pipe 100, and the composite expansion pipe 100 is sent to the designed well depth. Based on the size of the composite expansion pipe 100 and the wellbore conditions, a suitable drive-in drill string is selected through downhole calculation and analysis, taking into account the strength of the drill string, to ensure that the composite expansion pipe 100 is successfully lowered into place.

[0059] In an optional embodiment of the present invention, the wellbore repair and reconstruction method further includes:

[0060] The bottom of the pipe body 10 is milled using a milling tool until the pipe body 10 is in a state of vertical continuity, in order to restore the integrity of the wellbore.

[0061] Now, in conjunction with an embodiment, Figures 1 to 4 The following diagram illustrates the specific implementation process of the composite expansion tube proposed in this invention and the wellbore repair and reconstruction method based on the composite expansion tube.

[0062] First, the composite expansion tube and tooling were designed.

[0063] like Figure 1 As shown, a well casing has a small-diameter section 230 and a large-diameter section 210 as a composite production casing. There are two damage points 300 (i.e., damaged sections) within this casing. To restore well integrity and ensure normal production, a composite expansion pipe 100 is used for repair. Based on the inner diameter d of the small-diameter section 230... c1 and the inner diameter d of the large diameter section 210 c2 The outer diameter, wall thickness, and inner diameter after expansion of the first expansion section 12 and the second expansion section 15 in the composite expansion tube 11 are determined (the dimensions are the same as those of the first expansion cone 20 and the second expansion cone 30, respectively). The outer diameter of the composite expansion tube 100 is about 10 to 15 mm smaller than the inner diameter of the composite production casing 200 at the corresponding position. After the composite expansion tube 100 is repaired, the inner diameter of the wellbore is about 15 to 25 mm smaller than the inner diameter of the original casing.

[0064] Next, wellbore condition verification will be conducted.

[0065] A two-stage simulated wellbore tool was used, with the tool's outer diameter matching that of the first expansion section 12 and the second expansion section 15. A first suspension sealing structure 40 and a second suspension sealing structure 50, identical in size to the actual expansion tubing, were installed outside the simulated wellbore tool. Wellbore cleaning was performed to verify whether the composite expansion tubing could be successfully lowered into the well. After retrieval, the sealing structures were observed for damage to determine if the wellbore conditions were suitable for composite expansion tubing repair operations.

[0066] Then, the composite expansion tube 100 is lowered into...

[0067] Based on the inner diameter of the first expansion section 12 and the second expansion section 15, select a suitable feed drill bit 400 so that the feed drill bit 400 penetrates the second expansion cone 30 and the first expansion cone 20 in one go. It should be ensured that the feed drill bit 400 will not buckle during the lowering process, and that the tensile strength meets the lifting requirements during the expansion process.

[0068] Subsequently, the composite expansion tube was repaired using expansion patching.

[0069] After the composite expansion tube 100 is lowered into place, working fluid is injected into the drill bit 400 to form a hydraulic chamber in the first launching section 11. Under the action of hydraulic pressure, the first expansion cone 20 is driven to move upward, thereby causing the first expansion section 12 to expand. The first suspension sealing structure 40 hanging outside the first expansion section 12 is compressed, so that the first expansion section 12 is tightly attached to the inner wall of the small diameter section 230, forming a reliable seal. After the first expansion section 12 has fully expanded, the first expansion cone 20 reaches the second launching section 14 and is connected with the second expansion cone 30 to form a composite expansion cone. Under the continued action of hydraulic pressure, the composite expansion cone moves upward, causing the second expansion section 15 to expand. The second suspension sealing structure 50 outside the second expansion section 15 is compressed, so that the second expansion section 15 is tightly attached to the inner wall of the large diameter section 210, forming a reliable seal, thus completing the expansion process of the composite expansion tube.

[0070] Finally, communicate with the well.

[0071] The bottom accessory of the pipe body 10 was milled using a milling tool to connect the wellbore passage and obtain the repaired new wellbore 500. At this time, the repair work of the composite production casing 200 was completed.

[0072] The detailed explanations of the above embodiments are intended only to explain the present invention so as to facilitate a better understanding of the present invention. However, these descriptions should not be construed as limiting the present invention for any reason. In particular, the various features described in different embodiments can be arbitrarily combined with each other to form other embodiments. Unless there is an explicit description to the contrary, these features should be understood to be applicable to any embodiment, and not limited to the described embodiments.

Claims

1. A composite expansion tube, characterized in that, The composite expansion tube includes: The tube body includes, in an axial sequence, a first launching section, a first expansion section, an enlarged diameter section, a second launching section, and a second expansion section; A first expansion cone is disposed within the first emission section. The outer diameter of the first expansion cone is larger than the inner diameter of the first expansion section and can move into the first expansion section to cause the first expansion section to expand outward. A second expansion cone is disposed within the second launching section. The outer diameter of the second expansion cone is larger than the inner diameter of the second expansion section, and the second expansion cone can move into the second expansion section and cause the second expansion section to expand outward. The outer diameter of the second expansion cone is larger than the outer diameter of the first expansion cone.

2. The composite expansion tube as described in claim 1, characterized in that, The tube body is closed at one end of the first transmitting section and open at the other end. The first expansion cone and the second expansion cone each have an installation cavity that extends through the axial direction of the tube body. The first expansion cone is in a sealing sliding fit with the inner wall of the first transmitting section, and the second expansion cone is in a sealing sliding fit with the inner wall of the second transmitting section.

3. The composite expansion tube as described in claim 2, characterized in that, The first expansion cone has a first mating structure at one end facing the expansion section, and the second expansion cone has a second mating structure at one end facing the expansion section. The first mating structure and the second mating structure are aligned and fitted together.

4. The composite expansion tube as described in claim 1, characterized in that, The inner diameter of the second expansion section is larger than the inner diameter of the first expansion section.

5. The composite expansion tube as described in claim 1, characterized in that, The first expansion section outer sleeve is provided with a first suspension sealing structure, and the second expansion section outer sleeve is provided with a second suspension sealing structure.

6. A wellbore repair and reconstruction method based on a composite expansion tube, wherein the composite expansion tube is the composite expansion tube according to any one of claims 1 to 5, characterized in that, The wellbore repair and reconstruction method includes: Calculate the size parameters of the composite expansion pipe based on the size parameters of the downhole composite casing and the location of the casing damage point, and then manufacture the composite expansion pipe. The composite expansion pipe is placed downhole, with the second expansion section and the first expansion section positioned above and below the casing damage point, respectively. The first expansion cone is pushed to move to the first expansion section, causing the first expansion section to expand outward and fit tightly against the inner wall of the composite sleeve. The second expansion cone is pushed to move to the second expansion section and the second expansion section expands outward and fits tightly against the inner wall of the composite sleeve.

7. The wellbore repair and reconstruction method based on composite expansion tube as described in claim 6, characterized in that, The composite sleeve includes a large-diameter section, a reduced-diameter section, and a small-diameter section arranged sequentially from top to bottom. The first expansion section is aligned and tightly attached to the inner wall of the small-diameter section, and the second expansion section is aligned and tightly attached to the inner wall of the large-diameter section.

8. The wellbore repair and reconstruction method based on composite expansion tube as described in claim 6, characterized in that, The dimensional parameters of the composite expansion tube include the outer diameter, wall thickness, and inner diameter after expansion of the first expansion section, as well as the outer diameter, wall thickness, and inner diameter after expansion of the second expansion section.

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