Integrated anti-deformation local double-layer sleeve device

Abstract

The invention relates to the technical field of casing pipes for exploration and development of conventional and unconventional oil and gas fields, in particular to an integrated casing-deformation-preventing local double-layer casing pipe device. The integrated anti-deformation local double-layer sleeve device comprises an outer-layer anti-deformation sleeve and an inner sleeve, an annular cavity is formed in the side wall of the outer-layer anti-deformation sleeve, an anti-extrusion body is arranged in the cavity, and the inner sleeve coaxially penetrates through the outer-layer anti-deformation sleeve and is detachably connected with the outer-layer anti-deformation sleeve. The device has the advantages that the structural design is simple and reasonable, the outer-layer anti-deformation sleeve is prefabricated and can be directly installed and used on site, matched production can be achieved according to different requirements, the device does not change the inner sleeve connection form and the body structure, and in addition, compared with a traditional double-layer sleeve, the hanging load of the whole sleeve can be obviously reduced.

Description

Technical Field

[0001] The invention relates to the technical field of casing used in conventional and unconventional oil and gas field exploration and development, and in particular to an integrated casing change prevention local double-layer casing device. Background Art

[0002] Casing is mainly used to isolate easily collapsed and leaky formations, separate reservoirs with different pressures, create safe migration channels for the production layers, and ensure long-term stable production. With the deepening of domestic oil and gas production and development, on-site casing damage problems occur frequently, and casing changes often occur in gypsum layers and nearby formations or in the shale gas fracturing process. The main cause of casing changes is local slippage of the formation, and its shear and squeezing effect causes the casing to deform. Casing damage will have a great impact on on-site production and development. The integrity of the casing is of great significance to the safe and stable production of oil and gas wells.

[0003] As the country intensifies its efforts in the exploration and development of new energy sources, casing changes often occur in the exploration and development of new energy sources such as geothermal energy, coalbed methane, and combustible ice. The present invention can also be applied to the field of casing use involving unconventional resource development.

[0004] Active prevention of casing changes in advance can effectively reduce the risk of casing failure. Common methods for active prevention of casing in advance include: 1) using thick-walled casing; 2) using double-layer combined casing, with no cavity filling, or filling the cavity with hydraulic oil, cement slurry, or drilling fluid. The first method cannot improve the ability to resist uneven external loads, or the combined load capacity of uniform and uneven external loads; the second method is difficult to construct, increases the hanging weight of the casing, and increases the cementing cost. At the same time, the inner and outer casings of the double-layer casing need to be connected on site, and the connection is complicated. The existing inner casing needs to be processed to achieve the connection between the inner and outer casings. The connection is prone to failure and difficult to seal.

[0005] Based on this, it is necessary to develop a new integrated anti-casing change local double-layer casing device to overcome the above technical problems. Summary of the invention

[0006] The technical problem to be solved by the present invention is to provide an integrated anti-casing-change local double-layer casing device, which effectively overcomes the defects of the prior art.

[0007] The technical solution of the present invention to solve the above technical problems is as follows:

[0008] An integrated anti-casing change local double-layer casing device comprises an outer anti-casing change casing and an inner casing. A circular cavity is provided inside the side wall of the outer anti-casing change casing, an anti-extrusion body is provided in the cavity, and the inner casing coaxially passes through the outer anti-casing change casing and is detachably connected to each other.

[0009] Based on the above technical solution, the present invention can also be improved as follows.

[0010] Furthermore, the inner sleeve is provided with detachable positioning devices at the positions corresponding to the two ends of the outer sleeve preventing sleeve from being altered, and the outer sleeve preventing sleeve from being altered is clamped between the two positioning devices.

[0011] Furthermore, the positioning device comprises a circular stop ring, which is coaxially sleeved outside the inner sleeve and contacts the corresponding end of the outer anti-sleeve deformation sleeve. The stop ring is provided with a locking mechanism for locking or unlocking with the inner sleeve.

[0012] Furthermore, the locking mechanism includes a plurality of positioning pins, and the retaining ring is provided with a plurality of screw holes radially penetrating the retaining ring at intervals along its circumference. The surface of the positioning pin is provided with an external thread, and the positioning pin is screwed into the plurality of screw holes one by one. The positioning pin can be rotated until it contacts or separates from the inner sleeve.

[0013] Furthermore, washers are embedded at both ends of the outer anti-sleeve deformation sleeve.

[0014] Furthermore, the anti-extrusion body is an elastic anti-extrusion elasto-plastic body spirally coiled in the cavity.

[0015] Furthermore, the above-mentioned anti-extrusion elastic plastic body is made of polyethylene material and is formed on the inner wall of the above-mentioned cavity by hot winding.

[0016] Furthermore, the surface of the outer anti-sleeve change sleeve is provided with an air inlet connected to the cavity, a detachable plug is provided in the air inlet, and the cavity is filled with protective gas.

[0017] Furthermore, the protective gas is helium or nitrogen.

[0018] Furthermore, casing couplings are provided at both ends of the inner casing.

[0019] The beneficial effects of the present invention are: the structural design is simple and reasonable, the outer layer anti-sleeve change sleeve is prefabricated, can be directly installed and used on site, can be produced according to different needs, the device itself will not change the inner sleeve connection form and the main body structure, in addition, compared with the traditional double-layer sleeve, it can significantly reduce the hanging weight of the overall sleeve. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic structural diagram of the outer casing-change prevention casing in the integrated casing-change prevention local double-layer casing device of the present invention;

[0021] Figure 2 It is a structural schematic diagram of the integrated anti-casing-change local double-layer casing device of the present invention;

[0022] Figure 3It is a cross-sectional view of the stop ring of the integrated sleeve-changing partial double-layer sleeve device of the present invention;

[0023] Figure 4 It is a cross-sectional view of the stop ring of the integrated sleeve-changing prevention partial double-layer sleeve device of the present invention;

[0024] Figure 5 It is a cross-sectional view of another embodiment of the stop ring of the integrated sleeve-preventing partial double-layer sleeve device of the present invention;

[0025] Figure 6 A cross-sectional view of another embodiment of the stop ring of the integrated sleeve-preventing partial double-layer sleeve device of the present invention;

[0026] Figure 7 The cross-sectional view is another embodiment of the stop ring of the integrated sleeve-preventing partial double-layer sleeve device of the present invention.

[0027] In the accompanying drawings, the components represented by the reference numerals are listed as follows:

[0028] 1. Outer sleeve to prevent sleeve from changing into sleeve; 2. Inner sleeve; 3. Anti-extrusion body; 4. Positioning device; 21. Casing coupling; 41. Stop ring; 42. Locking mechanism. DETAILED DESCRIPTION

[0029] The principles and features of the present invention are described below in conjunction with the accompanying drawings. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0030] Example: Figure 1 , 2 As shown, the integrated anti-casing change local double-layer casing device of this embodiment includes an outer anti-casing change casing 1 and an inner casing 2. The outer anti-casing change casing 1 has a circular cavity inside its side wall, and an anti-extrusion body 3 is provided in the cavity. The inner casing 2 coaxially passes through the outer anti-casing change casing 1 and are detachably connected to each other.

[0031] In this embodiment, the inner casing 2 adopts various types of petroleum casing commonly used in existing projects. Specifically, the inner casing 2 is a standard casing, such as API casing, etc., including current casings of different steel grades, materials, and sizes used on-site in oil fields, without the need for additional processing and modification; the outer anti-casing change casing 1 is a hollow round tube, and a cavity with a sandwich layer (that is, a circular cavity) is provided inside the side wall, specifically a hollow double-layer concentric ring sealing device, which uses the same material, steel grade and wall thickness as the casing body. The hollow diameter of the outer anti-casing change casing 1 depends on the inner casing 2 used in combination. When using different inner casings 2, the hollow diameter range is adjusted according to the inner casing 2, and its length can be adjusted according to the length of the anti-casing change (the outer anti-casing change casing 1 of appropriate length is produced according to the use requirements before leaving the factory, and the internal anti-extrusion body 3 is also selected according to the use requirements. The outer diameter of the outer anti-casing change casing 1 is slightly smaller than the outer diameter of the casing straightener used. The entire technical solution has the following advantages:

[0032] 1) Processing of the outer casing change prevention casing 1 is realized in the factory to form an integrated casing change prevention local double-layer casing device that can be directly installed and used on site;

[0033] 2) The length of the outer anti-sheathing sleeve 1 is adjusted and adapted according to the needs;

[0034] 3) The inner casing connection form and the body structure are not changed, and the inner casing coupling connection method is retained;

[0035] 4) Compared with conventional double-layer casing cementing, it can effectively reduce the overall hanging weight of the casing.

[0036] As a preferred embodiment, the inner sleeve 2 is detachably provided with positioning devices 4 at the positions corresponding to the two ends of the outer sleeve 1 , and the outer sleeve 1 is sandwiched between the two positioning devices 4 .

[0037] In the above implementation scheme, the outer anti-sleeve change sleeve 1 is assembled in a relatively quick manner. It only needs to be sleeved on the inner sleeve 2 and then positioned by the positioning devices 4 at both ends. This is very conducive to quick disassembly and assembly on site, and shortens the construction period to a certain extent.

[0038] As a preferred embodiment, Figure 3 and 4 As shown, the positioning device 4 includes a circular stop ring 41, which is coaxially sleeved outside the inner sleeve 2 and contacts the corresponding end of the outer anti-sleeve deformation sleeve 1. The stop ring 41 is provided with a locking mechanism 42 for locking or unlocking with the inner sleeve 2.

[0039] In the above implementation scheme, when locking, the positioning device 4 is firstly sleeved on the outside of the inner sleeve 2, and then the outer anti-sleeve deformation sleeve 1 is positioned on the inner sleeve 2 through the locking mechanism 42 and the inner sleeve 2 is locked and matched, and the operation is very simple.

[0040] As a preferred embodiment, the locking mechanism 42 includes a plurality of positioning pins, and the stop ring 41 is provided with a plurality of screw holes (denoted by e in the figure) radially passing through it at intervals along its circumference. The surface of the positioning pin is provided with an external thread, and is screwed into the plurality of screw holes one by one. The positioning pin can be rotated to abut against or separate from the inner sleeve 2.

[0041] In the above embodiment, the locking mechanism 42 uses multiple positioning pins, which can be rotated into the screw holes of the stop ring 41 to abut against the inner sleeve 2, thereby achieving quick locking and ensuring the positioning of the outer anti-sleeve deformation sleeve 1 on the inner sleeve 2.

[0042] It should be noted that the stop rings 41 are used to fix the outer anti-sleeve change sleeve 1 at the desired anti-sleeve change position and connect the inner sleeve 2 with the outer anti-sleeve change sleeve 1. During installation, the upper stop ring 41 is first sleeved on the inner sleeve 2, and then the outer anti-sleeve change sleeve 1 is sleeved on the inner sleeve 2, and then the lower stop ring 41 is sleeved on the inner sleeve 2, and finally the upper and lower stop rings 41 are locked to fix the outer anti-sleeve change sleeve 1 on the inner sleeve 2.

[0043] In the integrated anti-casing partial double-layer casing device of this embodiment, the stop ring 41 can also be installed in several other structural forms:

[0044] 1) If Figure 5 As shown, external threads are arranged on the surface of the inner sleeve 2 corresponding to the two ends of the outer sleeve 1, and internal threads are arranged on the inner wall of the stop ring 41. The stop ring 41 is screwed together with the inner sleeve 2 and abuts against the end of the outer sleeve 1.

[0045] 2) If Figure 6 As shown, positioning keys (indicated by f in the figure) are arranged along the axial direction on the surface of the inner sleeve 2 corresponding to the two ends of the outer anti-sleeve change sleeve 1, and key grooves are arranged along the axial direction on the inner wall of the stop ring 41. The stop ring 41 is assembled by keying the limiter and the key groove. After assembly, the stop ring 41 abuts against the end of the outer anti-sleeve change sleeve 1.

[0046] 3) If Figure 7As shown, limit blocks (indicated by g in the figure) are provided at the positions of the inner sleeve 2 corresponding to the two ends of the outer anti-sleeve change sleeve 1, and a limit groove is provided on the inner side of the stop ring 41. After the stop ring 41 moves axially along the limit block until it abuts against the end of the outer anti-sleeve change sleeve 1, the stop ring 41 just breaks away from the limit block, and after the stop ring 41 is rotated, the end of the stop ring 41 abuts against the limit block, that is, the stop ring 41 is clamped between the limit block and the end of the outer anti-sleeve change sleeve 1.

[0047] In this embodiment, washers are embedded at both ends of the outer anti-sleeve change sleeve 1. The washers are flexible washers, which can improve the tightness of positioning and locking of the outer anti-sleeve change sleeve 1 to a certain extent.

[0048] In this embodiment, the anti-extrusion body 3 is an elastic anti-extrusion elastomeric body spirally wound in the cavity. The length, number of turns and thickness of the anti-extrusion body 3 are flexibly adjusted and adapted according to actual needs before leaving the factory, thereby adjusting the anti-extrusion performance of the outer anti-sleeve change sleeve 1.

[0049] In this embodiment, the anti-extrusion elastic plastic body is made of polyethylene and is formed on the inner wall of the cavity by hot winding. The hot-wound polyethylene can also be replaced by a similar solid with elastic-plastic properties.

[0050] As a preferred embodiment, the surface of the outer anti-sleeve change sleeve 1 is provided with an air inlet connected to the cavity, a detachable plug is provided in the air inlet, and the cavity is filled with protective gas.

[0051] In the above-mentioned embodiment, the inert gas is used to fill the remaining space outside the anti-extrusion body 3 in the outer anti-casing change casing 1, so as to enhance the anti-extrusion ability of the outer anti-casing change casing 1 and protect the internal structure of the outer anti-casing change casing 1. The inert gas can be an inert gas such as helium, nitrogen, or other gases with similar effects. The role of the gas is to improve the ability of the outer anti-casing change casing 1 to resist uneven external loads.

[0052] Of course, the air inlet may not be blocked, but it needs to be sealed and connected to an inflation nozzle, to which a control valve is connected, and the air inlet is opened or closed by opening or closing the valve.

[0053] It should be noted that in the integrated anti-casing change local double-layer casing device of the present embodiment, the outer anti-casing change casing 1 is a hollow cylinder, the hollow diameter of which depends on the inner casing 2 used in combination. When different inner casings 2 are used, the hollow diameter range is adjusted according to the inner casing 2, and its length can be adjusted according to the anti-casing change length. The outer diameter of the outer anti-casing change casing 1 should be slightly smaller than the outer diameter of the casing straightener used.

[0054] In this embodiment, both ends of the inner casing 2 are provided with casing couplings 21, which are used for docking with other pipelines. The overall device structure does not change the structure of the inner casing 2, and it is convenient to obtain materials.

[0055] In this embodiment, the inner casing 2 adopts various types of petroleum casings commonly used in existing projects, and there is no need to change the structure of the inner casing.

[0056] It should be noted that in this embodiment, the casing coupling 2121 is a connecting device for the inner casing 2, and is a common type of petroleum casing coupling in existing projects, and is used in conjunction with the inner casing 2 without changing the structure of the inner casing 2 and its connecting device.

[0057] The assembly method of the integrated anti-casing partial double-layer casing device of this embodiment is as follows:

[0058] Step 1: first connect the inner casing 2 by a conventional coupling connection method;

[0059] Step 2: When the casing is lowered into the well, firstly, the positioning device 4 located at the top is mounted on the inner casing 2 and locked;

[0060] Step 3: Then, the outer sleeve 1 is mounted on the inner sleeve 2, and the positioning device 4 on the upper and lower sides (that is, located at the lower end of the outer sleeve 1) is mounted and locked.

[0061] The entire installation method described above is very simple and can be installed directly on site without prior preparation.

[0062] The integrated anti-casing change local double-layer casing device of the present embodiment is aimed at the active prevention and treatment of early casing changes, and solves the problems existing in the prior art. During the whole process, the outer layer anti-casing change casing 1 is processed in the factory to form an integrated anti-casing change local double-layer casing device that can be directly installed and used on site; the length of the outer layer anti-casing change casing 1 is adjustable, the anti-extrusion capacity is variable (by adjusting the internal anti-extrusion body 3), and it is sealed once and for all, and the connection form and main body structure of the inner casing 2 are not changed; the connection mode of the casing coupling 21 is retained; the integrated anti-casing change local double-layer casing device filled with inert gas can improve the ability to resist uneven external loads; and at the same time reduce the suspended weight of the double-layer casing.

[0063] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0064] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0065] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0066] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0067] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0068] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. An integrated anti-casing partial double-layer casing device, characterized in that: The invention comprises an outer sleeve-deformation-preventing sleeve (1) and an inner sleeve (2), wherein a circular cavity is provided inside the side wall of the outer sleeve-deformation-preventing sleeve (1), an anti-extrusion body (3) is provided in the cavity, and the inner sleeve (2) coaxially passes through the outer sleeve-deformation-preventing sleeve (1) and the sleeves are detachably connected to each other.

2. The integrated anti-casing partial double-layer casing device according to claim 1, characterized in that: Positioning devices (4) are detachably mounted on the inner sleeve (2) at locations corresponding to the two ends of the outer sleeve-deformation-preventing sleeve (1), and the outer sleeve-deformation-preventing sleeve (1) is sandwiched between the two positioning devices (4).

3. The integrated anti-casing partial double-layer casing device according to claim 2, characterized in that: The positioning device (4) comprises a circular stop ring (41), which is coaxially sleeved outside the inner sleeve (2) and contacts the corresponding end of the outer anti-sleeve change sleeve (1). The stop ring (41) is provided with a locking mechanism (42) for locking or unlocking with the inner sleeve (2).

4. The integrated anti-casing partial double-layer casing device according to claim 3 is characterized in that: The locking mechanism (42) comprises a plurality of positioning pins. The stop ring (41) is provided with a plurality of screw holes radially penetrating the stop ring at intervals along its circumference. The positioning pin surface is provided with external threads and is screwed into the plurality of screw holes one by one. The positioning pin can be rotated to abut against or separate from the inner sleeve (2).

5. The integrated anti-casing partial double-layer casing device according to claim 2, characterized in that: Washers are embedded at both ends of the outer layer anti-sleeve deformation sleeve (1).

6. The integrated anti-casing partial double-layer casing device according to claim 1, characterized in that: The anti-extrusion body (3) is an elastic anti-extrusion elastomeric body spirally coiled in the cavity.

7. The integrated anti-casing partial double-layer casing device according to claim 6, characterized in that: The anti-extrusion elastic plastic body is made of polyethylene and is formed on the inner wall of the cavity by hot winding.

8. The integrated anti-casing partial double-layer casing device according to claim 6, characterized in that: The surface of the outer layer anti-sleeve change sleeve (1) is provided with an air inlet communicated with the cavity, a plug is detachably provided in the air inlet, and the cavity is filled with protective gas.

9. The integrated anti-casing partial double-layer casing device according to claim 8, characterized in that: The protective gas is helium or nitrogen.

10. An integrated anti-casing partial double-layer casing device according to any one of claims 1 to 9, characterized in that: Both ends of the inner sleeve (2) are respectively provided with sleeve couplings (21).

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