Well cementation sealing compensation device

Abstract

The invention discloses a well cementation sealing compensation device. The method comprises the steps that limiting bosses are arranged at the two ends of a framework body respectively, and at least one hole is formed in the framework body; the framework body is sleeved with the protective sleeve, and the two ends of the protective sleeve are limited through limiting bosses. And the vulcanized colloid is filled between the outer wall of the framework body and the protective sleeve and on the inner wall of the framework body. The auxiliary sealing device can assist in well cementation conveniently and efficiently at low cost, achieves the sealing effect, provides a new auxiliary sealing method for solving the problem of annulus pressure caused by oil-gas-water channeling caused by cement sheath micro-ring gaps / insufficient cementation, effectively relieves the problem of annulus pressure, and accordingly improves well cementation quality, prolongs the service life of a shaft and guarantees well control safety of oil and gas fields.

Description

Technical Field

[0001] The present invention relates to the technical field of tools for cementing engineering, and particularly to a cementing seal compensation device. Background Art

[0002] With the continuous increase in the demand for natural gas, the number of gas wells and the construction of gas storage wells are growing continuously. Due to phenomena such as casing damage, poor cementing quality, and cement sheath sealing failure caused by changes in downhole environment during the exploration process, the problem of annulus pressure buildup is becoming increasingly prominent. For gas wells, the annulus pressure buildup problem is likely to cause high-pressure gas leakage, resulting in the inability of gas wells to produce normally and a decrease in gas production. In severe cases, there is even a risk of out-of-control, posing a great hidden danger to the well control safety of oil and gas fields. For oil and gas wells, the annulus pressure buildup problem affects oil and gas production, posing a great threat to the safety of wellhead equipment and operating personnel, and is difficult and costly to deal with in the later stage.

[0003] In order to reduce the various risks brought by the annulus pressure buildup problem, the prior art mainly improves the cementing quality from two aspects. First: improving the displacement efficiency, drilling fluid performance, and cement slurry performance; Second: using sealing tools to prevent the failure of the cement sheath (for example, the sealing tools can be selected from top packer tailpipe hangers, packer tie-back plugs, compression packers, hydraulic expansion packers, and oil / water-swelling packers, etc.) to prevent the occurrence of oil / gas / water channeling phenomena and extend the life of the well. Although installing sealing tools on the pipe string can solve the annulus pressure buildup problem to a certain extent, if the installation quantity is small, it cannot meet the requirements of complex downhole conditions. If the installation quantity is too large, not only will the pipe string stiffness increase, making it difficult to run in hole and affecting the integrity of the pipe string, but also the cost will be too high. Therefore, it is very necessary to provide a sealing compensation device with low cost and little impact on the integrity of the pipe string. Summary of the Invention

[0004] The inventors of the present invention found that due to reasons such as casing damage, poor cementing quality, or changes in downhole environment, the cement sheath sealing failure will occur, resulting in the annulus pressure buildup problem, which not only seriously affects oil and gas production but also poses a great hidden danger to the well control safety of gas fields. The prior art realizes the sealing function by installing conventional packers on the pipe string to prevent the oil / gas / water channeling phenomenon caused by the failure of the cement sheath. However, if the number of installed packers is small, it cannot meet the requirements of complex downhole conditions. If the number of installed packers is too large, not only will the pipe string have a large stiffness and be difficult to run in hole, but also the cost will be too high, affecting the integrity of the entire pipe string. In view of the above problems, the inventors of the present invention provide a cementing seal compensation device that overcomes the above problems or at least partially solves the above problems.

[0005] In a first aspect, an embodiment of the present invention provides a cementing seal compensation device, including: a skeleton body, a protective sleeve, and a vulcanized colloid;

[0006] Limit convex platforms are respectively arranged at both ends of the skeleton body, and at least one hole is formed in the skeleton body;

[0007] The protective sleeve is sleeved on the skeleton body, and both ends are limited by the limit convex platforms;

[0008] The vulcanized colloid is filled between the outer wall of the skeleton body and the protective sleeve and on the inner wall of the skeleton body.

[0009] In one embodiment, forming at least one hole in the skeleton body includes: at least one cross-section convex platform is arranged on the skeleton body, and the hole is formed on the cross-section convex platform.

[0010] In one embodiment, it further includes: a sealing groove and a sealing element;

[0011] The sealing grooves are respectively arranged at both ends of the inner wall of the skeleton body and located at the limit convex platforms;

[0012] The sealing element is arranged in the sealing groove.

[0013] In one embodiment, it further includes an end ring;

[0014] The end ring is threadedly connected to the skeleton body and is arranged at one end of the skeleton body, and the end ring is used to fix the protective sleeve.

[0015] In one embodiment, a plurality of holes are formed in the protective sleeve.

[0016] In one embodiment, the plurality of holes are distributed along the axial direction of the protective sleeve.

[0017] In one embodiment, the skeleton body is an integrally formed structure.

[0018] In a second aspect, an embodiment of the present invention provides a cementing tool, including: a first limit ring, a second limit ring, and the aforementioned cementing seal compensation device;

[0019] The first limit ring, the cementing seal compensation device, and the second limit ring are sequentially arranged on the casing.

[0020] In one embodiment, the cementing tool further includes a limit screw; the limit screw is used to fix the first limit ring or the second limit ring.

[0021] In a third aspect, an embodiment of the present invention provides a cementing sealing method, which is characterized in that it is realized by using the aforementioned cementing tool, including:

[0022] Setting the cementing tool on the casing, lowering it to a preset well depth, and realizing the seal between the cementing tool, the cement sheath, and the casing in the case of oil and gas water channeling.

[0023] The beneficial effects of the above technical solution provided by the embodiment of the present invention at least include:

[0024] The cementing seal compensation device provided by the embodiment of the present invention includes a skeleton body, a protective sleeve and a vulcanized colloid; limiting bosses are respectively arranged at both ends of the skeleton body, holes are also formed in the skeleton body, the protective sleeve is sleeved on the skeleton body, and both ends of the protective sleeve are limited by the limiting bosses. The vulcanized colloid is filled between the outer wall of the skeleton body and the protective sleeve. When the oil, gas and water flow up and contact the vulcanized colloid, the vulcanized colloid will expand automatically to realize the seal between the cementing seal compensation device and the cement sheath. The vulcanized colloid is also filled on the inner wall of the skeleton body. If the oil, gas or water on one side of the inner wall of the skeleton body flows up, it can contact the vulcanized colloid on the inner wall of the skeleton body and be absorbed to realize the seal between the cementing seal compensation device and the casing. The cementing seal compensation device adopts a vulcanization process to vulcanize the colloid on the inner and outer surfaces of the skeleton body, and is lowered into the designed well depth with the casing and normal cementing. During the development process, if microcracks occur in the cement sheath cementation and oil, gas and water flow up, when the oil, gas and water flow up to the cementing seal compensation device, they are absorbed by the vulcanized colloid of the cementing seal compensation device, and their own volume will expand, so as to fill and seal the annulus, realize the seal between the cementing seal compensation device and the outer cement sheath and the casing, effectively prevent the further flow up of oil, gas and water, and reduce the risk of annulus pressure.

[0025] Moreover, a cross-section boss is arranged on the skeleton body, and at least one hole is formed in the cross-section boss, so that the vulcanized colloid can enter the skeleton body from the hole and be filled in the skeleton body, so that the oil, gas or water flowing up on one side of the inner wall of the skeleton body can also contact the vulcanized colloid and be absorbed by the vulcanized colloid, further preventing the flow up of oil, gas and water and realizing the seal between the cementing seal compensation device and the casing.

[0026] In addition, the cementing seal compensation device provided by the embodiment of the present invention further includes a sealing groove and a sealing member. The sealing grooves are respectively arranged at both ends of the inner wall of the skeleton body, and the sealing members are arranged in the sealing grooves. The flowing-up oil, gas and water first reach the sealing groove at the lower end of the cementing seal compensation device and are blocked by the sealing members in the sealing groove, realizing the first layer of seal between the cementing seal compensation device and the casing. The unblocked oil, gas and water continue to flow up, contact the vulcanized colloid and are absorbed, realizing the second layer of seal between the cementing seal compensation device and the casing. The unabsorbed oil, gas and water continue to flow up to the sealing groove at the upper end of the cementing seal compensation device and are blocked by the sealing members in the sealing groove, realizing the third layer of seal between the cementing seal compensation device and the casing. Through multiple layers of sealing, the problem of oil, gas and water flow through caused by micro-annular clearance or under-cementation of the cement sheath is solved, thereby alleviating the problem of annulus pressure.

[0027] Other features and advantages of the present invention will be set forth in the following description, and in part will be obvious from the description, or may be learned by practice of the present invention. The objectives and other advantages of the present invention may be realized and attained by the structure particularly pointed out in the written description, claims, as well as the drawings.

[0028] The technical solutions of the present invention will be further described in detail below with reference to the drawings and embodiments. Description of the Drawings

[0029] The drawings are used to provide a further understanding of the present invention, and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention, but do not constitute a limitation to the present invention. In the drawings:

[0030] Figure 1 is a schematic structural diagram of the cementing seal compensation device in the embodiment of the present invention;

[0031] Figure 2-1 is a sectional view of the framework body in the embodiment of the present invention;

[0032] Figure 2-2 is a schematic structural diagram of the framework body in the embodiment of the present invention;

[0033] Figure 3 is one of the sectional views of the framework body in the embodiment of the present invention;

[0034] Figure 4 is another sectional view of the framework body in the embodiment of the present invention;

[0035] Figure 5 is a schematic structural diagram of the end ring in the embodiment of the present invention;

[0036] Figure 6 is a schematic structural diagram of the protective sleeve in the embodiment of the present invention;

[0037] Figure 7 is a schematic structural diagram of the cementing seal compensation device in the assembled state in the embodiment of the present invention;

[0038] Figure 8 is a schematic structural diagram of the cementing tool in the embodiment of the present invention.

[0039] Reference Signs:

[0040] 31 - First seal; 32 - Framework body; 33 - Protective sleeve; 34 - Vulcanized colloid; 35 - Second seal; 36 - Lower joint 36;

[0041] 1 - Casing; 2 - First limit ring; 3 - Cementing seal compensation device; 4 - Second limit ring; 5 - Limit screw 5. Detailed Embodiments

[0042] Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided so that the present disclosure can be more thoroughly understood and the scope of the present disclosure can be completely conveyed to those skilled in the art.

[0043] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation of the invention. In addition, the terms "first", "second", and "third" are only used for descriptive purposes and should not be construed as indicating or implying relative importance.

[0044] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "mounted", "connected", and "connected" 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 directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0045] The inventors of the present invention have found that due to reasons such as casing damage, poor cementing quality, or changes in downhole environment, the cement sheath sealing failure will occur, resulting in the problem of annulus pressure, which not only seriously affects the oil and gas production, but also poses a great hidden danger to the well control safety of oil and gas fields. The existing methods for improving cementing quality are inefficient and costly. To solve the problems existing in the prior art, an embodiment of the present invention provides a cementing seal compensation device, the structure of which is as Figure 1 shown, including a skeleton body 32, a protective sleeve 33, and a vulcanized colloid 34;

[0046] Limit bosses are respectively arranged at both ends of the skeleton body 32, and at least one hole is opened on the skeleton body 32;

[0047] The protective sleeve 33 is sleeved on the skeleton body 32, and both ends are limited by the limit bosses;

[0048] The vulcanized colloid 34 is arranged between the outer wall of the skeleton body 32 and the protective sleeve 33 and on the inner wall of the skeleton body 32.

[0049] The cementing seal compensation device uses a vulcanization process to produce a vulcanized colloid 34. The colloid selects a material that can expand when encountering oil, gas or water. The vulcanized colloid 34 is filled between the skeleton body 32 and the protective sleeve 33 to ensure that there is no gap between the skeleton body 32 and the protective sleeve 33 and it is in a sealed state in case of oil, gas and water upwelling. The vulcanized colloid 34 is also filled on the inner wall of the skeleton body 32 to ensure that there is no gap between the inner wall of the skeleton body 32 and the casing in case of oil, gas and water upwelling. The cementing seal compensation device is lowered into the designed well depth with the casing and normal cementing is carried out. During the development process, if microcracks occur in the cement sheath bonding and oil, gas and water upwelling phenomenon occurs, when the oil, gas and water upwell to the cementing seal compensation device, they are absorbed by the vulcanized colloid 34 of the cementing seal compensation device, and its own volume will expand, so as to fill and seal the annulus, realize the seal between the cementing seal compensation device and the outer cement sheath and the casing, effectively prevent the further upwelling of oil, gas and water, and reduce the risk of annulus pressure.

[0050] Among them, the skeleton body 32 is an integrally formed structure and adopts an overall processing technology, making the skeleton body 32 have higher strength. The limiting bosses at both ends of the skeleton body 32 are higher than the middle position, forming a structure with thick ends and thin middle. The protective sleeve 33 is limited by the limiting bosses, and the end face of the colloid can also be protected by the limiting bosses to prevent the rubber surface from being scratched during transportation and well entry.

[0051] In some alternative embodiments, at least one cross-section boss is provided on the skeleton body, and holes are opened on the cross-section boss. At least one hole is opened on the cross-section boss, so that the vulcanized colloid 34 can also expand by itself after contacting with oil, gas or water on one side of the inner wall of the skeleton body 32. Refer to Figure 2-1 as shown. Figure 2-1 is the cross-sectional view of the skeleton body. The inner wall of the skeleton body at the cross-section boss is slightly higher. Refer to Figure 2-2 as shown. Uniform elliptical holes are designed in the three cross-section boss areas of A, I and II respectively. There are limiting bosses at both ends of the cross-section boss A, a limiting boss at one end of the cross-section boss I close to the cross-section boss A, and a limiting boss at one end of the cross-section boss II close to the cross-section area A. The colloid is integrally vulcanized on the skeleton body 32 through the vulcanization process, so that the oil, gas and water on both the inner and outer sides of the skeleton body 32 can contact the colloid. Refer to Figure 3 and Figure 4 as shown. Figure 3 represents the cross-section of the skeleton body 32 filled with the vulcanized colloid 34 at the cross-section boss A, the cross-section boss I or the cross-section boss II. Figure 4 represents the cross-sectional view of the skeleton body 32 filled with the vulcanized colloid 34 at the position between the cross-section boss A and the cross-section boss I or the position between the cross-section boss A and the cross-section boss II.

[0052] It should be noted that the vulcanized colloid on the inner wall of the skeleton body, that is, the vulcanized colloid at the cross-sectional boss, is flush with the inner wall of the skeleton body after the vulcanized colloid is formed. The vulcanized colloid on the outer wall of the skeleton body is flush with the height of the limiting boss after being formed. In other words, the inner sides of the skeleton bodies filled with the vulcanized colloid have the same height, and the outer sides have the same height, forming a cylindrical shape.

[0053] In addition, still referring to Figure 1 As shown, one end of the skeleton body 32 close to the lower joint 36 is provided with a straight thread, and the straight thread is located between the limiting boss and the lower joint 36.

[0054] The well cementing seal compensation device provided by the embodiment of the present invention further includes a sealing groove and a sealing member (not shown in the figure);

[0055] The sealing grooves are respectively arranged at both ends of the inner wall of the skeleton body 32, at the position of the limiting boss;

[0056] The sealing member is arranged in the sealing groove.

[0057] Sealing grooves are respectively arranged at both inner ends of the skeleton body 32, and sealing members are arranged in the sealing grooves to play a sealing role. Still referring to Figure 2, if an annulus appears between the well cementing seal compensation device and the casing, the upwelling oil, gas and water will reach the sealing member (the first sealing member 31) at one end of the well cementing seal compensation device close to the lower joint 36 in turn, the cross-sectional boss II, the cross-sectional boss A, the cross-sectional boss I and the sealing member (the second sealing member 35) at the other end of the well cementing seal compensation device. Correspondingly, the sealing groove for setting the first sealing member 31 is the first sealing groove, and contact the vulcanized colloid 34 on the inner side of the skeleton body 32 and be absorbed. In other words, five layers of seals are arranged between the well cementing seal compensation device and the casing, namely the first sealing member 31, the vulcanized colloid 34 of the cross-sectional boss II, the vulcanized colloid 34 of the cross-sectional boss A, the vulcanized colloid 34 of the cross-sectional boss I and the second sealing member 35, so as to ensure the sealing performance between the well cementing seal compensation device and the casing.

[0058] The well cementing seal compensation device provided by the embodiment of the invention further includes an end ring;

[0059] The end ring is threadedly connected to the skeleton body 32 and is arranged at one end of the skeleton body 32. The end ring is used to fix the protective sleeve 33. As Figure 5 shown in the schematic diagram of the end ring, specifically, the end ring is connected to the straight thread of the skeleton body 32.

[0060] The protective sleeve 33 is sleeved on the skeleton body 32 and is limited by the limiting boss on the skeleton body 32, which can ensure the safe lowering of the vulcanized colloid 34. Preferably, the thickness of the protective sleeve 33 is 0.5 mm - 1 mm.

[0061] In addition, a number of holes are provided on the protective sleeve 33. Refer to Figure 6 As shown, a number of holes are staggered. While ensuring the safe lowering of the vulcanized colloid 34, it can prevent the vulcanized colloid 34 from expanding too fast. The shape and size of the holes can be designed according to the actual situation, and can be square holes, round holes, etc. The sizes of the holes do not have to be exactly the same, and the embodiments of the present invention do not limit this.

[0062] In some alternative embodiments, it should be noted that a number of holes on the protective sleeve 33 are distributed along the axial direction of the protective sleeve 33. When the cementing seal compensation device is implemented, it is lowered into the well with the casing to a preset well depth. When oil, gas, and water flow upward, in order to enable the oil, gas, and water to come into contact with the vulcanized colloid 34 with a higher probability during the upward flow process, holes are opened along the axial direction of the protective sleeve 33. In other words, holes of staggered sizes are distributed along the axial direction of the protective sleeve 33.

[0063] Schematic diagram of the cementing seal compensation device in the assembled state. Refer to Figure 7 As shown.

[0064] Based on the same inventive concept, the embodiments of the present invention also provide a cementing tool. In the assembled state, it is as shown in Figure 8 As shown, it includes: a first limiting ring 2, a second limiting ring 4, and the aforementioned cementing seal compensation device 3;

[0065] The first limiting ring 2, the cementing seal compensation device 3, and the second limiting ring 4 are sequentially arranged on the casing 1.

[0066] The embodiments of the present invention also provide a cementing tool, which further includes a limiting screw 5.

[0067] Specifically, during the on-site implementation process, first install the first limiting ring 2 on the casing 1 and fix it with the limiting screw 5. Then, sleuth the cementing seal compensation device 3 on the casing 1. Finally, install the second limiting ring 4 on the casing 1 and fix it with the limiting screw 5. The second limiting ring 4 is located at the end close to the drill bit.

[0068] Based on the same inventive concept, the embodiments of the present invention also provide a cementing seal method, which is implemented using the aforementioned cementing tool and includes:

[0069] Set the cementing tool on the casing 1 and lower it to the preset well depth to achieve the seal between the cementing tool, the cement sheath, and the casing 1 in the case of oil, gas, and water flowing upward.

[0070] During the later oil and gas production process, if the cement sheath bonding quality is poor and micro-cracks appear, causing oil, gas, and water to migrate upward, the upward-migrating oil, gas, and water reach the cementing tool, and are absorbed by the vulcanized colloid 34 in the cementing seal compensation device 3 of the cementing tool to prevent further upward migration of oil, gas, and water. After the vulcanized colloid 34 expands, it realizes sealing with the outer cement sheath and the casing 1, effectively preventing the upward migration of oil, gas, and water and reducing the risk of annulus pressure buildup.

[0071] Unless specifically stated otherwise, terms such as processing, computing, calculating, determining, displaying, etc. can refer to the actions and / or processes of one or more processing or computing systems, or similar devices, which operate on and transform data represented as physical (such as electronic) quantities within the registers or memories of the processing system into other data similarly represented as physical quantities within the memories, registers, or other such information storage, transmission, or display devices of the processing system. Information and signals can be represented using any of a variety of different technologies and methods. For example, the data, instructions, commands, information, signals, bits, symbols, and chips mentioned throughout the above description can be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

[0072] It should be understood that the specific order or hierarchy of steps in the disclosed processes is an example of an exemplary method. Based on design preferences, it should be understood that the specific order or hierarchy of steps in the process can be rearranged without departing from the scope of the present disclosure. The appended method claims present the elements of the various steps in an exemplary order and are not intended to be limited to the specific order or hierarchy recited.

[0073] In the above detailed description, various features are combined in a single embodiment to simplify the present disclosure. This method of disclosure should not be interpreted as reflecting an intention that the embodiments of the claimed subject matter require more features than are expressly recited in each claim. On the contrary, as reflected in the appended claims, the present invention resides in less than all of the features of a single disclosed embodiment. Accordingly, the appended claims are hereby expressly incorporated into the detailed description, where each claim stands on its own as a separate preferred embodiment of the present invention.

[0074] The foregoing description includes examples of one or more embodiments. Of course, it is not possible to describe all possible combinations of components or methods for the purpose of describing the above embodiments, but those of ordinary skill in the art should recognize that the various embodiments can be further combined and arranged. Accordingly, the embodiments described herein are intended to embrace all such alterations, modifications, and variations that fall within the scope of the appended claims. Further, with respect to the term "comprising" used in the specification or claims, the term is inclusive in a manner similar to the term "including" as interpreted when used as a transitional word in a claim. Additionally, any use of the term "or" in a claim or the specification is to be meant "non-exclusive or".

Claims

1. A cementing seal compensation device, characterized in that, Comprising: A skeleton body, a protective sleeve and a vulcanized colloid; Limit bosses are respectively arranged at two ends of the skeleton body, and at least one hole is formed in the skeleton body; The protective sleeve is sleeved on the skeleton body, and both ends are limited by the limit bosses; The vulcanized colloid is filled between the outer wall of the skeleton body and the protective sleeve and on the inner wall of the skeleton body.

2. The cementing seal compensation device according to claim 1, characterized in that At least one hole is formed in the skeleton body, including: at least one cross-section boss is arranged on the skeleton body, and the hole is formed on the cross-section boss.

3. The cementing seal compensation device according to claim 1, characterized in that Further comprising: A sealing groove and a sealing member; The sealing grooves are respectively arranged at two ends of the inner wall of the skeleton body at the positions of the limit bosses; The sealing member is arranged in the sealing groove.

4. The cementing seal compensation device according to claim 1, characterized in that, Further comprising end rings; The end rings are threadedly connected with the skeleton body and are arranged at one end of the skeleton body, and the end rings are used to fix the protective sleeve.

5. The cementing seal compensation device according to claim 1, characterized in that A plurality of holes are formed in the protective sleeve.

6. The cementing seal compensation device according to claim 5, wherein, The plurality of holes are distributed along the axial direction of the protective sleeve.

7. The cementing seal compensation device according to claim 1, characterized in that, The skeleton body is of an integrally formed structure.

8. A cementing tool, characterized in that, Comprising: A first limit ring, a second limit ring and the primary cementing seal compensation device according to any one of claims 1-7; The first limit ring, the primary cementing seal compensation device and the second limit ring are sequentially arranged on the casing.

9. The cementing tool according to claim 8, wherein, Further comprising limit screws; the limit screws are used to fix the first limit ring or the second limit ring.

10. A method for well cementing and sealing, characterized in that, Realized by using the primary cementing tool according to any one of claims 8-9, including: Arranging the primary cementing tool on the casing, lowering it to a preset well depth, and realizing the seal between the primary cementing tool, the cement sheath and the casing in the case of oil and gas water channeling.

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