Reservoir protection cementing tools

Abstract

The present invention relates to the technical field of oil and gas cementing tools, and in particular to a reservoir protection cementing tool. The tool is arranged in a wellbore and forms a first annulus with the wellbore, comprising a pipe group and two main bodies detachably connected to the two ends of the pipe group; the pipe group comprises an outer pipe and an inner pipe, and the outer pipe is sleeved on the inner pipe; the main body comprises a connecting sleeve and a sealing assembly; the connecting sleeve is sleeved on the end of the inner pipe, and the end is connected to the outer pipe, an annular circulation channel is formed between the connecting sleeve, the outer pipe and the inner pipe, and a circulation hole connecting the first annulus and the circulation channel is opened on the connecting sleeve; the sealing assembly is arranged on the inner side of the circulation hole of the connecting sleeve, and the sealing assembly expands in the direction of the wellbore in an excited state to achieve flow interception. The present invention can effectively improve applicability and reduce use costs.

Description

Technical Field

[0001] The invention relates to the technical field of petroleum and natural gas cementing tools, in particular to a reservoir protection cementing tool. Background Art

[0002] In the process of cementing oil and gas wells, the contamination of reservoirs by cement slurry has always been a difficult problem to overcome. At present, most of the methods used at home and abroad are to optimize the performance of cement slurry to reduce the penetration of cement slurry filtrate into the reservoir, thereby achieving the purpose of reducing reservoir contamination. The effect is more obvious by using tools to make cement slurry bypass the reservoir and prevent cement slurry from contaminating the reservoir. However, due to the limitations of their structure, the existing tools of this type can only be applied to reservoirs of a specific length, so they have the problems of poor applicability and high cost of use. Summary of the invention

[0003] The purpose of the present invention is to provide a reservoir protection cementing tool to alleviate the technical problems of poor applicability and high use cost of existing reservoir protection tools.

[0004] In order to solve the above technical problems, the technical solution provided by the present invention is:

[0005] The reservoir protection cementing tool provided by the present invention is arranged in a wellbore and forms a first annulus with the wellbore, and comprises a pipe group and two main bodies detachably connected to both ends of the pipe group;

[0006] The tube group includes an outer tube and an inner tube, and the outer tube is sleeved on the inner tube;

[0007] The main body includes a connecting sleeve and a packing assembly;

[0008] The connecting sleeve is sleeved on the end of the inner tube, and the end is connected to the outer tube, an annular circulation channel is formed between the connecting sleeve, the outer tube and the inner tube, and a circulation hole connecting the first annulus and the circulation channel is opened on the connecting sleeve;

[0009] The isolation assembly is arranged on the inner side of the circulation hole of the connecting sleeve, and the isolation assembly expands toward the wellbore in an excited state to realize flow cutoff.

[0010] Furthermore, the connecting sleeve includes a first connecting portion and a second connecting portion connected to each other;

[0011] The first connecting portion is sleeved on the end of the inner tube and communicated with the inner tube;

[0012] One end of the second connecting part is in contact with the first connecting part, and the other end is in contact with the outer tube to form a continuous tube wall, and a circulation channel is formed between the continuous tube wall and the inner tube.

[0013] Furthermore, a boss is provided in the area near the circulation hole of the second connecting portion;

[0014] The second connecting portion is connected to the outer pipe via a coupling, and an accommodating space for accommodating the packing assembly is formed between the boss and the coupling.

[0015] Furthermore, a flow channel hole is provided on the side of the boss close to the sealing assembly, and the flow channel hole is communicated with the first hydraulic channel.

[0016] Furthermore, the first hydraulic channel includes a first flow channel and a second flow channel that are interconnected;

[0017] The first flow channel is arranged inside the first connecting portion, the inlet is arranged on the inner wall of the first connecting portion, and the outlet is arranged on the inner end surface of the first connecting portion;

[0018] The second flow channel is arranged inside the second connecting portion, the inlet of the second flow channel is connected to the outlet of the first flow channel, and the outlet is connected to the flow channel hole.

[0019] Furthermore, the packing assembly includes a piston, a connecting sleeve and a packing sleeve;

[0020] The connecting part of the piston is arranged on the upper surface of the boss, the main body is located on the side of the boss, and the piston can slide along the axial direction;

[0021] One end of the connecting sleeve is connected to the piston, and the other end is connected to the packing sleeve;

[0022] The end of the packing sleeve facing away from the connecting sleeve abuts against the coupling.

[0023] Furthermore, the connecting portion is connected to the boss via a shear pin.

[0024] Furthermore, a serrated stop ring is embedded in the inner surface of the connecting sleeve, and a serrated structure matching the serrated stop ring is provided on the second connecting portion.

[0025] Furthermore, a limiting ring is sleeved on the side of the sawtooth structure on the second connecting part away from the sawtooth stop ring, and a groove cooperating with the limiting ring is provided on the side of the sawtooth stop ring on the connecting sleeve close to the sawtooth structure.

[0026] Furthermore, a swirl generator is arranged on the outer wall of the inner tube, and the swirl generator is arranged as a spiral structure.

[0027] Based on the above technical solutions, the technical effects that can be achieved by the present invention are analyzed as follows:

[0028] A reservoir protection cementing tool is arranged in a wellbore and forms a first annulus with the wellbore, comprising a pipe group and two main bodies detachably connected to both ends of the pipe group;

[0029] The tube group includes an outer tube and an inner tube, and the outer tube is sleeved on the inner tube;

[0030] The main body includes a connecting sleeve and a packing assembly;

[0031] The connecting sleeve is sleeved on the end of the inner tube, and the end is connected to the outer tube, an annular circulation channel is formed between the connecting sleeve, the outer tube and the inner tube, and a circulation hole connecting the first annulus and the circulation channel is opened on the connecting sleeve;

[0032] The isolation assembly is arranged on the inner side of the circulation hole of the connecting sleeve, and the isolation assembly expands toward the wellbore in an excited state to realize flow cutoff.

[0033] When working, the cementing tool moves to the position corresponding to the reservoir position, and starts the sealing components at both ends to seal the first annulus between the cementing tool and the reservoir. When mud flows out from one end of the channel inside the cementing tool to the first annulus for cementing, under the action of the sealing component, the overflowed mud can only enter the circulation channel and return to the first annulus outside the other end of the cementing tool to continue cementing, thereby achieving the effect of bypassing the reservoir.

[0034] Since the sealing assembly is arranged on the connecting sleeve, when the length of the reservoir to be protected does not match the preset length of the cementing tool, there is no need to re-produce the entire cementing tool. Instead, the main body can be mounted on a pipe group of other lengths to change the length of the reservoir that can be protected by the cementing tool, thereby effectively improving the applicability of the cementing tool and reducing the cost of use. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0036] Figure 1 It is a structural schematic diagram of the present invention;

[0037] Figure 2 It is a partial structural schematic diagram of the present invention;

[0038] Figure 3 It is a structural schematic diagram of the sawtooth stop ring and the sawtooth structure of the present invention;

[0039] Figure 4 It is a schematic structural diagram of a swirl generator of the present invention;

[0040] Icon: 100-pipe group; 200-main body; 300-circulation hole; 400-coupling; 500-first hydraulic channel; 600-serrated stop ring; 700-serrated structure; 800-limiting ring; 900-shear pin; 1000-swirl generator;

[0041] 110-outer tube; 120-inner tube; 210-connecting sleeve; 220-sealing assembly; 211-first connecting part; 212-second connecting part; 221-piston; 222-connecting sleeve; 223-sealing sleeve; 510-first flow channel; 520-second flow channel;

[0042] 221-1-connecting part; 221-2-main body; 223-1-end ring; 223-2-protective bowl; 223-3-rubber tube. DETAILED DESCRIPTION

[0043] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0044] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0045] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0046] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, or the positions or positional relationships in which the product of the invention is usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0047] In addition, the terms "horizontal", "vertical", "overhanging" and the like do not mean that the components are required to be absolutely horizontal or overhanging, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0048] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" 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 it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0049] Some embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0050] The cementing tools used to protect reservoirs in the prior art are only applicable to reservoirs of a specific length due to their structural limitations, and therefore have technical problems of poor applicability and high use cost.

[0051] In view of this, the present invention provides a reservoir protection cementing tool, which is arranged in a wellbore and forms a first annulus with the wellbore, such as Figure 1 , Figure 2 As shown, the tool includes a tube set 100 and two main bodies 200 detachably connected to both ends of the tube set 100;

[0052] The tube assembly 100 includes an outer tube 110 and an inner tube 120 , wherein the outer tube 110 is sleeved on the inner tube 120 ;

[0053] The main body 200 includes a connecting sleeve 210 and a packing assembly 220;

[0054] The connecting sleeve 210 is sleeved on the end of the inner tube 120, and the end is connected to the outer tube 110. An annular circulation channel is formed between the connecting sleeve 210, the outer tube 110 and the inner tube 120, and a circulation hole 300 connecting the first annulus and the circulation channel is opened on the connecting sleeve 210;

[0055] The isolation assembly 220 is disposed inside the circulation hole 300 connected to the sleeve 210. The isolation assembly 220 expands toward the wellbore in an excited state to achieve flow cutoff.

[0056] When working, the cementing tool moves to the position corresponding to the reservoir position, and starts the sealing components at both ends to seal the first annulus between the cementing tool and the reservoir. When mud flows out from one end of the channel inside the cementing tool to the first annulus for cementing, under the action of the sealing component, the overflowed mud can only enter the circulation channel and return to the first annulus outside the other end of the cementing tool to continue cementing, thereby achieving the effect of bypassing the reservoir.

[0057] Since the isolation assembly 220 is arranged on the connecting sleeve 210, when the length of the reservoir to be protected does not match the preset length of the cementing tool, there is no need to re-produce the entire cementing tool. Instead, the main body 200 only needs to be mounted on a pipe group 100 of other lengths to change the length of the reservoir that can be protected by the cementing tool, thereby effectively improving the applicability of the cementing tool and reducing the cost of use.

[0058] Furthermore, if Figure 4 As shown, a swirl generator 1000 is arranged on the outer wall of the inner tube 120. The swirl generator 1000 is arranged as a spiral structure for guiding flow to prevent the circulation channel from being blocked.

[0059] In the optional scheme of this embodiment, it is more preferred that the flow area of ​​the circulation hole 300 is equivalent to the circulation area of ​​the circulation channel, and the axis is arranged perpendicular to the axis of the circulation channel to further prevent the circulation channel from being blocked.

[0060] The specific shape or structure of the connecting sleeve 210 is described in detail as follows:

[0061] like Figure 2 As shown, the connecting sleeve 210 includes a first connecting portion 211 and a second connecting portion 212 which are connected and integrally arranged; the first connecting portion 211 is sleeved on the end of the inner tube 120 and communicated with the inner tube 120 .

[0062] In the optional solution of this embodiment, it is more preferred that a sealing ring is provided at the connection between the first connecting portion 211 and the inner tube 120 to ensure sealing.

[0063] One end of the second connection part 212 abuts against the first connection part 211 , and the other end abuts against the outer tube 110 to form a continuous tube wall. A circulation channel is formed between the continuous tube wall and the inner tube 120 for the upwardly returning mud to flow.

[0064] Further, a boss is provided in the area near the circulation hole 300 of the second connection part 212, and the second connection part 212 is connected to the outer tube 110 through a coupling 400, and a receiving space for receiving the packing assembly 220 is formed between the boss and the coupling 400. It should be noted that the coupling 400 is sleeved on the second connection part 212 and the outer tube 110 and is threadedly connected thereto.

[0065] Furthermore, a flow channel hole is provided on the side of the boss near the sealing assembly 220, and the flow channel hole is connected to the first hydraulic channel. The first hydraulic channel 500 includes a first flow channel 510 and a second flow channel 520 that are connected to each other. The first flow channel 510 is provided inside the first connecting part 211, the inlet is provided on the inner wall of the first connecting part 211, and is connected to the channel in the inner tube 120, and the outlet is provided on the inner side end surface of the first connecting part 211; the second flow channel 520 is provided inside the second connecting part 212, the inlet is connected to the outlet of the first flow channel 510, and the outlet is connected to the flow channel hole.

[0066] Specifically, when it is necessary to activate the isolation assembly 220 to isolate the reservoir, the mud in the channel of the inner tube 120 is squeezed to squeeze the mud into the first flow channel 510. After that, the mud flows through the first flow channel 510 to the outlet of the second flow channel 520, and transmits pressure to squeeze the isolation assembly 220. When the hydraulic pressure of the mud reaches a certain value, the isolation assembly 220 is stimulated to expand in the direction of the wellbore to cut off the flow, so as to achieve the isolation of the first annulus corresponding to the reservoir.

[0067] The specific shape and structure of the packing assembly 220 are described in detail as follows:

[0068] like Figure 2 As shown, the packing assembly 220 includes a piston 221, a connecting sleeve 222 and a packing sleeve 223;

[0069] The connecting portion 221-1 of the piston 221 is arranged on the upper surface of the boss, the main body 221-2 is located on the side of the boss, and the piston 221 can slide along the axial direction; wherein, the connecting portion 221-1 of the piston 221 is connected to the boss through the shear pin 900. In the state without external force, the end face of the main body 221-2 of the piston 221 is attached to the side of the boss, that is, the flow channel hole is blocked at this time; when mud squeezes the main body 221-2 in the second flow channel 520 and causes the shear pin 900 to break, the piston 221 moves to the side away from the boss, and in the process of movement, in the direction of the boss approaching the piston 221, a third flow channel connected to the flow channel hole is formed between the connecting portion 221-1, the main body 221-2, and the second connecting portion 212, so as to ensure that the mud always squeezes the main body 221-2 and does not flow out to the first annulus.

[0070] One end of the connecting sleeve 222 is sleeved on the main body 221 - 2 of the piston 221 and is threadedly connected thereto, and the other end is connected to the sealing sleeve 223 ;

[0071] The packing sleeve 223 includes an end ring 223-1, a protective bowl 223-2 and a rubber tube 223-3. The wrist guards are connected to both ends of the rubber tube 223-3 and are integrally formed with the rubber tube 223-3. The end rings 223-1 are respectively connected to one end of the two wrist guards away from the rubber tube 223-3, and one of the end rings 223-1 is fixedly connected to the connecting sleeve 222, and the other end ring 223-1 is in contact with the coupling 400. When the piston 221 moves, the packing sleeve 223 is squeezed by the piston 221 through the connecting sleeve 222, so that the rubber tube 223-3 expands outward.

[0072] Furthermore, if Figure 3 As shown, a sawtooth stop ring 600 is embedded in the inner surface of the connecting sleeve 222, and a sawtooth structure 700 matching the sawtooth stop ring 600 is provided on the second connecting portion 212 to prevent the piston 221 and the connecting sleeve 222 from resetting.

[0073] Furthermore, a limiting ring 800 is mounted on the side of the serrated structure 700 on the second connecting portion 212 away from the serrated stop ring 600, and a groove cooperating with the limiting ring 800 is provided on the side of the serrated stop ring 600 on the connecting sleeve 222 close to the serrated structure 700. The limiting ring 800 and the groove cooperate to limit the maximum moving stroke of the connecting sleeve 222, thereby preventing the sealing sleeve 223 from being damaged due to excessive expansion.

[0074] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A reservoir protection cementing tool, arranged in a wellbore and forming a first annulus with the wellbore, characterized in that: include: A tube group (100) and two main bodies (200) detachably connected to two ends of the tube group (100); The tube assembly (100) comprises an outer tube (110) and an inner tube (120), wherein the outer tube (110) is sleeved on the inner tube (120); The main body (200) comprises a connecting sleeve (210) and a packing assembly (220); The connecting sleeve (210) is sleeved on the end of the inner tube (120), and the end is connected to the outer tube (110); an annular circulation channel is formed between the connecting sleeve (210), the outer tube (110) and the inner tube (120); and a circulation hole (300) is provided on the connecting sleeve (210) for connecting the first annular space and the circulation channel; The isolation assembly (220) is arranged on the inner side of the circulation hole (300) of the connecting sleeve (210), and the isolation assembly (220) expands in the direction of the wellbore in an activated state to achieve flow cutoff; The connecting sleeve (210) comprises a first connecting portion (211) and a second connecting portion (212) which are connected to each other; The first connecting portion (211) is sleeved on the end of the inner tube (120) and is in communication with the inner tube (120); One end of the second connecting portion (212) abuts against the first connecting portion (211), and the other end abuts against the outer tube (110) to form a continuous tube wall, and the circulation channel is formed between the continuous tube wall and the inner tube (120); A boss is provided in an area of ​​the second connecting portion (212) near the circulation hole (300); The second connecting portion (212) is connected to the outer tube (110) via a coupling (400), and an accommodation space for accommodating the packing assembly (220) is formed between the boss and the coupling (400); A flow channel hole is provided on the side of the boss close to the packing assembly (220), and the flow channel hole is in communication with the first hydraulic channel (500); The first hydraulic channel (500) comprises a first flow channel (510) and a second flow channel (520) which are interconnected; The first flow channel (510) is arranged inside the first connecting portion (211), the inlet is arranged on the inner wall of the first connecting portion (211), and the outlet is arranged on the inner end surface of the first connecting portion (211); The second flow channel (520) is arranged inside the second connection portion (212), the inlet of the second flow channel (520) is connected to the outlet of the first flow channel (510), and the outlet is connected to the flow channel hole.

2. The reservoir protection cementing tool according to claim 1, characterized in that: The sealing assembly (220) comprises a piston (221), a connecting sleeve (222) and a sealing sleeve (223); The connecting portion (221-1) of the piston (221) is arranged on the upper surface of the boss, the main body (221-2) is located on the side of the boss, and the piston (221) is capable of sliding along the axial direction; One end of the connecting sleeve (222) is connected to the piston (221), and the other end is connected to the sealing sleeve (223); The end of the sealing sleeve (223) facing away from the connecting sleeve (222) abuts against the coupling (400).

3. The reservoir protection cementing tool according to claim 2, characterized in that: The connecting portion (221-1) is connected to the boss via a shear pin (900).

4. The reservoir protection cementing tool according to claim 2, characterized in that: A sawtooth stop ring (600) is embedded in the inner surface of the connecting sleeve (222), and a sawtooth structure (700) matching the sawtooth stop ring (600) is provided on the second connecting portion (212).

5. The reservoir protection cementing tool according to claim 4, characterized in that: A limiting ring (800) is sleeved on the side of the sawtooth structure (700) on the second connecting portion (212) away from the sawtooth stop ring (600), and a groove cooperating with the limit ring (800) is provided on the side of the sawtooth stop ring (600) on the connecting sleeve (222) close to the sawtooth structure (700).

6. The reservoir protection cementing tool according to claim 1, characterized in that: A swirl generator (1000) is provided on the outer wall of the inner tube (120), and the swirl generator (1000) is configured as a spiral structure.

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