Spiral straightening cleaning composite rubber plug

Abstract

The present invention belongs to the technical field of oil and gas cementing tools, and particularly relates to a spiral centralizing and cleaning composite rubber plug, aiming at solving the problems in the prior art that the rubber plug cannot effectively clean the inner wall of the casing and cannot be effectively centralized, resulting in the inability to build pressure. The spiral centralizing and cleaning composite rubber plug provided in this application includes a first structural member, a second structural member, and a third structural member connected in sequence. The first structural member is provided with spiral turbulent flow strips distributed in a 360° circumference, which are used to keep the entire rubber plug in a centralized state under large inclination or horizontal conditions. The second structural member is provided with a cleaning rubber bowl and a centralizing rubber wing, which can clean the residual cement slurry on the inner wall of the pipe string and assist in centralizing. The third structural member is designed with a centralizing tail insert, which can keep the composite rubber plug centralized during the migration process. This application has strong versatility, a simple structure, is safe and reliable, and rotates and moves downward during use, reaching the bottom to cooperate with the position of the rubber plug seat to achieve bump pressure, sealing, and isolation, and complete the cementing construction.

Description

Technical Field

[0001] The invention belongs to the technical field of petroleum and natural gas cementing tools, and in particular relates to a spiral straightening and cleaning composite rubber plug. Background Art

[0002] Usually, during the cementing process, the rubber plug follows the cement slurry downward to scrape off the cement slurry adhering to the inner wall of the casing, prevent the displaced drilling fluid from mixing with the cement slurry, avoid contamination of the tail cement slurry, and ensure the quality of the bottom cement bonding. Usually, the rubber plug is made of rubber or other flexible materials compatible with the wellbore. One issue worth noting is that in highly deviated wells or long horizontal wells, the rubber of the rubber plug will mostly wear on the low side, which cannot effectively remove the residual cement slurry on the inner wall of the casing, leaving cement residues to increase the complexity of subsequent construction. At the same time, due to the wear of the rubber plug, the plug cannot be well centered, resulting in mixing of slurry and failure to collide and press, which will seriously affect the quality of the tail pipe cementing. Summary of the invention

[0003] In order to solve the above-mentioned problems in the prior art, that is, in order to solve the problem that the rubber plug cannot effectively clean the inner wall of the casing under the construction condition of large well deviation in the prior art, and cannot be effectively centered, resulting in the inability to hold pressure, the first aspect of the present application provides a spiral straightening cleaning composite rubber plug, including a first structural member, a second structural member and a third structural member connected in sequence, wherein the first structural member, the second structural member and the third structural member all include columnar structures with the same outer diameter;

[0004] A spiral turbulence strip is provided on a side wall of one end of the first structural member close to the second structural member, and the spiral turbulence strip is evenly distributed in a spiral along the circumferential direction of the columnar structure of the first structural member;

[0005] The second structural member is provided with a cleaning rubber bowl assembly and a straightening rubber wing, wherein the two straightening rubber wings are respectively arranged at the upper part and the lower part of the cleaning rubber bowl assembly, and the cleaning rubber bowl assembly comprises a plurality of cleaning rubber bowls which are sequentially plugged and arranged along the length direction of the second structural member;

[0006] A straightening tail plug is arranged at one end of the third structural member away from the second structural member, and a plurality of the straightening tail plugs are evenly distributed along the circumference of the columnar structure of the third structural member. The height of the upper surface of the straightening tail plug gradually decreases toward the end away from the third structural member.

[0007] In some preferred technical solutions, the cleaning rubber bowl is an annular cone structure, the inner diameter of the small end of the cleaning rubber bowl matches the outer edge of the columnar structure of the second structural member, and the large end of the cleaning rubber bowl extends obliquely along the direction of the third structural member to form a cleaning chamber in the middle.

[0008] In some preferred technical solutions, the small end of the cleaning rubber bowl located in the middle of the cleaning rubber bowl assembly is disposed in the cleaning chamber of the previous cleaning rubber bowl.

[0009] In some preferred technical solutions, the straightening tail plug is a right trapezoidal structure. The height of the right trapezoidal structure is flush with the bottom end of the third structural member. The first base of the right trapezoidal structure is fixed to the outer edge of the third structural member. The second base of the right trapezoidal structure is disposed away from the third structural member, and the length of the first base is greater than the length of the second base.

[0010] In some preferred technical solutions, a sealing groove is provided at one end of the first structural member facing away from the second structural member. The sealing groove is used to accommodate a sealing ring to achieve a seat seal with the rubber plug seat.

[0011] The second aspect of the present application provides a spiral straightening and cleaning composite rubber plug, including a first structural member, a second structural member, and a third structural member. There are a plurality of the second structural members. The first structural member, the plurality of second structural members, and the third structural member are sequentially connected. The first structural member, the second structural member, and the third structural member are all columnar structures with the same outer diameter;

[0012] A spiral turbulence strip is provided on the side wall of one end of the first structural member close to the second structural member. The spiral turbulence strips are spirally and evenly distributed along the circumferential direction of the columnar structure of the first structural member;

[0013] The second structural member is provided with a cleaning rubber bowl assembly and straightening rubber wings. The two straightening rubber wings are respectively disposed on the upper and lower parts of the cleaning rubber bowl assembly. The cleaning rubber bowl assembly includes a plurality of cleaning rubber bowls sequentially inserted along the length direction of the second structural member;

[0014] A straightening tail plug is provided at one end of the third structural member facing away from the second structural member. A plurality of the straightening tail plugs are evenly distributed along the circumferential direction of the columnar structure of the third structural member. The height of the upper surface of the straightening tail plug gradually decreases towards the end away from the third structural member.

[0015] In some preferred technical solutions, the cleaning rubber bowl is a ring-cone structure. The inner diameter of the small end of the cleaning rubber bowl matches the outer edge of the columnar structure of the second structural member. The large end of the cleaning rubber bowl extends obliquely along the direction of the third structural member to form a cleaning chamber in the middle.

[0016] In some preferred technical solutions, the small end of the cleaning rubber bowl located in the middle of the cleaning rubber bowl assembly is disposed in the cleaning chamber of the previous cleaning rubber bowl.

[0017] In some preferred technical solutions, the centralizing tail plug has a right trapezoidal structure. The height of the right trapezoidal structure is flush with the bottom end of the third structural member. The first base of the right trapezoidal structure is fixed to the outer edge of the third structural member. The second base of the right trapezoidal structure is arranged away from the third structural member, and the length of the first base is greater than that of the second base.

[0018] In some preferred technical solutions, a sealing groove is provided at one end of the first structural member facing away from the second structural member. The sealing groove is used to accommodate a sealing ring to achieve seat sealing with the rubber plug seat.

[0019] Advantages of the present invention:

[0020] The spiral centralizing and cleaning composite rubber plug of the present invention rotates and migrates in the pipe string. Spiral turbulence strips are provided on the first structural member and are circumferentially distributed at 360°. Its elastic spiral structure design can play a good centralizing role, keeping the entire rubber plug in a centered state in a large inclination or horizontal state. The design of the spiral turbulence strips can not only clean the residual cement slurry on the inner wall of the pipe string but also enable the rubber plug to move downward in a spiral rotation state. In addition, a cleaning rubber bowl and centralizing rubber wings are designed on the second structural member, which can clean the residual cement slurry on the inner wall of the pipe string and assist in centering. A centralizing tail plug is designed on the third structural member, which can keep the composite rubber plug centered during migration. After the cement slurry is displaced, this tool is sent in, and drilling fluid is continuously injected into the well. The tool moves downward and reaches the bottom to cooperate with the position of the rubber plug seat to achieve bump pressure, sealing, and isolation, completing the cementing construction. This tool has strong versatility, a simple structure, is safe and reliable, and can well clean the residual cement slurry in the pipe string. Due to the design of its spiral turbulence strips and centralizing tail plug, it can ensure that the tool plays a good centralizing role in the large inclination well or horizontal well section. The design of the cleaning rubber bowl and centralizing rubber wings can effectively remove the residual cement slurry on the inner wall of the casing, reduce complexity for the next construction step, and at the same time can effectively center to achieve good sealing performance. Description of the Drawings

[0021] By reading the detailed description of the non-restrictive embodiments with reference to the following drawings, other features, objectives, and advantages of the present application will become more obvious:

[0022] Figure 1 It is a schematic diagram of the overall structure of the spiral centralizing and cleaning composite rubber plug according to an embodiment of the present invention;

[0023] Figure 2 It is a cross-sectional view of the spiral centralizing and cleaning composite rubber plug according to an embodiment of the present invention;

[0024] List of reference numerals:

[0025] 1-first structural member; 2-spiral turbulence strip; 3-righting rubber wing; 4-cleaning rubber bowl; 5-second structural member; 6-third structural member; 7-righting tail plug; 8-sealing groove. DETAILED DESCRIPTION

[0026] In order to make the embodiments, technical solutions and advantages of the present invention more obvious, the technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the embodiments described are part of the embodiments of the present invention, rather than all the embodiments. It should be understood by those skilled in the art that these implementation modes are only used to explain the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0027] A spiral straightening cleaning composite rubber plug of the present invention comprises a first structural member, a second structural member and a third structural member, wherein the first structural member, the second structural member and the third structural member all comprise columnar structures with the same outer diameter; wherein the second structural member may be one or more, when the second structural member is one, the first structural member, the second structural member and the third structural member are connected in sequence, and when the second structural member is multiple, the first structural member, multiple second structural members and the third structural member are connected in sequence;

[0028] A spiral turbulence strip is arranged on the side wall of one end of the first structural member close to the second structural member, and the spiral turbulence strip is evenly distributed in a spiral along the circumferential direction of the columnar structure of the first structural member;

[0029] The second structural member is provided with a cleaning rubber bowl assembly and a straightening rubber wing, the two straightening rubber wings are respectively arranged at the upper part and the lower part of the cleaning rubber bowl assembly, and the cleaning rubber bowl assembly includes a plurality of cleaning rubber bowls which are sequentially plugged and arranged along the length direction of the second structural member;

[0030] A stabilizing tail plug is arranged at one end of the third structural member away from the second structural member, and a plurality of stabilizing tail plugs are evenly distributed along the circumference of the columnar structure of the third structural member.

[0031] In order to more clearly illustrate the spiral straightening and cleaning composite rubber plug of the present invention, a preferred embodiment of the present invention will be described in detail below in conjunction with the accompanying drawings.

[0032] Embodiment 1:

[0033] As a preferred embodiment of the present invention, the spiral straightening cleaning composite rubber plug of the present invention is as follows Figure 1 As shown, it includes a first structural member 1, a second structural member 5 and a third structural member 6. Preferably, the first structural member 1, the second structural member 5 and the third structural member 6 are connected by threads.

[0034] Among them, the first structural member 1, the second structural member 5 and the third structural member 6 all include columnar structures with the same outer diameter. A spiral turbulence strip 2 is arranged on the side wall of one end of the first structural member 1 close to the second structural member 5, and the spiral turbulence strip 2 is evenly distributed in a spiral along the circumferential direction of the columnar structure of the first structural member; specifically, the highly elastic spiral structure design of the spiral turbulence strip 2 can play a good straightening role, keeping the entire rubber plug in a centered state at a large inclination or in a horizontal state. The spiral turbulence strip design can not only clean the residual cement slurry on the inner wall of the pipe string, but also make the rubber plug move in a spiral rotation and downward state.

[0035] More preferably, the present application comprises a plurality of 360° spiral turbulence strips, and the plurality of spiral turbulence strips are arranged at certain circumferential intervals.

[0036] In addition, a sealing groove 8 is provided at one end of the first structural member 1 away from the second structural member 5, and the sealing groove 8 is used to accommodate a sealing ring to achieve sealing with the plug seat. Preferably, the present application is provided with two sealing grooves 8, which are arranged at intervals, and the sealing member can be installed to achieve sealing with the plug seat, and is used as a drop-in cementing plug, which is designed with a ball seat or a plug seat for matching application.

[0037] The second structural member is provided with a cleaning rubber bowl assembly and a righting rubber wing 3, and the two righting rubber wings 3 are respectively arranged at the upper and lower parts of the cleaning rubber bowl assembly; more preferably, the righting rubber wing 3 is a disc structure, and the two groups of righting rubber wings are respectively arranged at the upper and lower parts of the cleaning rubber bowl assembly, and each group of righting rubber wings includes a plurality of disc structures arranged in sequence along the length direction of the second structural member.

[0038] The cleaning rubber bowl assembly includes a plurality of cleaning rubber bowls 4 which are sequentially plugged in along the length direction of the second structural member 5; Figure 2 The cleaning rubber bowl 4 is made of elastic material, and its quantity includes but is not limited to the quantity shown in the figure. Multiple ones can be combined as needed. Its main function is to scrape off the residual cement slurry in the pipe column.

[0039] Specifically, the cleaning rubber bowl 4 is a ring cone structure, the inner diameter of the small end of the cleaning rubber bowl 4 matches the outer edge of the columnar structure of the second structural member 5, and the large end of the cleaning rubber bowl 4 extends obliquely along the direction of the third structural member 6 to form a cleaning chamber in the middle. The small end of the cleaning rubber bowl 4 located in the middle of the cleaning rubber bowl assembly is arranged in the cleaning chamber of the previous cleaning rubber bowl 4, that is, each cleaning rubber bowl in the cleaning rubber bowl assembly is plugged in and arranged in sequence.

[0040] Specifically, the straightening rubber wings 3 are arranged at both ends of the cleaning rubber bowl assembly to assist in centering, and at the same time remove harder or larger residual cement blocks during the movement process, thereby protecting the cleaning rubber bowl 4.

[0041] One end of the third structural member facing away from the second structural member is provided with a centering tail plug 7, and a plurality of centering tail plugs 7 are evenly distributed along the circumferential direction of the columnar structure of the third structural member.

[0042] The centering tail plug 7 is a right trapezoidal structure. The height of the right trapezoidal structure is flush with the bottom end of the third structural member. The first base of the right trapezoidal structure is fixed to the outer edge of the third structural member. The second base of the right trapezoidal structure is arranged away from the third structural member, and the length of the first base is greater than the length of the second base. The centering tail plug 7 of the present application can reduce the downward resistance and play a role in centering at the same time, so that the whole rubber plug is in a centered state. It can be understood that the centering tail plug 7 shown in the drawings is a preferred embodiment of the present application, and those skilled in the art can also flexibly set the structure of the centering tail plug 7, such as a wedge shape, etc. Further, the outer diameters of the outer edge of the centering tail plug 7, the outer edge of the cleaning rubber bowl 4, and the outer edge of the centering rubber wing 3 of the present application are the same.

[0043] Embodiment 2

[0044] The main difference between this embodiment and Embodiment 1 is that there are multiple second structural members 5 in this embodiment, and the multiple second structural members 5 are arranged in series in sequence. Since the spiral centering and cleaning composite rubber plug of the present application adopts a segmented structure design, the number of the second structural members 5 can be appropriately increased as needed.

[0045] Further, the other structures of this embodiment are the same as those of Embodiment 1, that is, the first structural member 1 is designed with spiral turbulence strips 2 evenly distributed in a 360° circumferential rotation, and is made of an elastic material. Generally, materials that can be used are plastics, soft metals or composite materials. The second structural member 5 is designed with a cleaning rubber bowl 4 and a centering rubber wing 3, and the number of the cleaning rubber bowls 4 is not limited to the number shown in the figure, and the corresponding number can be installed according to actual downhole needs. The third structural member 6 is designed with 4 wedge-shaped centering tail plugs 7 arranged in a uniform arrangement. The centering design of the upper spiral turbulence strip 2 and the lower wedge-shaped centering tail plug 7 can ensure the centering degree of the whole rubber plug during the migration process. The first structural member 1, the second structural member 5, and the third structural member 6 are connected by threads, and at the same time, the segmented structure can appropriately increase the number of the second structural members 5 as needed. The tail end of the first structural member 1 is designed with a chamfer, which can smoothly guide the rubber plug to the rubber plug seat. A sealing groove 8 is designed on it, and the cooperation with the sealing member can ensure the sealing performance between the rubber plug and the rubber plug seat, and achieve the effects of bump pressure and pressure holding.

[0046] It can be understood that Embodiment 2 of the present application has the same technical effects as Embodiment 1 and can solve the same technical problems.

[0047] After the cement slurry is displaced, the tool is inserted and mud is continuously injected into the well. The tool migrates downward along the wellbore. The spiral turbulence strips 2 of the first structural member 1 and the wedge-shaped centralizing tail insert 7 on the third structural member 6 maintain the centrality of the rubber plug in the wellbore. At the same time, the cleaning rubber bowl 4 and the centralizing rubber wing 3 designed on the second structural member 5 can scrape off the residual cement slurry in the pipe string and keep the wellbore clean. The first structural member 1 reaches the rubber plug seat position to achieve bump pressure sealing and isolation, completing the cementing operation.

[0048] Among the technical solutions in the embodiments of the present application described above, there are at least the following technical effects and advantages:

[0049] The spiral centralizing and cleaning composite rubber plug of the present invention rotates and migrates in the pipe string. The spiral turbulence strips are arranged on the first structural member in a 360° circular distribution. The elastic spiral structure design can play a good centralizing role, keeping the entire rubber plug in a centered state in a highly deviated or horizontal wellbore. The design of the spiral turbulence strips can not only clean the residual cement slurry on the inner wall of the pipe string but also make the rubber plug move downward in a spiral rotation state. In addition, the cleaning rubber bowl and the centralizing rubber wing are designed on the second structural member, which can clean the residual cement slurry on the inner wall of the pipe string and assist in centralizing. The centralizing tail insert is designed on the third structural member, which can keep the composite rubber plug centered during migration. After the cement slurry is displaced, the tool is sent into the well, and drilling fluid is continuously injected into the well. The tool moves downward and reaches the bottom to cooperate with the rubber plug seat position to achieve bump pressure, sealing, and isolation, completing the cementing operation. The tool has strong versatility, a simple structure, is safe and reliable, and can well clean the residual cement slurry in the pipe string. Due to the design of its spiral turbulence strips and centralizing tail insert, it can ensure that the tool plays a good centralizing role in highly deviated or horizontal well sections. The design of the cleaning rubber bowl and the centralizing rubber wing can effectively remove the residual cement slurry on the inner wall of the casing, reduce complexity for the next construction step, and at the same time can effectively centralize to achieve good sealing performance.

[0050] It should be noted that in the description of the present invention, the terms indicating directions or positional relationships such as "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. are based on the directions or positional relationships shown in the drawings. This is only for convenience of description and does not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be construed as a limitation of the present invention. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0051] In addition, it should be noted that in the description of the present invention, unless otherwise clearly defined and limited, the terms "installed", "connected", and "coupled" 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 components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0052] The term "comprising" or any other similar term is intended to cover non-exclusive inclusion, such that a process, article, or apparatus / device comprising a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to those processes, articles, or apparatus / device.

[0053] So far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the protection scope of the present invention.

Claims

1. A spiral straightening and cleaning composite rubber plug, It is characterized in that It comprises a first structural member, a second structural member and a third structural member connected in sequence, wherein the first structural member, the second structural member and the third structural member all comprise columnar structures with the same outer diameter; A spiral turbulence strip is provided on a side wall of one end of the first structural member close to the second structural member, and the spiral turbulence strip is evenly distributed in a spiral along the circumferential direction of the columnar structure of the first structural member; The second structural member is provided with a cleaning rubber bowl assembly and a straightening rubber wing, wherein the two straightening rubber wings are respectively arranged at the upper part and the lower part of the cleaning rubber bowl assembly, and the cleaning rubber bowl assembly comprises a plurality of cleaning rubber bowls which are sequentially plugged and arranged along the length direction of the second structural member; A straightening tail plug is arranged at one end of the third structural member away from the second structural member, and a plurality of the straightening tail plugs are evenly distributed along the circumference of the columnar structure of the third structural member. The height of the upper surface of the straightening tail plug gradually decreases toward the end away from the third structural member.

2. The spiral straightening and cleaning composite rubber plug according to claim 1, It is characterized in that The cleaning rubber bowl is an annular cone structure, the inner diameter of the small end of the cleaning rubber bowl matches the outer edge of the columnar structure of the second structural member, and the large end of the cleaning rubber bowl extends obliquely along the direction of the third structural member to form a cleaning chamber in the middle.

3. The spiral straightening and cleaning composite rubber plug according to claim 2, It is characterized in that The small end of the cleaning glue bowl located in the middle of the cleaning glue bowl assembly is arranged in the cleaning chamber of the previous cleaning glue bowl.

4. The spiral straightening and cleaning composite rubber plug according to claim 1, It is characterized in that The righting tail plug is a right-angled trapezoidal structure, the height of the right-angled trapezoidal structure is flush with the bottom end of the third structural member, the first bottom side of the right-angled trapezoidal structure is fixed to the outer edge of the third structural member, the second bottom side of the right-angled trapezoidal structure is arranged away from the third structural member, and the length of the first bottom side is greater than the length of the second bottom side.

5. The spiral straightening and cleaning composite rubber plug according to claim 1, It is characterized in that A sealing groove is provided at one end of the first structural member away from the second structural member, and the sealing groove is used to accommodate a sealing ring to achieve sealing with the rubber plug seat.

6. A spiral straightening and cleaning composite rubber plug, It is characterized in that It comprises a first structural member, a second structural member and a third structural member, the second structural member is a plurality, the first structural member, the plurality of the second structural members and the third structural member are connected in sequence, and the first structural member, the second structural member and the third structural member are all columnar structures with the same outer diameter; A spiral turbulence strip is provided on a side wall of one end of the first structural member close to the second structural member, and the spiral turbulence strip is evenly distributed in a spiral along the circumferential direction of the columnar structure of the first structural member; The second structural member is provided with a cleaning rubber bowl assembly and a straightening rubber wing, wherein the two straightening rubber wings are respectively arranged at the upper part and the lower part of the cleaning rubber bowl assembly, and the cleaning rubber bowl assembly comprises a plurality of cleaning rubber bowls which are sequentially plugged and arranged along the length direction of the second structural member; A straightening tail plug is arranged at one end of the third structural member away from the second structural member, and a plurality of the straightening tail plugs are evenly distributed along the circumference of the columnar structure of the third structural member. The height of the upper surface of the straightening tail plug gradually decreases toward the end away from the third structural member.

7. The spiral straightening and cleaning composite rubber plug according to claim 6, It is characterized in that The cleaning rubber bowl is an annular cone structure, the inner diameter of the small end of the cleaning rubber bowl matches the outer edge of the columnar structure of the second structural member, and the large end of the cleaning rubber bowl extends obliquely along the direction of the third structural member to form a cleaning chamber in the middle.

8. The spiral straightening and cleaning composite rubber plug according to claim 7, It is characterized in that The small end of the cleaning glue bowl located in the middle of the cleaning glue bowl assembly is arranged in the cleaning chamber of the previous cleaning glue bowl.

9. The spiral straightening and cleaning composite rubber plug according to claim 6, It is characterized in that The righting tail plug is a right-angled trapezoidal structure, the height of the right-angled trapezoidal structure is flush with the bottom end of the third structural member, the first bottom side of the right-angled trapezoidal structure is fixed to the outer edge of the third structural member, the second bottom side of the right-angled trapezoidal structure is arranged away from the third structural member, and the length of the first bottom side is greater than the length of the second bottom side.

10. The spiral straightening and cleaning composite rubber plug according to claim 6, It is characterized in that A sealing groove is provided at one end of the first structural member away from the second structural member, and the sealing groove is used to accommodate a sealing ring to achieve sealing with the rubber plug seat.

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