Drillable rubber plug and well cementation self-locking tool

Abstract

The invention relates to a drillable rubber plug and a well cementation self-locking tool. The rubber plug comprises a rubber plug rod, a first connecting part and a second connecting part, wherein the rubber plug rod is made of aluminum alloy, and the first connecting part and the second connecting part are of hollow cylindrical structures. The leather cup is constructed to be capable of being embedded with the first connecting part to form mutual axial limiting; and the guide head is made of an aluminum alloy material and is connected with the second connecting part. The first connecting part and the second connecting part form the hollow structure, so that on one hand, the difficulty of removing the rubber plug is reduced, and the rubber plug is convenient to drill and grind; on the other hand, the overall mass of the rubber plug is reduced. In addition, the leather cup and the rubber plug rod are connected in a mutual embedding mode, the contact area of the leather cup and the rubber plug rod is increased, and the connection strength is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of cementing oil and gas wells, and particularly relates to a drillable rubber plug and a cementing self-locking tool. BACKGROUND

[0002] With the development of oil and gas exploration into unconventional gas (tight gas, shale gas, coalbed methane), the object to be faced is more and more complex, and the construction period is longer and longer.

[0003] After conventional well construction is completed, the oil layer casing needs to be lowered for cementing operation, and then the oil layer casing needs to be lowered for perforation, transformation and gas production operations. This well construction method has long cycle and high cost. The integrated well construction technology can effectively overcome the above problems, greatly reduce the well construction cost and improve the development efficiency of oil and gas fields.

[0004] In integrated well construction, an outer pipe can be used for cementing. In the existing outer pipe cementing, a rubber plug is often used for displacement operation. Once a cementing failure occurs during cementing construction, the rubber plug may need to be removed to facilitate the pipe string to enter the lower part of the working barrel to carry out workover operation. SUMMARY

[0005] Based on the above problems in the prior art, the present application provides a drillable rubber plug which can be easily removed when a cementing failure occurs.

[0006] In a first aspect of the present application, a drillable rubber plug is provided, comprising a rubber plug rod of aluminum alloy material, a first connecting part and a second connecting part having a hollow cylindrical structure; and a leather cup configured to be mutually axially limited with the first connecting part; and a guide head of aluminum alloy material connected with the second connecting part.

[0007] Further, a base, a filling part filled in the cavity of the first connecting part, and an outer peripheral part wrapped outside the first connecting part are included,

[0008] Wherein, the filling part and the outer peripheral part are integrally extended from the base.

[0009] Further, an outer wall of the outer peripheral part of the leather cup is provided with a clamping groove, and an outer wall of the first connecting part is provided with a clamping part matched with the clamping groove.

[0010] Further, an outer wall of the outer peripheral part of the leather cup is provided with a mud scraping part.

[0011] Further, the guide head includes a mounting part inserted into the second connecting part and a guide part located outside the second connecting part, and an outer diameter of the mounting part is smaller than an outer diameter of the guide part.

[0012] Further, a through hole is formed in the guide head and penetrates the guide head, and an axis of the through hole is collinear with an axis of the second connecting part.

[0013] Further, the guide part is sequentially configured as a straight cylinder segment, a first inclined cylinder segment and a second inclined cylinder segment in a direction away from the mounting part, and in the direction, an outer diameter of the first inclined cylinder segment gradually increases, and an outer diameter of the second inclined cylinder segment gradually decreases.

[0014] Further, the straight cylinder segment and the first inclined cylinder segment are externally provided with a fixing part, and an inner wall of the fixing part is configured as a straight line segment capable of contacting an outer wall of the straight cylinder segment and an inclined line segment capable of abutting against an outer wall of the first inclined cylinder segment.

[0015] Further, the fixing part is in a ring type structure or a C type structure, and a first ratchet is arranged on an outer wall of the fixing part.

[0016] In a second aspect of the present application, a cementing self-locking tool is provided, which comprises the rubber plug of any one of the above, a working cylinder in communication and arranged on an outer cylinder, and a valve core arranged in an inner cavity of the working cylinder, wherein when the rubber plug is put into the inner cavity of the outer cylinder, the fixing part can cooperate with the valve core to form one-way axial positioning of the rubber plug.

[0017] The present application provides a drillable rubber plug, which comprises a rubber plug rod made of aluminum alloy, a first connecting part and a second connecting part in a hollow cylinder structure, a leather cup capable of being mutually embedded with the first connecting part to form mutual axial positioning, and a guide head made of aluminum alloy and connected with the second connecting part. By configuring the first connecting part and the second connecting part as a hollow structure, on one hand, the difficulty of removing the rubber plug is reduced, and the rubber plug is convenient to drill and grind; on the other hand, the overall quality of the rubber plug is also reduced. In addition, the leather cup and the rubber plug rod are connected in the form of mutual embedding, the contact area of the leather cup and the rubber plug rod is increased, and the connection strength is improved. BRIEF DESCRIPTION OF DRAWINGS

[0018] The present application will be further described below in combination with the drawings and examples.

[0019] Figure 1 Fig. 1 shows a structure sectional view of a rubber plug.

[0020] Figure 2 Fig. 2 shows a structure sectional view of a rubber plug. Figure 1 Fig. 3 shows a partial enlarged view of a rubber plug.

[0021] Figure 3 Fig. 4 shows a structure sectional view of an outer cylinder.

[0022] Wherein, the reference numerals in the figures: 10, rubber plug; 11, rubber plug rod; 111, first connecting part; 112, second connecting part; 113, clamping part; 114, groove; 12, skin bowl; 121, mud scraping part; 122, clamping groove; 123, filling part; 124, base; 125, outer peripheral part; 13, guide head; 131, through hole; 132, mounting part; 133, guide part; 134, straight cylinder segment; 135, first inclined cylinder segment; 136, second inclined cylinder segment; 14, fixing member; 141, first ratchet; 142, straight line segment; 143, inclined line segment;

[0023] 20, outer cylinder; 21, working cylinder; 22, valve core; 221, second ratchet; 222, sealing ring. DETAILED DESCRIPTION

[0024] In order to make the technical problems to be solved by the present application, technical solutions and beneficial effects clearer, the present application will be described in detail with reference to the drawings. The figure is a simplified schematic diagram, which only schematically illustrates the basic structure of the present application, and therefore only shows the structures related to the present application. Obviously, the described embodiments are part of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0025] REFERENCE Figure 1 and Figure 3 As shown in the figure, the present application provides a drillable well cementing self-locking tool, which comprises an outer cylinder 20, a valve core 22 arranged at a working cylinder 21 of the outer cylinder 20, and a rubber plug 10 for connecting with the valve core 22. After the well cementing cement slurry grouting is completed, the rubber plug 10 is lowered into the outer cylinder 20. The rubber plug 10 moves along the axial direction of the outer cylinder 20 to the working cylinder 21, so that the rubber plug 10 is connected with the valve core 22, thereby effectively avoiding the backflow of the cement slurry and improving the well cementing quality.

[0026] In combination with Figure 1 As shown in the figure, in some embodiments, the rubber plug 10 comprises a rubber plug rod 11, a skin bowl 12 arranged at the upper end of the rubber plug rod 11, and a guide head 13 arranged at the lower end of the rubber plug rod 11. The rubber plug rod 11, the skin bowl 12 and the guide head 13 adopt a split structure. In other embodiments, the rubber plug rod 11, the skin bowl 12 and the guide head 13 can also adopt an integrated structure, or two of them adopt an integrated structure.

[0027] In some embodiments, the upper end of the rubber stopper rod 11 is provided with a first connecting portion 111 for connecting with the cup 12. The first connecting portion 111 is generally a hollow cylindrical structure with one open end, and a snap-fit ​​portion 113 for connecting with the cup 12 protrudes from the outer wall of the first connecting portion 111. The lower end of the rubber stopper rod 11 is provided with a second connecting portion 112 for connecting with the guide head 13. The second connecting portion 112 is also generally a hollow cylindrical structure with one open end, so that one end of the guide head 13 can be inserted into the second connecting portion 112. The second connecting portion 112 and the guide head 13 can be connected by snap-fit, screw, or bolt. In this embodiment, the guide head 13 has a through hole 131, and the axis of the through hole 131 is collinear with the axis of the rubber stopper rod 11, thereby facilitating the connection of the guide head 13 and the second connecting portion 112 of the rubber stopper rod 11 by bolting.

[0028] Since both the first connecting part 111 and the second connecting part 112 are hollow cylindrical structures with one end open, it is easy to drill and grind the rubber plug rod 11 with a screw, which facilitates subsequent well repair operations.

[0029] In some embodiments, a groove 114 for installing a sealing ring is also provided on the outer wall of the rubber stopper rod 11.

[0030] Recombined Figure 1 As shown, in some embodiments, the cup 12 is generally a hollow cylindrical structure with an opening at one end facing the stopper rod 11. The cup 12 includes a base 124 and an outer peripheral portion 125 extending from the base 124 toward the first connecting portion. The outer peripheral portion 125 can cover the first connecting portion 111. The outer wall of the outer peripheral portion 125 of the cup 12 is provided with a scraping part 121. The edge of the scraping part 121 can abut against the inner wall of the working cylinder 21, thereby scraping off the cement slurry adhering to the inner wall of the working cylinder 21. The inner wall of the outer peripheral portion 125 of the cup 12 is provided with a snap-fit ​​groove 122 corresponding to the snap-fit ​​portion 113. Through the snap-fit ​​engagement of the snap-fit ​​portion 113 and the snap-fit ​​groove 122, the cup 12 is connected to the first connecting portion 111 of the stopper rod 11.

[0031] A filling portion 123 extending from the base 124 to the bottom of the first connecting portion 111 is provided in the inner cavity of the outer periphery 125 of the cup 12. By providing the filling portion 123 in the cup 12, the cup 12 and the rubber plug rod 11 form an interlocking structure. On the one hand, this increases the contact area between the first connecting portion 111 and the cup 12, improving the connection strength between the cup 12 and the rubber plug rod 11. On the other hand, it also reduces the overall weight of the rubber plug 10, thereby reducing wear on the cup 12 during the installation of the rubber plug 10, enhancing the scraping efficiency of the cup 12, and improving the cementing quality.

[0032] In some embodiments, the cup 12 can be made of nitrile rubber, fluororubber, natural rubber, etc., to ensure the wear resistance and temperature resistance of the cup 12. In actual use, the proportions of the components of the cup 12 can also be appropriately adjusted according to actual needs to meet the requirements.

[0033] In some other embodiments not shown, a snap-fit ​​portion 113 is also provided on the inner wall of the first connecting portion 111. Correspondingly, a snap-fit ​​groove 122 is provided on the side wall of the filling portion 123 to further increase the connection strength between the cup 12 and the rubber stopper rod 11. It is understood that the snap-fit ​​portion 113 and the snap-fit ​​groove 122 are not limited to being provided on the first connecting portion 111 or the cup 12. As long as the first connecting portion 111 and the cup 12 can achieve mutual axial positioning while being interlocked, it is acceptable.

[0034] refer to Figure 1 and Figure 2 As shown, in some embodiments, the guide head 13 includes a mounting portion 132 inserted into the second connecting portion 112 and a guide portion 133 located outside the second connecting portion 112. A through hole 131 extends through the guide head 13 along the axial direction of the mounting portion 132 and the guide portion 133. The outer diameter of the mounting portion 132 is smaller than the outer diameter of the guide portion 133, thereby forming an end face between the mounting portion 132 and the guide portion 133 that can abut against the end of the second connecting portion 112.

[0035] Combination Figure 2 As shown, the guide section 133 has a straight cylindrical section 134 on the side near the mounting section 132, and a first inclined cylindrical section 135 on the side away from the mounting section 132. The side of the first inclined cylindrical section 135 away from the straight cylindrical section 134 is a second inclined cylindrical section 136, and the outer walls of the first inclined cylindrical section 135 and the second inclined cylindrical section 136 form an arc-shaped transition. In the direction from the straight cylindrical section 134 to the second inclined cylindrical section 136, the outer diameter of the first inclined cylindrical section 135 gradually increases, and the outer diameter of the second inclined cylindrical section 136 gradually decreases. The first inclined cylindrical section 135 and the second inclined cylindrical section 136 streamline the guide section 133, facilitating the insertion of the rubber stopper 10 into the outer cylinder 20.

[0036] The outer peripheral sidewalls of the straight section 134 and the first inclined section 135 of the guide section 133 are equipped with a fixing member 14 that can connect the rubber plug 10 to the working cylinder 21. The fixing member 14 can form a one-way axial limit with the valve core 22.

[0037] Recombined Figure 2As shown, in some embodiments, the outer wall of the fixing member 14 is provided with a first ratchet 141, which is directed away from the guide head 13. The inner wall of the fixing member 14 includes a straight line segment 142 in contact with the first straight cylinder segment 134 and a slanted line segment 143 in cooperation with the first slanted cylinder segment 135. When the rubber plug 10 is installed at the working cylinder 21, the one-way axial limit is formed between the first ratchet 141 and the valve core 22. The cement slurry in the outer cylinder 20 acts on the guide head 13, so that the rubber plug 10 has a tendency to move upward. At this time, the slanted line segment 143 of the fixing member 14 is in abutment with the outer wall of the first slanted cylinder segment 135. The end of the fixing member 14 close to the second connecting portion 112 can be in abutment with the end of the second connecting portion 112, so as to avoid the axial sliding of the fixing member 14 along the rubber plug 10 due to the contact with the outer cylinder 20 during the installation of the rubber plug 10.

[0038] In some embodiments, the fixing member 14 can be in a ring structure or a C-shaped structure. Since the rubber plug rod 11 and the guide head 13 are in a split structure, the fixing member 14 can be conveniently installed on the guide head 13.

[0039] Reference Figure 3 As shown, in some embodiments, the valve core 22 is generally in a hollow tubular structure with both ends open, and the inner wall of the valve core 22 is provided with a second ratchet 221 in cooperation with the first ratchet 141. Through the clamping cooperation of the first ratchet 141 and the second ratchet 221, the one-way axial limit of the rubber plug 10 is formed, so as to avoid the upward movement of the rubber plug rod 11 under the action of the cement slurry in the outer cylinder 20.

[0040] In some embodiments, the outer wall of the valve core 22 and the inner wall of the working cylinder 21 are further provided with a sealing ring 222, so as to increase the sealing property between the valve core 22 and the working cylinder 21 and avoid the leakage of the cement slurry.

[0041] In some embodiments, the materials of the rubber plug rod 11, the guide head 13 and the valve core 22 are all selected to be aluminum alloy, so that the rubber plug 10 can be easily drilled and ground by the screw rod on the rubber plug rod 11 on the basis of satisfying the positive and reverse pressure bearing of 50 MPa, and the subsequent well repair operation is facilitated.

[0042] The drillable rubber plug has the beneficial effects that the rubber plug rod 11 is made of aluminum alloy material, the first connecting part 111 and the second connecting part 112 have hollow cylindrical structures, the rubber bowl 12 is configured to be capable of being embedded with the first connecting part 111, and the guide head 13 made of aluminum alloy material is connected with the second connecting part 112.

[0043] In the description of the present application, it should be noted that, unless otherwise explicitly defined and limited, the terms "mounting", "connecting", "connecting" should be understood in a broad sense, for example, it can be fixed connection, can also be detachable connection or integral connection, can be mechanical connection, can be direct connection or indirect connection through intermediate medium, can be internal communication of two elements or interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0044] It should be understood that the terms "length", "width", "upper", "lower", "front and back", "left and right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only used to facilitate the description of the present application and simplify the description, and are not intended to indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0045] The above is based on the ideal embodiment of the present application, and through the above description, relevant personnel can make various changes and modifications without deviating from the scope of the present application. The technical scope of the present application is not limited to the contents of the specification, and must be determined according to the scope of the claims.

Claims

1. A drillable rubber stopper, characterized in that, include The aluminum alloy rubber stopper rod (11) has a first connecting part (111) and a second connecting part (112) with a hollow cylindrical structure; and A leather cup (12), the leather cup (12) being configured to interlock with the first connecting portion (111) to form mutual axial positioning; and A guide head (13) made of aluminum alloy is connected to the second connecting part (112).

2. The drillable rubber stopper according to claim 1, characterized in that, The leather cup (12) includes a base (124), a filling portion (123) filling the cavity of the first connecting portion (111), and an outer peripheral portion (125) covering the first connecting portion (111). The filling portion (123) and the outer peripheral portion (125) both extend integrally from the base portion (124).

3. The drillable rubber stopper according to claim 2, characterized in that, The inner wall of the outer periphery (125) of the leather cup (12) is provided with a snap-fit ​​groove (122), and the outer wall of the first connecting part (111) is provided with a snap-fit ​​part (113) that snaps into the snap-fit ​​groove (122).

4. The drillable rubber stopper according to claim 3, characterized in that, The outer wall of the outer periphery (125) of the leather bowl (12) is provided with a mud scraping part (121).

5. The drillable rubber stopper according to claim 1, characterized in that, The guide head (13) includes a mounting part (132) inserted into the second connecting part (112) and a guide part (133) located outside the second connecting part (112), wherein the outer diameter of the mounting part (132) is smaller than the outer diameter of the guide part (133).

6. The drillable rubber stopper according to claim 5, characterized in that, The guide head (13) has a through hole (131) that passes through the guide head (13), and the axis of the through hole (131) is collinear with the axis of the second connecting part (112).

7. The drillable rubber stopper according to claim 6, characterized in that, The guide section (133) is constructed in sequence as a straight section (134), a first inclined section (135), and a second inclined section (136) in the direction away from the mounting section (132); and in the direction thereof, the outer diameter of the first inclined section (135) gradually increases, and the outer diameter of the second inclined section (136) gradually decreases.

8. The drillable rubber stopper according to claim 7, characterized in that, A fastener (14) is installed on the outside of the straight section (134) and the first inclined section (135). The inner wall of the fastener (14) is constructed as a straight section (142) that can contact the outer wall of the straight section (134) and an inclined section (143) that can abut against the outer wall of the first inclined section (135).

9. The drillable rubber stopper according to claim 8, characterized in that, The fastener (14) is a ring-shaped structure or a C-shaped structure, and a first ratchet (141) is provided on the outer wall of the fastener (14).

10. A cementing self-locking tool, characterized in that, include The rubber stopper (10) as described in any one of claims 1 to 9, A working cylinder (21) is connected to the outer cylinder (20), and a valve core (22) is provided in the inner cavity of the working cylinder (21). When the rubber plug (10) is inserted into the inner cavity of the outer cylinder (20), the fixing member (14) can cooperate with the valve core (22) to form a one-way axial limit on the rubber plug (10).

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