Cementing multi-purpose rubber plug and cementing tool and method

Abstract

The application discloses a cementing multipurpose rubber plug and a cementing tool and method. The cementing multipurpose rubber plug comprises a rubber plug body, a rubber plug rubber body, a striking sleeve, a pin, a rupture disc and a gland. The rubber plug rubber body is sleeved outside the rubber plug body. One end of the pin is inserted into the side wall of the striking sleeve, and the other end is inserted into the rubber plug body. The side wall of the striking sleeve is connected with the rubber plug body through the pin. The rubber plug body is in a cylindrical shape, and the inner cavity of the rubber plug body is provided with the striking sleeve and the rupture disc from top to bottom. The gland is threadedly connected with the rubber plug body. The cementing multipurpose rubber plug can be used in multiple stages of cementing, and can be used as a calibration rubber plug. The accuracy of the measurement of the replacement amount of the slurry can be improved, the problems of the casing plug and the replacement can be avoided, a corresponding solution can be provided for the pipe string buckling caused by the release of the rubber plug before the cement injection, and the cementing operation accidents can be avoided.

Description

Technical Field

[0001] This invention relates to the field of underground energy exploration technology for petroleum and natural gas, and particularly to a multi-purpose cementing plug, cementing tools, and methods. Background Technology

[0002] In the drilling process, in order to reinforce the wellbore, ensure continued drilling, seal off oil, gas and water layers, and ensure reasonable oil and gas production during exploration and the entire production process, the operation of running casing and filling the annulus between the wellbore and the steel pipe with cement is called cementing operation.

[0003] Cementing is an essential and indispensable part of the drilling and completion process, encompassing casing installation and cementing. Cementing technology is a comprehensive application of multiple disciplines, characterized by its systematic, one-off, and short-duration nature. The primary purpose of cementing is to protect and support the casing within oil and gas wells, and to seal off oil, gas, and water formations.

[0004] Cementing plugs serve to isolate cement slurry, clean the casing wall, and prevent cement slurry contamination. After the plug is pressed against the float collar, it can accurately indicate the position of cement slurry replacement and the casing sealing performance.

[0005] Upper and lower rubber plugs are generally used as a set. The upper rubber plug separates the upper cement slurry from the mud slurry, preventing the cement slurry from being contaminated, and at the same time displaces the cement slurry into the annulus.

[0006] Before cementing, a lower rubber plug is first inserted, and the well wall is cleaned by pumping and scraping. This serves to separate the lower cement slurry from the mud, preventing contamination of the cement slurry. After pressure is applied, because the lower rubber plug is hollow, the pressure builds up and ruptures the rubber diaphragm, providing a channel for the cement slurry and establishing circulation. Then, cement is injected, an upper rubber plug is inserted, and pumping and pressure are applied to complete the cementing process.

[0007] During cementing operations in deep and ultra-deep wells, a large amount of displacement fluid is required. Due to the issue of measurement accuracy, it is not advisable to pursue pressure during cementing, which can lead to casing blockage and emptying, thus affecting the quality of cementing.

[0008] Meanwhile, when using traditional single-plug cementing operations, accidents have occurred where operators have made mistakes by releasing the plug prematurely before cementing, causing blockage of the tubing string and making cementing operations impossible. Summary of the Invention

[0009] In view of the above problems, the present invention is proposed to provide a cementing multipurpose rubber plug and cementing tools and methods that overcome or at least partially solve the above problems.

[0010] In a first aspect, embodiments of the present invention provide a cementing multi-purpose rubber plug, comprising: a plug body, a plug rubber body, an impact sleeve, a pin, a rupture disc, and a pressure cap;

[0011] The rubber body of the rubber stopper is fitted over the rubber stopper body;

[0012] One end of the pin is inserted into the side wall of the impact sleeve, and the other end is inserted into the rubber plug body; the side wall of the impact sleeve is connected to the rubber plug body by the pin.

[0013] The rubber stopper body is cylindrical, and its inner cavity is provided with an impact sleeve and a rupture disc from top to bottom;

[0014] The gland is threadedly connected to the rubber stopper body.

[0015] In one embodiment, an impact head is provided at one end of the impact sleeve facing the rupture disc, the impact head being used to impact the edge of the rupture disc when the impact sleeve moves downward under pressure.

[0016] In one embodiment, when the cementing multipurpose plug is used as a single plug during construction and as an upper plug, the pressure rating of the pin is set to one times the cementing construction pressure.

[0017] In one embodiment, when the cementing multipurpose rubber plug is used as a double rubber plug in construction and as a lower rubber plug, the pressure rating of the pin is set to one times the cementing construction pressure.

[0018] When the cementing multipurpose rubber plug is used as a double rubber plug in construction and is used as the upper rubber plug, the pressure of the pin meets the downhole rubber plug rupture pressure requirements.

[0019] In one embodiment, when the cementing multipurpose plug is used as a calibration plug, the pressure level of the pin meets the requirements for pressure observation.

[0020] In one embodiment, the above-mentioned cementing multipurpose rubber plug further includes: a rubber pad;

[0021] The rubber pad is annular and is disposed between the rupture disc and the pressure cap.

[0022] In one embodiment, the above-mentioned cementing multipurpose rubber plug further includes: a plurality of sealing rings;

[0023] The plurality of sealing rings are arranged sequentially from top to bottom on the side wall of the rubber stopper body, respectively located at the position of the impact sleeve and the position of the rupture disc.

[0024] Secondly, embodiments of the present invention provide a cementing tool, characterized in that the cementing tool includes at least one multi-purpose cementing plug as described above.

[0025] In one embodiment, the cementing multipurpose rubber plug is a single plug, which is the upper rubber plug of the cementing tool;

[0026] The cementing multi-purpose rubber plug is in two parts, one of which is the upper rubber plug of the cementing tool, and the other is the lower rubber plug of the cementing tool.

[0027] Thirdly, embodiments of the present invention provide a method for using the aforementioned multi-purpose cementing plug, comprising:

[0028] During cementing operations, the multi-purpose cementing plug is used as the top plug;

[0029] Alternatively, during cementing operations, the multi-purpose cementing plug can be pumped as the lower plug to scrape and clean the well wall, and after cementing, the upper plug can be inserted, and then pumped and pressed until the cementing is completed.

[0030] Alternatively, it can be used as a calibration plug during cementing operations.

[0031] The beneficial effects of the above-described technical solutions provided in the embodiments of the present invention include at least the following:

[0032] This invention provides a multi-purpose cementing plug, cementing tools, and methods. The multi-purpose cementing plug includes a plug body, a rubber plug body, an impact sleeve, a pin, a rupture disc, and a pressure cap. One end of the pin is inserted into the side wall of the impact sleeve, and the other end is inserted into the plug body. The side wall of the impact sleeve is connected to the plug body via the pin. The plug body is cylindrical, and its inner cavity contains the impact sleeve and the rupture disc from top to bottom. The pressure cap is threadedly connected to the plug body. This invention provides a multi-purpose cementing plug that can be used in multiple stages of cementing operations, improving the quality of cementing operations. This multi-purpose cementing plug can be used as an upper plug in the cementing process, or simultaneously as an upper and lower plug in the cementing process. It can also be used as a calibration plug in the pre-cementing slurry displacement calibration process, improving the accuracy of slurry displacement measurement. This solves the problem of casing blockage and empty displacement caused by measurement issues during cementing operations in deep and ultra-deep wells, where the cementing process is hesitant to pursue impact pressure. It can also provide solutions for situations where cementing accidents occur, such as pre-releasing the rubber plug before cementing to prevent blockage of the tubing string, thus avoiding cementing operation accidents.

[0033] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the written description, claims, and drawings.

[0034] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0035] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0036] Figure 1 This is a schematic diagram of the structure of the multi-purpose cementing plug in an embodiment of the present invention;

[0037] Figure 2 This is a schematic diagram showing the state of the impact head impacting the rupture disc in a cementing multi-purpose rubber plug according to an embodiment of the present invention;

[0038] Figure 3 This is a schematic diagram showing the state of the fractured disc in the cementing multi-purpose rubber plug after rupture in an embodiment of the present invention;

[0039] Explanation of reference numerals in the attached figures:

[0040] 1-Capping 2-Rubber stopper body 3-Rubber gasket 4-Sealing ring 5-Break disc

[0041] 6-Sealing ring 7-Impact sleeve 8-Sealing ring 9-Screw pin 10-Rubber stopper rubber body

[0042] 11-Impact head. Detailed Implementation

[0043] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0044] This invention provides a multi-purpose cementing plug, the structure of which can be referred to as follows. Figure 1 As shown, the rubber stopper includes: a stopper body 2, a rubber stopper body 10, an impact sleeve 7, a pin 9, a rupture disc 5, and a pressure cap 1; wherein:

[0045] The rubber stopper body 10 is fitted over the rubber stopper body 2;

[0046] One end of the pin 9 is inserted into the side wall of the impact sleeve 7, and the other end is inserted into the rubber stopper body 2; the side wall of the impact sleeve 7 is connected to the rubber stopper body 10 by the pin 9.

[0047] The rubber stopper body 10 is cylindrical, and its inner cavity is provided with an impact sleeve 7 and a rupture disc 5 from top to bottom;

[0048] The pressure cap 1 is threadedly connected to the rubber stopper body 2.

[0049] The aforementioned rubber plug body 2 and rubber plug body 10 are integrated through vulcanization. The rubber plug body 10 has a toothed shape, which serves to scrape and clean the well wall during the cementing process.

[0050] In the above-mentioned cementing multi-purpose rubber plug, an impact head 11 is provided at one end of the impact sleeve 7 facing the rupture disc 5. The impact head 11 is used to impact the edge of the rupture disc 5 when the impact sleeve 7 moves downward under pressure.

[0051] The rupture disc is made of a fragile material so that when the cementing multipurpose rubber plug is pumped to the bottom of the well, the pump pressure will increase instantaneously. Under the action of pressure, the shear pin 9 will instantly descend and the impact head 11 will hit the edge of the rupture disc 5, causing the rupture disc 5 to rupture.

[0052] In one embodiment, refer to Figure 1 As shown, the above-mentioned multi-purpose cementing plug also includes: rubber pad 3;

[0053] The rubber pad 3 is ring-shaped and is positioned between the rupture disc 5 and the pressure cap 1.

[0054] During the impact of the impact head 11 on the rupture disc 5, the rubber pad 3 can buffer the pressure on the lower cover 1, so as to reduce the impact force on the cover 1 below the rupture disc 5 when the rupture disc 5 ruptures.

[0055] In one embodiment, refer to Figure 1 As shown, the above-mentioned multi-purpose cementing plug also includes: multiple sealing rings 4; wherein:

[0056] Multiple sealing rings 4 are arranged sequentially from top to bottom on the side wall of the rubber stopper body 2, located at the position of the impact sleeve 7 and the position of the rupture disc 5, respectively.

[0057] Reference Figure 1 In the example shown, from top to bottom, the cementing multipurpose rubber plug includes three sealing rings, of which sealing ring 8 and sealing ring 6 are both located on the outside of the impact sleeve 7 to ensure that the rubber plug body 2 and the impact sleeve 7 maintain good sealing between them during the process of the impact sleeve 7 descending to impact the rupture disc 5.

[0058] The sealing ring 4 is located on the outside of the rupture disc 5, which also serves to maintain the good sealing performance of the rubber stopper body 2.

[0059] by Figure 1 Taking the structure shown as an example, the assembly process of the above-mentioned multi-purpose cementing plug provided in this embodiment of the invention is as follows:

[0060] The body 2 and the rubber stopper 10 are vulcanized together; then the sealing ring 4, sealing ring 6 and sealing ring 8 are installed into the body 2, the rupture disc 5 is installed into the body 2, the rubber gasket 3 is installed, the pressure cap 1 is threadedly connected to the body 2 and tightened; the impact sleeve 7 is installed from the top and the pin 9 is screwed on.

[0061] The multi-purpose cementing plug provided in this embodiment of the invention can be applied to a variety of scenarios. One application is as a double-plug construction method during cementing, namely an upper plug and a lower plug.

[0062] Another application method is during cementing, where it is used as a single rubber plug, also known as a rubber plug.

[0063] Another type is used as a calibration stopper during fixed operations.

[0064] Another scenario involves a cementing operation where, due to operator error, the multi-purpose cementing plug used as a pre-filled plug is prematurely released before cementing, causing blockage in the tubing string. In this case, a channel is provided for the mud to circulate, and then cementing can proceed according to the normal procedure.

[0065] In the above situations, when the cementing multi-purpose rubber plug is used as a double rubber plug in construction and is used as the lower rubber plug, the pressure level of the pin is set to one times the cementing construction pressure.

[0066] When the cementing multipurpose rubber plug is used as a double rubber plug in construction and is used as the upper rubber plug, the pressure of the pin meets the downhole rubber plug rupture pressure requirements.

[0067] When the cementing multipurpose rubber plug is used as a calibration rubber plug, the pressure rating of the pin meets the requirements for pressure observation.

[0068] Therefore, when using this cementing multipurpose rubber plug in different scenarios, the pin 9 needs to be replaced according to the actual scenario to meet the pressure requirements of different scenarios.

[0069] Specifically, when the aforementioned multi-purpose cementing plug is used in cementing operations as a dual-plug system, one of the multi-purpose cementing plugs is used as the lower plug. In this case, the pin 9 on the impact sleeve 7 is replaced to ensure its pressure meets the rupture pressure requirements of the lower plug. Then, the other multi-purpose cementing plug is used as the upper plug. In this case, the pin on the impact sleeve needs to be replaced to ensure its pressure meets the cementing requirements of the upper plug. The pressure rating of the pin 9 on the impact sleeve 7 is set to twice the cementing operation pressure.

[0070] During cementing operations, before cementing, the aforementioned lower rubber plug is first inserted and pumped to scrape and clean the well wall, serving as a separator between the lower cement slurry and mud, preventing contamination of the cement slurry. After impact, the impact sleeve 7 inside the multi-purpose cementing rubber plug provided in this embodiment of the invention shears off the pin 9 under pressure, and the downward impact head 11 impacts the edge of the rupture disc 5, causing the rupture disc 5 to rupture and providing a channel for the cement slurry, establishing circulation. Then, replacement continues, and when the multi-purpose cementing rubber plug used as the upper rubber plug is pumped to the bottom of the well for impact, the cementing is completed.

[0071] During cementing operations, when the multi-purpose cementing plug provided in this embodiment of the invention is used as a single plug, it is also used as an upper plug. At this time, the pin 9 on the impact sleeve is replaced to ensure its pressure meets the cementing requirements of the upper plug. The pressure level of the pin 9 on the impact sleeve 7 is set to one times the cementing construction pressure to meet the pressure requirements for single plug cementing. After the cementing step in the cementing operation, the multi-purpose cementing plug used as an upper plug is inserted, and the well wall is cleaned by pumping and scraping to separate the lower cement slurry from the mud, preventing contamination of the cement slurry. The plug is then pumped to the bottom of the well for impact pressing, and the cementing is completed.

[0072] During cementing operations, the multi-purpose cementing plug provided in this embodiment of the invention is used as a calibration plug. When using the multi-purpose cementing plug as a calibration plug, the pin 9 on the impact sleeve is replaced to ensure its pressure level meets the requirements for pressure observation. When the multi-purpose cementing plug is pumped to the bottom of the well, the pump pressure will increase instantaneously. Under the action of pressure, the pin 9 is sheared and the impact head 11 strikes the edge of the fracture disc 5, causing the fracture disc 5 to rupture and providing a channel for cement slurry, establishing circulation. The injection displacement is calibrated by comparing the injection displacement during pressure rise with the calculated volume.

[0073] During cementing operations, if the operator makes a mistake and releases the cementing plug used as a pre-filled plug before cementing, it can cause blockage in the tubing string. When the cementing plug is pumped to the bottom of the well, the pump pressure will increase instantaneously. When the pressure reaches the set pressure, the pin 9 will be sheared and the impact head 11 will strike the edge of the rupture disc 5. The rupture disc 5 will rupture, providing a channel for the mud. After establishing circulation, cementing can proceed according to the normal procedure.

[0074] Reference Figures 1-3 As shown, Figure 1 In the diagram, the positional relationship between the cementing multi-purpose rubber plug impact sleeve 7, the impact head 11, and the rupture disc 5 is shown. The impact head 11 is located above the rupture disc 5 and is at a certain distance from the rupture disc 5. Figure 2 The image shows the state of the impact head 11 striking the edge of the rupture disc 5 under pressure; Figure 3 The image shows the state of the ruptured disc 5 after the impact head 11 struck the edge of the ruptured disc 5, causing the disc 5 to rupture. Figures 1-3It can be seen that when the impact head 11 contacts the rubber pad 3, the rupture disc 5 is ruptured, forming a channel for the cement slurry and establishing circulation.

[0075] Based on the same inventive concept, embodiments of the present invention also provide a cementing tool and a method for using multi-purpose cementing plugs.

[0076] The cementing tool provided in this embodiment of the invention includes the multi-purpose cementing plug provided in this embodiment of the invention.

[0077] In cementing tools, cementing plugs are usually used in conjunction with baffles or float bands to achieve pressure contact.

[0078] In double-plug cementing, when the upper plug touches the lower plug, or in single-plug cementing, when the upper plug touches the baffle plate, the pressure will suddenly increase. This moment is called impact pressure.

[0079] In one embodiment, the cementing tool described above includes a multi-purpose cementing plug, which is the upper plug of the cementing tool.

[0080] The cementing multi-purpose rubber plug is in two parts, one of which is the upper rubber plug of the cementing tool, and the other is the lower rubber plug of the cementing tool.

[0081] The method for using the aforementioned multi-purpose cementing plug provided in this embodiment of the invention includes:

[0082] During cementing operations, the multi-purpose cementing plug is used as the top plug;

[0083] Alternatively, during cementing operations, the multi-purpose cementing plug can be pumped as the lower plug to scrape and clean the well wall, and after cementing, the upper plug can be inserted, and then pumped and pressed until the cementing is completed.

[0084] Alternatively, it can be used as a calibration plug during cementing operations.

[0085] This invention provides a multi-purpose cementing plug, cementing tools, and methods. The multi-purpose cementing plug includes a plug body, a rubber plug body, an impact sleeve, a pin, a rupture disc, and a pressure cap. One end of the pin is inserted into the side wall of the impact sleeve, and the other end is inserted into the plug body. The side wall of the impact sleeve is connected to the plug body via the pin. The plug body is cylindrical, and its inner cavity contains the impact sleeve and the rupture disc from top to bottom. The pressure cap is threadedly connected to the plug body. This multi-purpose cementing plug can be used in multiple stages of cementing operations, improving the quality of cementing operations. It can be used as an upper plug in the cementing process, or simultaneously as an upper and lower plug in the cementing process. It can also be used as a calibration plug in the pre-cementing slurry displacement calibration process, improving the accuracy of slurry displacement measurement and solving the problems of casing blockage and empty displacement caused by measurement issues during cementing operations in deep and ultra-deep wells. It can also provide corresponding solutions in case of cementing accidents, such as the premature release of the rubber plug before cementing causes blockage of the tubing string, thus avoiding cementing operation accidents.

[0086] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A multi-purpose cementing plug, characterized in that, include: The rubber stopper body, the rubber stopper body, the impact sleeve, the pin, the rupture disc, and the gland; The rubber body of the rubber stopper is fitted over the rubber stopper body; One end of the pin is inserted into the side wall of the impact sleeve, and the other end is inserted into the rubber plug body; the side wall of the impact sleeve is connected to the rubber plug body by the pin. The rubber stopper body is cylindrical, and its inner cavity is provided with an impact sleeve and a rupture disc from top to bottom; The gland is threadedly connected to the rubber plug body; An impact head is provided at one end of the impact sleeve facing the rupture disc. The impact head is used to impact the edge of the rupture disc when the impact sleeve moves downward under pressure.

2. The multi-purpose cementing plug as described in claim 1, characterized in that, When the cementing multipurpose rubber plug is used as a single rubber plug during construction and as an upper rubber plug, the pressure rating of the pin is set to be one times the cementing construction pressure.

3. The multi-purpose cementing plug as described in claim 1, characterized in that, When the cementing multipurpose rubber plug is used as a double rubber plug in construction and is used as the lower rubber plug, the pressure rating of the pin is set to be one times the cementing construction pressure; When the cementing multipurpose rubber plug is used as a double rubber plug in construction and is used as the upper rubber plug, the pressure of the pin meets the downhole rubber plug rupture pressure requirements.

4. The multi-purpose cementing plug as described in claim 1, characterized in that, When the cementing multipurpose rubber plug is used as a calibration rubber plug, the pressure rating of the pin meets the requirements for pressure observation.

5. The multi-purpose cementing plug as described in any one of claims 1-4, characterized in that, Also includes: rubber pad; The rubber pad is annular and is disposed between the rupture disc and the pressure cap.

6. The multi-purpose cementing plug as described in any one of claims 1-4, characterized in that, Also includes: Multiple sealing rings; The plurality of sealing rings are arranged sequentially from top to bottom on the side wall of the rubber stopper body, respectively located at the position of the impact sleeve and the position of the rupture disc.

7. A cementing tool, characterized in that, The cementing tool includes at least one cementing multipurpose rubber plug as described in any one of claims 1-6.

8. The cementing tool as described in claim 7, characterized in that, The cementing multi-purpose rubber plug is a single unit, which serves as the upper rubber plug for the cementing tool; or The cementing multi-purpose rubber plug is in two parts, one of which is the upper rubber plug of the cementing tool, and the other is the lower rubber plug of the cementing tool.

9. A method for using a cementing multipurpose rubber plug as described in any one of claims 1-6, characterized in that, include: During cementing operations, the multi-purpose cementing plug is used as the top plug; Alternatively, during cementing operations, the multi-purpose cementing plug can be pumped as the lower plug to scrape and clean the well wall, and after cementing, the upper plug can be inserted, and then pumped and pressed until the cementing is completed. Alternatively, it can be used as a calibration plug during cementing operations.

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