An expandable packer with a sliding sleeve and method of use

Abstract

The application discloses a kind of extruded inflatable sealed staged cementing tools and use method, belong to the well cementing technical field in petroleum drilling completion engineering, the tool includes shell body, fixed with the closing sleeve made of inflatable metal material in shell body, fixed with O-shaped sealing ring on closing sleeve, after closing circulating hole, closing sleeve and O-shaped sealing ring can be deformed and form high-strength air seal structure under the extrusion of closing plug down.The application designs the closing sleeve prepared using inflatable metal material, which can produce permanent plastic expansion deformation under the extrusion of closing plug down after closing circulating hole, and the O-shaped sealing ring will be deformed under the extrusion of closing sleeve, so that the closing sleeve can form a high-strength air seal structure, even in high temperature and high pressure environment, it can also form a long-term stable seal for circulating hole, solving the technical problems of poor sealing ability of existing tools and short stable sealing time.

Description

Technical Field

[0001] This invention belongs to the field of cementing technology in oil drilling and completion engineering, specifically relating to a staged cementing tool with an extrusion expandable seal and its usage method. Background Technology

[0002] Cementing is a crucial step in drilling and completion. After the casing is run in, cementing must be performed to seal the annulus between the casing and the wellbore. As the drilling scale of deep wells, ultra-deep wells, and horizontal wells gradually increases, the amount of cement slurry injected in a single cementing operation is too large, the construction time is long, and it is easy to cause insufficient return depth, resulting in cementing quality often not being guaranteed.

[0003] Currently, staged cementing is mainly used in oilfields to address issues such as low cementing efficiency and poor cementing quality. Staged cementing tools are crucial for achieving staged cementing, and the shut-off sleeve is the component used to close the circulation port after the staged cementing operation. As part of the casing string, if the shut-off sleeve fails to effectively seal the circulation port after closure, downhole fluid leakage is highly likely, impacting subsequent operations such as oil and gas extraction. This is particularly critical for CCUS test areas and acidic oil and gas reservoirs containing corrosive gases such as CO2 and H2S; the gas-tight sealing capability of the staged cementing tool after closing the circulation port is essential for ensuring wellbore integrity.

[0004] Currently, the closing sleeve of a staged cementing tool typically includes a closing plug seat and a closing slide sleeve. The process of closing the circulation hole involves controlling the downward movement of the closing plug, which in turn moves the closing plug seat and closing slide sleeve downwards. After the closing slide sleeve closes the circulation hole, the closing plug seat disengages. This conventional staged cementing tool relies primarily on two sets of O-rings on the upper and lower parts of the closing slide sleeve for sealing and flow interruption, with a sealing strength of approximately 20 MPa. However, in the complex downhole working conditions, the closing slide sleeve cannot effectively seal the circulation hole for extended periods, resulting in limited sealing capacity and poor practicality.

[0005] To improve the sealing effect of existing staged cement injection tools after closing the circulation hole, the following related technologies have been proposed in the prior art: For example, patent document CN204492741U discloses a gas-sealing graded collar for oil and gas wells. However, this technology mainly improves the gas-sealing capability of graded cementing tools by simplifying the mechanical structure and optimizing the assembly method of graded cementing tools. In essence, it still uses the threads of the upper and lower collars and O-rings for gas sealing. The sealing method has not changed, but only the possibility of breaking the seal has been reduced. Therefore, its sealing capability has not been improved in essence.

[0006] For example, patent document CN212898414U discloses a compensating sealing graded clamp. This technology mainly involves designing a compensating sealing sleeve on the closing sleeve. The compensating sealing sleeve expands upon contact with the fluid in the cement slurry at the exposed part of the circulation hole, thus providing an auxiliary seal. Essentially, it utilizes the chemical properties of the material to expand upon contact with the fluid, thereby compensating for the sealing of the circulation hole. However, this chemically expanding material is located at the circulation hole, and its high-temperature and high-pressure resistance is not as stable as that of metallic materials. This makes it prone to sealing failure in the high-temperature and high-pressure environment downhole, resulting in poor timeliness of its stable seal.

[0007] Therefore, it is necessary to provide a new technology that provides stable sealing with long service life and can significantly improve sealing performance in order to solve the above-mentioned technical problems. Summary of the Invention

[0008] The purpose of this invention is to overcome the aforementioned problems in the prior art and to provide a graded cement injection tool and its usage method with an extrusion-expandable seal. This invention designs a closing sleeve made of expandable metal material. After closing the circulation hole, the closing sleeve can undergo permanent plastic expansion deformation under the downward extrusion action of the closing plug. At the same time, the O-ring seal also deforms under the extrusion action of the closing sleeve. Through the simultaneous action of the extrusion deformation of the O-ring seal and the expansion deformation of the closing sleeve, the closing sleeve can form a high-strength gas-tight structure, which can form a stable seal for the circulation hole for a long time even under high temperature and high pressure environments. This solves the technical problems of poor sealing ability and short stable sealing time of existing tools.

[0009] To achieve the above objectives, the technical solution adopted by the present invention is as follows: In a first aspect, the present invention provides a graded cement injection tool with an extrusion expandable seal, comprising a housing body, wherein a closing sleeve made of expandable metal material is fixed above the circulation hole inside the housing body by a shear pin, and an O-ring is fixed on the closing sleeve. After the circulation hole is closed, the closing sleeve and the O-ring can deform under the downward extrusion action of the closing plug to form a high-strength airtight structure.

[0010] After the closing sleeve closes the circulation hole, it can undergo permanent plastic expansion deformation under the downward squeezing action of the closing plug, and the O-ring can deform under the squeezing action of the closing sleeve.

[0011] The expanded metal material is low-carbon steel or duplex stainless steel.

[0012] The sealing strength of the gas-tight structure is 35-50 MPa.

[0013] The closing sleeve includes a closing plug seat and a closing slide sleeve. The outer wall of the closing plug seat has an annular groove that matches the closing slide sleeve, and the closing slide sleeve is fitted into the annular groove. One end of the shear pin is fixed to the outer shell body, and the other end is fixed to the closing slide sleeve. The O-rings are located between the closing plug seat and the outer shell body and between the closing plug seat and the closing slide sleeve, respectively.

[0014] The O-rings are located at the upper and lower parts between the closing plug and the outer shell, and at the upper, middle and lower parts between the closing plug and the closing slide.

[0015] The lower end of the annular groove is a right-angled structure, and the upper part is a conical structure.

[0016] The upper opening end of the closing plug seat is provided with a tapered guide surface for guiding the closing plug in.

[0017] The upper end of the outer shell body is fixed with an upper coupling, and an inner limiting ring platform is provided below the upper coupling. The closing sleeve is located between the inner limiting ring platform and the circulation hole.

[0018] Secondly, the present invention provides a method for using a staged cement injection tool with an expandable seal, the method being based on a closing plug seat and a closing sliding sleeve both made of expandable metal material, and comprising the following steps: Step A: After cementing is completed, press in the shut-off plug and circulate to replace the drilling fluid, pressing the shut-off plug into the top of the shut-off plug seat; Step B: Pressurize and circulate drilling fluid until the shear pin is sheared off. The closing plug will push the closing plug seat and closing sleeve downwards to the closing circulation hole. Step C: Continue pressurizing and circulating the drilling fluid to allow the shut-off plug to continue descending. At this point, the shut-off plug will enter the interior of the shut-off plug seat and pass through it. During the process of the shut-off plug passing through the shut-off plug seat, the shut-off plug will forcefully squeeze the shut-off plug seat, causing permanent plastic deformation and tightly fitting it onto the shut-off sliding sleeve. At the same time, the O-rings located between the shut-off plug seat and the outer shell body and the O-rings located between the shut-off plug seat and the shut-off sliding sleeve will deform synchronously, thereby forming a high-strength gas-tight structure for the circulation hole.

[0019] The advantages of using this invention are: 1. The tool described in this invention is designed with a shut-off sleeve made of expandable metal material. After closing the circulation hole, the shut-off sleeve undergoes permanent plastic expansion deformation under the downward compression of the shut-off plug. Simultaneously, the O-ring seal deforms under the compression of the shut-off sleeve. Through the combined action of the O-ring seal's compression deformation and the shut-off sleeve's expansion deformation, the shut-off sleeve forms a high-strength gas-tight structure, providing a long-term stable seal for the circulation hole even under high temperature and high pressure environments. This significantly improves sealing capacity and extends the duration of stable sealing. Furthermore, for acidic oil and gas reservoirs containing CO2 and H2S, it effectively prevents corrosive gases from leaking and corroding through the circulation hole, thus maintaining the integrity of the wellbore during subsequent operations.

[0020] 2. The expansion metal material in this invention can be low-carbon steel or duplex stainless steel. Low-carbon steel has a lower carbon content, better plasticity and toughness, is easy to process and form, and has a relatively low cost, but its strength is relatively low. It is suitable for use in some scenarios where the strength requirements of the expansion tube are not particularly high, or when it is used as a base material for further processing, such as the fabrication of expansion tubes in some early simple oil well repair operations. Duplex stainless steel has the advantages of high strength and high plasticity, and its work hardening rate is relatively high, which can better maintain shape stability and mechanical properties during expansion. Its yield strength can reach 640MPa-650MPa, and its elongation can reach 30%-33%, which can better meet the strength and plasticity requirements of the expansion tube before and after expansion. For acidic oil and gas reservoirs containing corrosive gases such as CO2 and H2S, it is recommended to use duplex stainless steel 2205 as the processing material for the shut-off plug.

[0021] 3. The sealing strength of the gas-tight structure in this invention can reach 35-50MPa. Its advantage is that after the metal expansion of the closing plug seat, the closing plug seat that fits on the closing slide sleeve is equivalent to forming a metal sealing ring, thereby forming a metal + rubber double seal for the circulation hole.

[0022] 4. The present invention sets the lower end of the annular groove as a right-angle structure and the upper part as a conical structure. Its advantage is that it facilitates the downward compression of the closing plug seat by the closing plug and causes permanent deformation of the closing plug seat.

[0023] 5. The present invention has a tapered guide surface at the upper opening end of the closing plug seat for guiding the closing plug in, and the tapered guide surface facilitates the accurate entry of the closing plug into the closing plug seat.

[0024] 6. The method of use described in this invention differs from conventional staged cementing tools, which only employ a closing sleeve with a sliding hole and two sets of sealing rings. This invention, based on the conventional closing sleeve with a hole, uses an expanded metal material closing plug seat that deforms to tightly fit the closing sliding sleeve. Simultaneously, multiple sets of corrosion-resistant O-rings enhance the sealing performance, thus solving the problem of insufficient gas sealing performance in staged cementing tools. Especially for acidic oil and gas reservoirs containing CO2 and H2S, it can effectively prevent corrosive gases from leaking and corroding through the circulation hole, thereby maintaining the integrity of the wellbore during subsequent operations. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the structure of the present invention before the circulation hole is closed; Figure 2 This is a schematic diagram of the structure after the initial sealing circulation hole of the closed sleeve is closed according to the present invention; Figure 3 This is a schematic diagram of the structure of the present invention when a high-strength gas-tight structure is formed after the plug is squeezed and expanded.

[0026] The markings in the diagram are: 1. Upper coupling, 2. Outer shell body, 3. Closing plug seat, 4. Closing slide sleeve, 5. Shear pin, 6. Circulation hole, 7. O-ring seal, 8. Closing plug, 9. Closing plug cone. Detailed Implementation

[0027] Example 1 like Figure 1-3 As shown, this invention provides a compression-expandable sealing graded cement injection tool, comprising a housing body 2, an upper coupling 1 fixed inside the upper end of the housing body 2, an inner limiting ring platform below the upper coupling 1, a circulation hole 6 in the middle of the housing body 2, and a closing sleeve fixed above the circulation hole 6 by a shear pin 5. The closing sleeve is specifically located between the inner limiting ring platform and the circulation hole 6. The closing sleeve can be made of a metal material with expansion properties, such as low carbon steel or duplex stainless steel, so that the closing sleeve has the characteristic of expanding and deforming under compression. In addition, an O-ring 7 made of corrosion-resistant material is also fixed on the closing sleeve.

[0028] After the cement injection is completed and the circulation hole 6 is closed with the closing sleeve, the closing sleeve and O-ring 7 can deform under the downward squeezing action of the closing plug 8 to form a high-strength airtight structure. Specifically, after the circulation hole 6 is closed, the closing sleeve can undergo permanent plastic expansion deformation under the downward squeezing action of the closing plug 8, and the O-ring 7 can deform under the squeezing action of the closing sleeve. The combination of the two forms a high-strength airtight structure.

[0029] Furthermore, compared to closure sleeves made of conventional metal materials, the closure sleeve made of expanded metal material in this invention can achieve a sealing strength of 35-50 MPa after forming an airtight structure, which greatly improves the sealing performance of the closure sleeve.

[0030] According to a preferred embodiment of the present invention, such as Figure 1-3 As shown, the closing sleeve includes a closing plug seat 3 and a closing sliding sleeve 4. Both the closing plug seat 3 and the closing sliding sleeve 4 are hollow cylindrical structures. An annular groove adapted to the closing sliding sleeve 4 is formed in the middle of the outer wall of the closing plug seat 3, and the closing sliding sleeve 4 is fitted into the annular groove. One end of the shear pin 5 is fixed to the outer shell body 2, and the other end is fixed to the lower part of the closing sliding sleeve 4. O-rings 7 are located between the closing plug seat 3 and the outer shell body 2 and between the closing plug seat 3 and the closing sliding sleeve 4, respectively.

[0031] Furthermore, the outer diameter of the closing plug 3 is adapted to the inner diameter of the outer shell 2, and the inner diameter of the closing plug 3 is smaller than the inner diameter of the inner limiting ring. The outer diameter of the closing sleeve 4 is the same as the outer diameter of the closing plug 3, and the thickness of the closing sleeve 4 is the same as the depth of the annular groove. The closing sleeve 4 fits snugly into the closing plug 3 through the annular groove. It should be noted that a retaining ring is threaded to the lower part of the closing plug 3, and the closing sleeve 4 is fixed to the closing plug 3 by the retaining ring. In addition, the lower end of the annular groove is a right-angle structure, and the upper part is a conical structure. Correspondingly, the lower end of the closing sleeve 4 is a right-angle structure, and the upper end is an inclined structure adapted to the conical structure.

[0032] According to another optional embodiment of the present invention, the number of O-rings 7 can be five sets, wherein two sets of O-rings 7 are located at the upper and lower parts between the closing plug seat 3 and the outer shell body 2, respectively, and the other three sets of O-rings 7 are located at the upper, middle, and lower parts between the closing plug seat 3 and the closing sleeve 4, respectively. These five sets of O-rings 7 will deform synchronously when the closing sleeve is compressed, thereby further enhancing the sealing ability of the closing sleeve.

[0033] According to another preferred embodiment of the present invention, in order to facilitate the accurate entry of the closing plug 8 into the closing seat, the upper opening end of the closing plug seat 3 is provided with a tapered guide surface for guiding the closing plug 8 into the closing seat.

[0034] It should be noted that the lower end of the closing plug 8 is provided with a closing plug cone 9. The outer diameter of the lower end of the closing plug cone 9 is smaller than the outer diameter of the upper end. At the same time, the outer diameter of the lower end of the closing plug cone 9 is smaller than the inner diameter of the closing plug seat 3, while the outer diameter of the upper end of the closing plug cone 9 is larger than the outer diameter of the closing plug seat 3. This allows the closing plug 8 to effectively compress the closing plug seat 3 and the closing sleeve 4 when it moves downward. In addition, the outer diameter of the upper end of the closing plug cone 9 is preferably such that the closing plug 8 can effectively compress the closing plug seat 3 and cause the closing sleeve to undergo permanent plastic expansion deformation when it moves downward.

[0035] The usage process in this embodiment is as follows: 1. Figure 1 A structural schematic diagram shows the initial state and position of the closing plug 3 and the closing sleeve 4 before the downward closing circulation hole 6. At this time, the closing sleeve is fixed to the outer shell body 2 by shear pins 5 and is located above the circulation hole 6 and below the upper coupling 1.

[0036] 2. After the secondary cementing is completed, the shut-off plug 8 is pressed in, and then the drilling fluid is circulated to push the shut-off plug 8 above the shut-off plug seat 3. The two are locked together due to their conical structure, located at the upper coupling 1 of the staged cementing tool. Then, the shear pin 5 fixing the shut-off sleeve is sheared off by pressure. The shut-off plug 8 moves downward, pushing the shut-off plug seat 3 and the shut-off sliding sleeve 4 downward, thereby closing the circulation hole 6 and completing the two-stage cementing operation. Figure 2 As shown.

[0037] 3. Then, continue pressurizing and circulating the drilling fluid. The shut-off plug 8 continues to descend. At this time, the conical structure on the shut-off plug 8 forcibly compresses the interior of the shut-off plug seat 3. Since both the shut-off plug seat 3 and the shut-off sliding sleeve 4 are made of expandable metal, the expandable metal undergoes permanent plastic deformation under compression, tightly adhering to the shut-off sliding sleeve 4. This improves the closing effect of the circulation hole 6. Simultaneously, the five sets of corrosion-resistant O-ring seals 7 deform under the metal compression, working in conjunction with the metal expansion of the shut-off plug seat 3 to form a metal sealing ring, thus creating a... Figure 3 The high-strength gas-tight structure shown further enhances the sealing capability of the closing sleeve.

[0038] Because the present invention can form the above-mentioned high-strength gas-tight structure, it can form a stable seal for a long time even under high temperature and high pressure environment, thus greatly improving the sealing ability and the stability of the seal.

[0039] Example 2 This invention provides a method for using a graded cement injection tool with an expandable seal, which, based on Example 1, utilizes a closing plug seat 3 and a closing sliding sleeve 4 both made of expandable metal material. The method includes the following steps: Step A: As Figure 2 As shown, after cementing is completed, the shut-off plug 8 is pressed in and the drilling fluid is circulated to replace it, pressing the shut-off plug 8 above the shut-off plug seat 3.

[0040] Step B: Pressurize and circulate the drilling fluid until the shear pin 5 is sheared off. The closing plug 8 will push the closing plug seat 3 and the closing sleeve 4 downward to the closing circulation hole 6.

[0041] Step C: As Figure 3As shown, the drilling fluid is continuously pressurized and circulated, causing the shut-off plug 8 to continue to descend. At this time, the shut-off plug 8 will enter the interior of the shut-off plug seat 3 and pass through the shut-off plug seat 3. During the process of the shut-off plug 8 passing through the shut-off plug seat 3, the shut-off plug 8 will forcefully squeeze the shut-off plug seat 3, causing the shut-off plug seat 3 to undergo permanent plastic deformation and tightly fit onto the shut-off sliding sleeve. At the same time, the O-ring seals 7 located between the shut-off plug seat 3 and the outer shell body 2 and the O-ring seals 7 located between the shut-off plug seat 3 and the shut-off sliding sleeve 4 will deform synchronously, thereby forming a high-strength gas-tight structure for the circulation hole 6.

[0042] The specific structure and advantages involved in this embodiment can be found in Embodiment 1, and will not be repeated here.

[0043] The above description is merely a specific embodiment of the present invention. Any feature disclosed in this specification may be replaced by other equivalent or similar features unless otherwise specified. All features or steps in the disclosed methods or processes may be combined in any way, except for mutually exclusive features and / or steps.

Claims

1. A compressible expandable seal graded cement injection tool, comprising a housing body (2), characterized in that: A closing sleeve made of expandable metal material is fixed above the circulation hole (6) inside the outer shell body (2) by a shear pin (5). An O-ring (7) is fixed on the closing sleeve. After the closing sleeve closes the circulation hole (6), the closing sleeve and the O-ring (7) can deform under the downward squeezing action of the closing plug (8) and form a high-strength airtight structure.

2. The graded cement injection tool with an extrusion-expandable sealing mechanism according to claim 1, characterized in that: After the closing sleeve closes the circulation hole (6), the closing sleeve can undergo permanent plastic expansion deformation under the downward squeezing action of the closing plug (8), and the O-ring seal (7) can deform under the squeezing action of the closing sleeve.

3. The graded cement injection tool with an extrusion-expandable sealing mechanism according to claim 1, characterized in that: The expansion metal material is low-carbon steel or duplex stainless steel.

4. The staged cement injection tool with an extrusion-expandable sealing mechanism according to claim 1, characterized in that: The sealing strength of the gas-tight structure is 35-50 MPa.

5. The staged cement injection tool with an extrusion-expandable sealing mechanism according to claim 1, characterized in that: The closing sleeve includes a closing plug seat (3) and a closing slide sleeve (4). The outer wall of the closing plug seat (3) is provided with an annular groove that is adapted to the closing slide sleeve (4). The closing slide sleeve (4) is fitted in the annular groove. One end of the shear pin (5) is fixed on the outer shell body (2), and the other end is fixed on the closing slide sleeve (4). The O-ring seal (7) is located between the closing plug seat (3) and the outer shell body (2) and between the closing plug seat (3) and the closing slide sleeve (4).

6. The staged cement injection tool with an extrusion-expandable seal according to claim 5, characterized in that: The O-rings (7) are located at the upper and lower parts between the closing plug (3) and the outer shell body (2), and at the upper, middle and lower parts between the closing plug (3) and the closing sleeve (4).

7. The staged cement injection tool with an extrusion-expandable sealing mechanism according to claim 5, characterized in that: The lower end of the annular groove is a right-angled structure, and the upper part is a conical structure.

8. The graded cement injection tool with an extrusion-expandable sealing mechanism according to claim 1, characterized in that: The upper opening end of the closing plug seat (3) is provided with a tapered guide surface for guiding the closing plug (8) into place.

9. A graded cement injection tool with an extrusion-expandable sealing mechanism according to claim 1, characterized in that: The upper end of the outer shell body (2) is fixed with an upper coupling (1), and an inner limiting ring platform is provided below the upper coupling (1). The closing sleeve is located between the inner limiting ring platform and the circulation hole (6).

10. A method of using a compression-expandable sealing graded cement injection tool, characterized in that: This method is based on a closing plug seat (3) and a closing slide sleeve (4) both made of expanded metal material, and includes the following steps: Step A: After cementing is completed, press in the shut-off plug (8) and circulate to replace the drilling fluid, pressing the shut-off plug (8) above the shut-off plug seat (3); Step B: Pressurize and circulate drilling fluid until the shear pin (5) is sheared off. The closing plug (8) will push the closing plug seat (3) and the closing sleeve (4) downward to the closing circulation hole (6). Step C: Continue to pressurize and circulate the drilling fluid, so that the shut-off plug (8) continues to descend. At this time, the shut-off plug (8) will enter the interior of the shut-off plug seat (3) and pass through the shut-off plug seat (3). During the process of the shut-off plug (8) passing through the shut-off plug seat (3), the shut-off plug (8) will forcefully squeeze the shut-off plug (8), causing the shut-off plug seat (3) to undergo permanent plastic deformation and tightly fit onto the shut-off sliding sleeve (4). At the same time, the O-ring seals (7) located between the shut-off plug seat (3) and the outer shell body (2) and the O-ring seals (7) located between the shut-off plug seat (3) and the shut-off sliding sleeve (4) will deform synchronously, thereby forming a high-strength gas-tight structure for the circulation hole (6).

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