A differential pressure shear deformation resistant casing joint device

Abstract

This invention discloses a differential pressure type anti-shear deformation casing joint device, comprising: a packer section, divided into upper and lower packer modules, with an inlet valve system, a hydraulic piston limiting block, and a rubber sleeve on the outside of the packer, and a hydraulic module inside; the packer is connected to the casing joint inside, wherein the bottom of the lower packer contains a throttling nozzle, which can generate a positive pressure differential; a casing section, including casing joints at both ends and a double-layer casing in the middle, for fluid and cement slurry to pass through, forming an upward return channel; and a hydraulic module section, with hydraulic pipes connected to the upper casing string, containing a hydraulic piston and hydraulic oil inside. Through the positive pressure differential, the hydraulic piston is squeezed, causing the rubber sleeve to expand and seal the annular flow channel against the well wall. This device allows the cement slurry to solidify and harden inside the packer to form a double-layer casing, with a small gap between it and the well wall, providing sliding space to avoid negative effects such as reduced productivity caused by casing deformation, thereby giving the casing better shear resistance.

Description

Technical Field

[0001] This application relates to the field of oil well completion engineering technology, specifically to a differential pressure type anti-shear deformation casing joint device. Background Technology

[0002] The casing shear deformation problem stems from the fact that during multi-stage fracturing in horizontal wells, a large amount of fracturing fluid enters the natural fractures. The combined effect of the high net pressure within the fracture due to the large flow rate and the low friction coefficient of the fracture surface caused by slickwater activates the fault, leading to slippage along the natural fractures and shear deformation of the casing traversing them. To address this problem, domestic and international experts have proposed a series of prevention and control measures, including increasing the steel grade and thickness of the casing, improving the performance of the cement slurry, and adjusting hydraulic fracturing parameters. However, these measures have yielded limited results, and the casing shear deformation problem remains significant.

[0003] In addition, some scholars have proposed some downhole tools to mitigate the degree of casing deformation after fault slip: for example, Chen Xinyong et al.'s method for addressing casing deformation in enlarged but uncemented wells; Huang Zhongwei et al.'s method for preventing casing deformation in shale gas wells, which involves placing two packers at the upper boundary of the top and the lower boundary of the easily deformable section, respectively, and injecting cement slurry to eliminate the presence of cement slurry in the easily deformable section. Although this method ensures the delay of casing shear deformation when casing deformation occurs in the easily deformable section, it still poses certain safety risks to the stability of oil and gas wells and is not conducive to the long-term development of oil and gas wells.

[0004] To address this, considering the actual deformation of the casing due to fault slip shear, a differential pressure anti-shear deformation casing joint device for oil and gas wells was designed. This device adopts a differential pressure opening method inside the casing and can provide a flow channel for cement slurry during cementing. It can provide a certain slip space for the fault and significantly improve the shear resistance through double-layer casing, thereby ensuring the implementation of multi-stage hydraulic fracturing production enhancement measures. Summary of the Invention

[0005] The purpose of this application is to provide a differential pressure type anti-shear deformation sleeve joint device.

[0006] To achieve the above objectives, the first aspect of this application provides a differential pressure type anti-shear deformation sleeve joint device, the device comprising:

[0007] The packer module consists of two parts: an upper packer and a lower packer. The upper packer contains a limiting module, a hydraulic module, and a first flow channel with a double-layered sleeve. The outer side is connected to a rubber sleeve. The lower packer is connected to the upper packer through a double-layered sleeve to form a whole. The difference between the lower packer and the upper packer is that a throttling nozzle is provided at the lower end outlet of the lower packer.

[0008] The limiting module includes a limiting block sealing end cap, a limiting block rotating shaft, and a limiting block return spring, as shown in Figure 6. This module is fixed to the packer with screws, and the raised switch is embedded in the hydraulic channel. The limiting module ensures the device has unidirectional operation, guaranteeing contact between the rubber sleeve and the well wall to form a sealing annular flow channel.

[0009] The hydraulic module includes a hydraulic piston, hydraulic oil, and a rubber sleeve installed outside the device within a hydraulic pipeline. The limiting module acts as a one-way switch for the hydraulic module. The upper end of the hydraulic pipeline is fixed to the sealing end cap of the upper packer, and the lower end is open and located outside the first flow channel in the packer.

[0010] The double-layered sleeve connects the upper and lower packers, including an outer sleeve and an inner sleeve. The inner diameter of the outer sleeve is larger than the outer diameter of the inner sleeve.

[0011] In this embodiment, the device is pre-installed at locations prone to rock slippage and deformation to prevent casing shear deformation caused by rock slippage. After installation, fluid is injected into the first flow channel of the device, and some fluid flows out through the throttling nozzle of the lower packer, creating a positive pressure differential effect within the device cavity, and the hydraulic module begins to operate.

[0012] In this embodiment, the device further includes three hydraulic pipes. The hydraulic pipe in the upper packer is in a semi-closed, semi-open state and connected to the end cap of the upper packer, with the junction closed. The pipe opening faces the inside of the packer, and the inlet channel of the rubber sleeve is connected to the hydraulic pipe. The hydraulic pipe in the lower packer is in a semi-closed, semi-open state and connected to the sleeve column, with the pipe opening facing the outside of the packer and connected to the inlet channel of the rubber sleeve. The throttling nozzle is located at the bottom of the lower packer. Each hydraulic pipe contains a hydraulic piston and hydraulic oil. When the packer is subjected to a positive pressure differential, the hydraulic piston squeezes the hydraulic oil, causing it to enter the rubber sleeve and expand.

[0013] In this embodiment, the rubber sleeve is disposed on the outside of the device and is sealed to the outer wall of the main body to form a sealed pressure cavity. After cement mortar is injected into the first flow channel, a pressure difference is formed between the inside and outside of the packer. Under the action of the positive pressure difference, the first, second and third hydraulic pipelines squeeze the hydraulic oil, causing the rubber sleeve to expand continuously until it contacts the well wall and seals the annular flow channel.

[0014] In this embodiment of the application, the device further includes a first, second, and third liquid inlet channel, which are provided in both packer parts and symmetrically distributed. The upper part is in close contact with the upper packer end cap, and there is a protruding nozzle near the upper packer end cap that connects to the outer sleeve of the device through the liquid inlet channel of the rubber sleeve to form a channel. The lower opening is connected to the first flow channel and the second flow channel of the double-layer sleeve.

[0015] In this embodiment, the limiting module has three limiting blocks in each of its upper and lower parts, corresponding to three hydraulic pipes respectively. One limiting block is installed on the outside of each hydraulic pipe, and a return spring is installed inside the limiting block to give it unidirectional properties. After the hydraulic piston passes the limiting block, the return spring activates, preventing the hydraulic piston from moving back. The sealing end cap of the limiting block is embedded in the outer cylinder with screws.

[0016] In this embodiment, the double-layer concentric sleeve consists of an outer sleeve and an inner sleeve. The inner diameter of the outer sleeve is larger than the outer diameter of the inner sleeve. The outer sleeve is connected to the lower end of the upper packer and the upper end of the lower packer through an outer sleeve connector. The upper end of the inner sleeve is connected to the lower end of the upper valve seat through an inner sleeve connector. The lower end of the inner sleeve is coaxially sleeved on the upper end of the inner cylinder of the lower packer. The annular space between the outer wall of the inner sleeve and the inside of the outer sleeve forms a second fluid channel.

[0017] In the embodiments of this application, the end caps of the device, such as the upper packer end cap, the limiting block sealing end cap, and the lower packer end cap, are all connected to the device body by screws, and all of the above end caps are detachable.

[0018] In this embodiment, the double-layer casing of the device is annular within the well. Due to the expansion of the rubber sleeve to contact the well wall, a certain gap exists between the device body and the well wall. After the cement mortar solidifies, a double-layer casing is formed annular within the shale gas well.

[0019] The above technical solution comprises an upper and lower packer module, used for the passage of fluid and cement mortar, and providing space for the hydraulic module, limiting module, and inlet channel. The hydraulic module uses differential pressure to compress hydraulic oil, causing the rubber sleeve to expand and sealing the annular flow channel between the device and the wellbore. The limiting module, through a check valve, prevents the hydraulic piston from retracting after passing through the check valve, ensuring full contact between the rubber sleeve and the wellbore. The double-layer casing module, through its layered structure, forms three flow channels, allowing the liquid in the first channel to flow to the bottom and then back up to the second and third channels. This technical solution ensures a certain distance between the prepared casing and the wellbore, providing a safe sliding space when rock formations undergo slippage and deformation. This prevents the shear force from acting on the casing, reducing its impact and achieving the device's objective: improving the casing's shear resistance.

[0020] Other features and advantages of the embodiments of this application will be described in detail in the following detailed description section. Attached Figure Description

[0021] The accompanying drawings are provided to further illustrate the embodiments of this application and form part of the specification. They are used together with the following detailed description to explain the embodiments of this application, but do not constitute a limitation on the embodiments of this application. In the drawings:

[0022] Figure 1 A schematic diagram of a differential pressure anti-shear deformation sleeve joint device according to an embodiment of this application is shown.

[0023] Figure 2 A side view of a differential pressure anti-shear deformation sleeve joint device according to an embodiment of this application is shown schematically.

[0024] Figure 3 schematically shows a cross-sectional view of the differential pressure anti-shear deformation sleeve joint device according to an embodiment of this application at a designated location;

[0025] Figure 4 A schematic cross-sectional view of the upper packer of a differential pressure anti-shear deformation sleeve joint device according to an embodiment of this application is shown.

[0026] Figure 5 A schematic diagram of a hydraulic piston in a differential pressure anti-shear deformation sleeve joint device according to an embodiment of this application is shown.

[0027] Figure 6 schematically shows a limiting block of a differential pressure anti-shear deformation sleeve joint device according to an embodiment of this application.

[0028] Figure 7-9 The schematic diagram illustrates the working state of the limiting block of the differential pressure anti-shear deformation sleeve joint device.

[0029] Explanation of reference numerals in the attached figures

[0030] 1. Upper packer, 2. Casing connector, 3. Inner casing connector, 4. Outer casing connector, 5. Double casing, 6. Lower packer

[0031] 7. Throttling nozzle, 8. Packer inlet channel, 9. Hydraulic pipeline, 10. Packer fixing shear pin threaded hole

[0032] 11. Hydraulic pipeline; 12. Hydraulic piston; 13. Limit block; 14. Rubber sleeve inlet channel; 15. Inlet valve; 16. Inlet valve mounting hole.

[0033] 101. Packer body; 102. Rubber sleeve; 103. First flow channel of double-layer tube; 104. Second flow channel; 105. Third flow channel

[0034] 1301. Limit block rotating shaft; 1302. Limit block sealing end cap; 1303. Limit block return spring. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only for illustration and explanation of the embodiments of this application and are not intended to limit the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0036] First working state: After the drilling process is completed, the cementing equipment is transported to the construction section, and the instrument is in the initial state;

[0037] Second operating state: The upper packer inlet channel is open and fluid is injected into it. The upper packer inlet channel is connected to the first flow channel of the double-walled tube. The fluid flows to the lower packer through the first flow channel of the double-walled tube. At this time, the first, second, and third inlet valves of the lower packer are open. A portion of the fluid flows out of the lower packer inlet channel through the first, second, and third outlet valves of the lower packer and begins to flow back up, passing through the second flow channel of the double-walled tube until it reaches the third flow channel of the upper packer and the first, second, and third outlet valves. At this time, fluid can be observed flowing out of the outlet valves. Another portion of the fluid flows directly out of the packer through the throttling nozzle, thus creating a positive pressure difference with the packer cavity.

[0038] Third working state: The inlet of the packer's hydraulic pipeline is under high pressure, and the outlet is under low pressure. Under the action of positive pressure difference, the hydraulic pistons in the upper and lower packers are activated, squeezing the hydraulic oil in the hydraulic pipeline. The hydraulic pipeline is connected to the outer rubber sleeve, and the inflow of hydraulic oil causes the rubber sleeve to expand.

[0039] Fourth working state: Under the action of pressure difference, as hydraulic oil is continuously squeezed into the rubber sleeve, it will continuously expand until it contacts the wellbore, thereby sealing the annular flow channel between the packer and the well wall. At this time, the hydraulic piston is squeezed into the instrument to the limit block. The return spring of the limit block makes it have a one-way action, preventing the rubber sleeve from retracting due to the return of the hydraulic piston.

[0040] Fifth working state: After the annular flow channels between the rubber sleeves of the upper and lower packers and the wellbore are sealed, cement mortar is injected into the wellhead. When the cement mortar returns from the bottom of the well to the position of the lower packer, due to the expansion of the rubber sleeve of the lower packer sealing the annular flow channels, the cement mortar will flow from the first flow channel of the lower packer through the second flow channel of the double-layer casing to the third flow channel inside the upper packer. Due to the expansion of the rubber sleeve of the upper packer sealing the annular flow channels, the cement mortar flows out from the outlet valve of the upper packer. Stop injecting cement mortar.

[0041] During the fracturing process of shale gas horizontal wells, the movement of pore water in the rock formation can lead to rock slippage and casing shear deformation, severely reducing the service life and efficiency of the shale gas well. This tool aims to create a double layer of casing around the well, increasing its shear strength. When this cementing device is lowered into the location of the rock fracture, the resulting double layer of casing and wellbore wall form an annular space, providing space for fault slippage and thus mitigating casing shear deformation.

Claims

1. A differential pressure type anti-shear deformation sleeve joint device, characterized in that, include: The packer comprises two parts: an upper packer and a lower packer. The lower packer and the upper packer are connected as a whole by a double-layered sleeve. The upper packer contains a limiting module, a hydraulic module, and a first flow channel of the double-layered sleeve. The first flow channel of the double-layered sleeve is connected to the liquid inlet channel of the upper packer. The upper end of the flow channel is fixed to the sealing end cap of the upper packer. Three hydraulic pipes from the hydraulic module are also fixed to the sealing end cap of the upper packer. The sealing end cap of the limiting module is fixed to the outside of the packer by screws. The protruding switch in the limiting module is embedded in the hydraulic pipes. The outside of the upper packer is connected to a rubber sleeve. A throttling nozzle is also provided at the lower outlet of the lower packer. The limit module includes a limit block sealing end cap, a limit block rotating shaft, and a limit block return spring. The limit block sealing end cap and the convex switch are connected through the limit block rotating shaft and the return spring. The convex switch is embedded in the hydraulic pipeline and is reset by the return spring. The hydraulic module includes a hydraulic piston and hydraulic oil inside the hydraulic pipeline, and a rubber sleeve installed outside the differential pressure anti-shear deformation sleeve joint device; the hydraulic piston is located close to the sealing end cover of the upper packer inside the hydraulic pipeline, followed by the hydraulic oil, which is located between the hydraulic piston and the inlet channel, and flows into the rubber sleeve through the inlet channel, causing the rubber sleeve to expand; the limiting module is a one-way switch of the hydraulic module, the upper end of the hydraulic pipeline is fixed to the sealing end cover of the upper packer, and the lower end is open and located outside the first flow channel in the packer; The double-layered sleeve includes an outer sleeve and an inner sleeve. The inner diameter of the outer sleeve is larger than the outer diameter of the inner sleeve. There are three flow channels inside the double-layered sleeve. The first flow channel is located inside the inner sleeve, and its length extends from the upper packer sealing end cap to the lower packer sealing end cap. The second flow channel is located between the two walls of the inner sleeve, and the third flow channel is located between the two walls of the outer sleeve. The differential pressure anti-shear deformation casing joint device is pre-placed and installed at locations prone to rock slippage deformation to prevent casing shear deformation caused by rock slippage. After installation, drilling and completion fluid is injected into the first flow channel, and some fluid flows out through the throttling nozzle at the lower end of the lower packer. A positive pressure difference is formed in the upper and lower packer cavities, and the hydraulic module starts to work under the action of the pressure difference. Each of the upper and lower packers has three hydraulic pipes. One end of each hydraulic pipe is fixed to the sealing end cap of the upper and lower packers and is evenly distributed in an equilateral triangle. The other end opens inward and connects to the packer cavity. The three hydraulic pipes are not distinguished by their order. In the upper packer, the hydraulic pipes are in a semi-closed and semi-open state and are connected to the sealing end cap of the upper packer. The junction is closed, and the pipe openings face inward to the packer. The inlet channel of the rubber sleeve is connected to the hydraulic pipes. In the lower packer, the hydraulic pipes are in a semi-closed and semi-open state and are connected to the sleeve column. The pipe openings face outward to the packer and are connected to the inlet channel of the rubber sleeve. The throttling nozzle is located at the bottom of the lower packer. The hydraulic pipes contain a hydraulic piston device and hydraulic oil. When the packer is subjected to a positive pressure differential, the hydraulic piston squeezes the hydraulic oil, causing it to enter the rubber sleeve and thus expand. The differential pressure shear deformation resistant sleeve joint device also includes a first, second, and third liquid inlet channel, which are provided in the upper and lower packer parts and are symmetrically distributed. The upper part is in close contact with the sealing end cap of the upper packer, and there is a protruding nozzle near the sealing end cap of the upper packer. It is connected to the outer sleeve of the differential pressure shear deformation resistant sleeve joint device through the liquid inlet channel of the rubber sleeve to form a channel. The lower opening is connected to the first flow channel and the second flow channel of the double-layer sleeve. The limiting module has three limiting blocks in each of the upper and lower parts, corresponding to three hydraulic pipes respectively. Each hydraulic pipe has a limiting block on its outer side and a return spring inside, making it unidirectional. After the hydraulic piston passes the limiting block, the return spring takes effect and prevents the hydraulic piston from moving back.

2. The differential pressure type anti-shear deformation sleeve joint device according to claim 1, characterized in that, The rubber sleeve is located on the outside and is sealed to the outer wall of the upper and lower packers to form a sealed pressure cavity. Cement mortar is injected into the first flow channel, and a pressure difference is formed between the inside of the cavity of the upper and lower packers and the outside of the packers. Under the action of the positive pressure difference, the first, second and third hydraulic pipelines squeeze the hydraulic oil, causing the rubber sleeve to expand until it contacts the well wall and seals the annular flow channel.

3. The differential pressure type anti-shear deformation sleeve joint device according to claim 1, characterized in that, The upper packer sealing end cap, the limit block sealing end cap, and the lower packer sealing end cap are all connected to the packer by screws, and all of the above end caps are removable.

4. The differential pressure type anti-shear deformation sleeve joint device according to claim 1, characterized in that, The double-layer casing annulus of the differential pressure anti-shear deformation casing joint device is located in the well.

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