Isolation packers and sand control tubing

Abstract

This invention relates to an isolation packer and a sand control tubing string. The isolation packer includes an upper central tube and a lower central tube, with an intermediate joint fixedly connected between the upper and lower central tubes. An upper joint is fixedly connected to the upper end of the upper central tube. An expansion sleeve assembly is fitted over the upper central tube between the upper joint and the intermediate joint. The expansion sleeve assembly is used to achieve a sealing function by expanding under pressure. An expansion sleeve assembly is also fitted over the lower central tube. The expansion sleeve assembly is used to achieve a sealing function by self-expansion. The expansion sleeve assembly of this invention meets the sand control sealing requirements during the well completion operation stage, and meets the high-temperature sealing requirements during the heat injection and well simmering stages, as well as the sealing requirements under alternating temperatures during the production stage.

Description

Technical Field

[0001] This invention belongs to the field of open-hole horizontal well development technology in heavy oil fields, specifically relating to an isolation packer and a sand control string. Background Technology

[0002] Heavy oil horizontal well development requires multiple rounds of steam injection and flushing. During the heating, shut-in, and production stages, the temperature and pressure at the bottom of the well undergo drastic changes. The sand control tubing must withstand multiple cycles of hot and cold temperatures throughout the thermal recovery well's production cycle. Therefore, the effectiveness of the sand control tubing must be extended as much as possible, meeting the requirements for sand control sealing during the completion stage, high-temperature sealing during the heating and shut-in stages, and sealing under alternating temperatures during the production stage. Open-hole packers are key tools for achieving precise sand control and balanced steam injection in horizontal sections. Most existing open-hole packers use expansion-type sealing elements, mainly of two structures: one type generates axial load under hydraulic or mechanical force to compress the rubber sleeve to achieve a seal. This type of packer has a low pressure differential resistance and is prone to failure in high-temperature environments; the other type achieves a seal by self-expansion of the rubber sleeve upon contact with oil or water. This type of packer has a long expansion time, which severely restricts the efficient and economical development of thermal recovery wells. Summary of the Invention

[0003] To address all or part of the aforementioned problems, the present invention aims to provide an isolation packer and a sand control tubing string, wherein the expansion sleeve assembly meets the filling and sand control sealing requirements during the well completion operation stage, and the expansion sleeve assembly meets the high-temperature sealing requirements during the heating and well-closing stages, as well as the sealing requirements under alternating temperatures during the production stage.

[0004] According to one aspect of the present invention, an isolation packer is provided, comprising an upper central tube and a lower central tube, an intermediate joint being fixedly connected between the upper central tube and the lower central tube, an upper joint being fixedly connected to the upper end of the upper central tube, an expansion sleeve assembly being sleeved on the upper central tube between the upper joint and the intermediate joint, a first annular space being provided between the expansion sleeve assembly and the upper central tube, the expansion sleeve assembly being used to achieve a sealing function by expanding under pressure;

[0005] The lower central tube is fitted with an expansion rubber sleeve assembly, which is used to seal by self-expansion. The upper end of the expansion rubber sleeve assembly is fixedly connected to the intermediate joint. The lower ends of the lower central tube and the expansion rubber sleeve assembly are both connected to the switch assembly. A second annular space is provided between the lower central tube and the expansion rubber sleeve assembly.

[0006] The upper connector has a first bypass hole, the lower part of the switch assembly is connected to a lower connector, the lower connector has a second bypass hole, and the intermediate connector has a first channel. The first bypass hole, the first annulus, the first channel, the second annulus, the flow channel of the switch assembly, and the second bypass hole form an axial flow channel that is connected in sequence. The axial flow channel is normally in a conductive state, and the switch assembly can be operated by an external mechanical switching tool to make the axial flow channel cut off.

[0007] Furthermore, the expansion sleeve assembly includes an upper sleeve mandrel, the upper end of which is fixedly connected to the outer side of the valve body, the upper end of the upper central tube is fixedly connected to the inner side of the valve body, and the upper end of the valve body is fixedly connected to the upper connector.

[0008] The lower end of the upper glue cylinder mandrel is fixedly connected to the intermediate joint, and the first annular space is formed between the upper glue cylinder mandrel and the upper central tube. An expansion glue cylinder is sleeved on the outside of the upper glue cylinder mandrel. The upper end of the expansion glue cylinder is sealed to the outside of the valve body, and the lower end of the expansion glue cylinder is sealed to the intermediate joint. The expansion glue cylinder is used to achieve a sealing function by expanding under pressure.

[0009] The valve body is provided with a pressure channel, one end of which is used to cooperate with the pressure hole of the setting tool, and the other end of which is connected to the annulus between the expansion tube and the upper tube mandrel; the valve body is provided with a second channel, which is connected to the first bypass hole and the first annulus.

[0010] Furthermore, along the flow direction of the pressurizing liquid, an opening valve, a check valve, and a shut-off valve are sequentially arranged on the pressurizing channel. The opening valve is used to open under a set pressure to make the pressurizing channel open. The one-way valve is open in the same direction as the flow direction of the pressurizing liquid. The shut-off valve is used to achieve hydraulic locking after the expansion sleeve is set.

[0011] Furthermore, the upper connector includes an upper short section, which is fixedly connected to the inner side of the upper end of the valve body. An upper outer cylinder is fixedly connected to the outer side of the upper end of the valve body. There is a gap between the upper short section and the upper outer cylinder. The first bypass hole is provided on the upper outer cylinder. The upper end of the upper outer cylinder is fixedly connected to the middle part of the upper short section. An upper connecting structure is provided on the upper end of the upper short section extending out of the upper outer cylinder. The upper connecting structure is used to connect to the pipe column above it.

[0012] The upper end of the expansion tube is sealed with an upper pressure ring, which is fixedly connected to the valve body; the lower end of the expansion tube is sealed with a lower pressure ring, which is fixedly connected to the intermediate joint.

[0013] Furthermore, the expansion sleeve assembly includes a lower sleeve mandrel, the upper end of which is fixedly connected to the outer side of the intermediate joint, a second annular space is formed between the lower sleeve mandrel and the lower central tube, an expansion sleeve is sleeved on the outside of the lower sleeve mandrel, the expansion sleeve is used to perform a sealing function through self-expansion, the expansion sleeve is limited between the intermediate joint and the switch assembly, and the lower end of the lower sleeve mandrel is connected to the switch assembly.

[0014] Furthermore, the expanding rubber tube includes an expanding rubber tube body, an expanding metal is disposed inside the expanding rubber tube body, the expanding metal is capable of self-expanding and driving the expanding rubber tube body to expand, and a soluble layer is disposed on the outer surface of the expanding rubber tube body.

[0015] Limiting rings are respectively provided at the upper end and the lower end of the expansion rubber cylinder body.

[0016] Furthermore, the lower ends of the lower central tube and the lower rubber cylinder mandrel are both connected to the switch assembly through an intermediate short section. A third annular cavity is provided inside the intermediate short section, and the third annular cavity connects the second annular cavity and the flow channel of the switch assembly.

[0017] Furthermore, the intermediate short section includes a connecting mandrel and an outer cylinder. The lower end of the lower central tube is sealed to the inner wall of the connecting mandrel. The lower end of the lower rubber sleeve mandrel is fixedly connected to the outer wall of the connecting mandrel. The outer side of the lower rubber sleeve mandrel is fixedly connected to the upper end of the outer cylinder. A third annular space is formed between the outer cylinder and the connecting mandrel. A first connecting hole is provided on the lower rubber sleeve mandrel between the upper end of the outer cylinder and the upper end of the connecting mandrel. The first connecting hole connects the third annular space and the second annular space. Both the outer cylinder and the connecting mandrel are connected to the switch assembly.

[0018] Furthermore, the switch assembly includes an upper closing cylinder, a lower closing cylinder, and a connecting sleeve. The upper end of the upper closing cylinder is fixedly connected to the inner side of the connecting spindle, the upper end of the connecting sleeve is fixedly connected to the outer side of the connecting spindle, the lower end of the connecting sleeve is fixedly connected to the upper end of the closing body, the upper end of the connecting sleeve is fixedly connected to the outer cylinder, and the lower end of the closing body is fixedly connected to the lower connector.

[0019] The upper closing cylinder is provided with a sliding sleeve, and the upper closing cylinder is provided with an upper locking groove that engages with the locking pawl ratchet at the upper end of the sliding sleeve. The outer wall of the sliding sleeve is sealed to the lower end of the upper closing cylinder, and the outer wall of the sliding sleeve is sealed to the upper end of the lower closing cylinder. The lower closing cylinder is provided with a lower locking groove that engages with the locking pawl ratchet at the lower end of the sliding sleeve. The lower end of the lower closing cylinder is fixedly connected to the lower connector.

[0020] A second connecting hole is provided on the connecting sleeve between the upper end of the connecting sleeve and the lower end of the outer cylinder. The second connecting hole connects the third annulus and the flow channel.

[0021] Under normal conditions, the locking claw ratchet at the lower end of the sliding sleeve is located in the lower locking groove. The flow channel is formed by the annular space between the upper closing cylinder and the connecting sleeve, the annular space between the upper closing cylinder and the closing body, the annular space between the sliding sleeve and the closing body, and the annular space between the lower closing cylinder and the closing body. The flow channel is in the open state.

[0022] A closing boss is provided on the inner wall of the closing body, and a closing protrusion is provided on the outer wall of the lower part of the sliding sleeve. By driving the sliding sleeve upward with an external mechanical switching tool, the locking claw ratchet at the upper end of the sliding sleeve can be moved into the upper locking groove. At this time, the closing protrusion contacts the closing boss, and the axial flow channel is in a closed state.

[0023] Furthermore, the lower connector includes a lower outer cylinder, the upper end of which is fixedly connected to the lower end of the closing body, the second bypass hole is provided on the lower outer cylinder, there is a gap between the lower outer cylinder and the lower closing cylinder, the lower ends of the lower outer cylinder and the lower closing cylinder are both fixedly connected to the lower short section, and the lower end of the lower short section is provided with a lower connecting structure, which is used to connect with the pipe column below it.

[0024] The present invention also provides a sand-proof tubing string, including the isolation packer described in any one of the above.

[0025] As can be seen from the above technical solution, the isolation packer and sand control pipe provided by the present invention have the following beneficial effects:

[0026] The expansion sleeve assembly of the present invention meets the filling and sand-prevention sealing requirements during the well completion operation stage, and meets the high-temperature sealing requirements during the heating and well-closing stages, as well as the sealing requirements under alternating temperatures during the production stage.

[0027] The isolation packer of this invention can meet the sealing reliability and long-term effectiveness of thermal recovery wells throughout their entire life cycle, and to a certain extent avoids cross-contamination and interference between layers, providing technical support for the implementation of subsequent process measures such as segmented acidizing, segmented fracturing, segmented water shut-off, and segmented steam injection. Attached Figure Description

[0028] Figure 1 This is a cross-sectional view of the upper part of an isolation packer according to an embodiment of the present invention;

[0029] Figure 2 This is a cross-sectional view of the middle portion of an isolation packer according to an embodiment of the present invention;

[0030] Figure 3 This is a cross-sectional view of the lower portion of an isolation packer according to an embodiment of the present invention;

[0031] The attached figures are labeled as follows: 1. Upper connector; 2. Sealing cylinder; 3. Upper coupling; 4. Upper short section; 5. Upper outer cylinder; 5. First bypass hole; 51. Valve body; 6. Second channel; 61. Expanding rubber sleeve; 7. Upper rubber sleeve mandrel; 8. Upper central tube; 9. Intermediate connector; 10. First channel; 101. Lower central tube; 11. Connecting mandrel; 12. Outer cylinder; 13. Connecting sleeve; 14. Second connecting hole; 141. Upper closing cylinder; 15. Upper locking groove; 151. Sliding sleeve; 16. Lock. Fixed claw ratchet 161, closing protrusion ring 162, closing body 17, closing boss 171, lower closing cylinder 18, lower locking groove 181, lower outer cylinder 19, second bypass hole 191, lower short section 20, lower coupling 21, lower connector 22, lower rubber cylinder spindle 23, first connecting hole 231, expansion rubber cylinder 24, upper pressure ring 25, lower pressure ring 26, limiting ring 27, first annular cavity 28, second annular cavity 29, third annular cavity 30. Detailed Implementation

[0032] To better understand the purpose, structure, and function of this invention, a detailed description of an isolation packer and sand control pipe string of this invention is provided below with reference to the accompanying drawings.

[0033] like Figures 1-3 As shown, it illustrates an isolation packer according to an embodiment of the present invention, including an upper central tube 9 and a lower central tube 11. An intermediate joint 10 is fixedly connected between the upper central tube 9 and the lower central tube 11. An upper joint is fixedly connected to the upper end of the upper central tube 9. An expansion sleeve assembly is sleeved on the upper central tube 9 between the upper joint and the intermediate joint 10. A first annular space 28 is provided between the expansion sleeve assembly and the upper central tube 9. The expansion sleeve assembly is used to achieve a sealing effect by expanding under pressure.

[0034] The lower center tube 11 is fitted with an expansion rubber cylinder assembly, which is used to seal by self-expansion. The upper end of the expansion rubber cylinder assembly is fixedly connected to the intermediate joint 10. The lower ends of the lower center tube 11 and the expansion rubber cylinder assembly are both connected to the switch assembly. A second annular space 29 is provided between the lower center tube 11 and the expansion rubber cylinder assembly.

[0035] The upper connector has a first bypass hole 51, and the lower part of the switch assembly is connected to a lower connector. The lower connector has a second bypass hole 191, and the intermediate connector 10 has a first channel 101. The first bypass hole 51, the first annular space 28, the first channel 101, the second annular space 29, the flow channel of the switch assembly, and the second bypass hole 191 form an axial flow channel that is connected in sequence. The axial flow channel is normally in a conductive state, and the switch assembly can be operated by an external mechanical switching tool to make the axial flow channel cut off.

[0036] The packer in this embodiment can meet the sealing reliability and long-term effectiveness of thermal recovery wells throughout their entire life cycle, and to a certain extent avoid cross-contamination and interference between layers, providing technical support for the implementation of subsequent process measures such as segmented acidizing, segmented fracturing, segmented water shut-off, and segmented steam injection.

[0037] Specifically, the packer in this embodiment includes an upper central tube 9 and a lower central tube 11, which are fixedly connected by an intermediate joint 10. The upper end of the upper central tube 9 is fixedly connected to the upper joint. An expansion sleeve assembly is disposed outside the upper central tube 9 between the upper joint and the intermediate joint 10. The expansion sleeve assembly is used to seal the annulus between the tubing string and the wellbore during well completion operations.

[0038] The axial flow channel in this embodiment is designed to allow the sand-carrying fluid to pass through during sand-control filling operations. Specifically, the sand-carrying fluid enters the first bypass hole 51 from the annulus between the tubing and the wellbore. Then, the sand-carrying fluid flows along the flow channels of the first annulus 28, the first channel 101, the second annulus 29, and the switch assembly to the second bypass hole 191. Finally, the sand-carrying fluid flows through the second bypass hole 191 into the annulus between the tubing and the wellbore below the expansion sleeve assembly, thereby achieving the purpose of filling the annulus with the sand-carrying fluid. The axial flow channel in this embodiment allows the sand-carrying fluid to cross the expansion sleeve assembly and the expansion sleeve assembly during the filling stage, enabling the filling of multiple layers in a single tubing run.

[0039] In this embodiment, the switch assembly is configured to close the axial flow channel after filling is completed. Once the axial flow channel is closed, subsequent hot injection and well-steaming operations can begin.

[0040] Furthermore, in this embodiment, the lower central tube 11 is fitted with an expansion sleeve assembly, which is used to seal the annulus between the tubing string and the wellbore through self-expansion. After the axial flow channel is closed, the outer diameter of the expansion sleeve assembly gradually expands to its maximum. At this time, both the expansion sleeve assembly and the expansion sleeve assembly simultaneously provide a sealing function, ensuring the reliability of the seal.

[0041] As the heating process proceeds, the expansion sleeve assembly fails under high temperatures, and the expansion sleeve assembly then plays a primary sealing role, achieving effective interlayer sealing during the heating phase. Furthermore, the expansion sleeve assembly of this embodiment maintains good sealing performance across multiple rounds of heating production.

[0042] In summary, the expansion sleeve assembly in this embodiment meets the filling and sand-prevention sealing requirements during the well completion operation stage, and meets the high-temperature sealing requirements during the heating and well-closing stages, as well as the sealing requirements under alternating temperatures during the production stage.

[0043] In practice, the intermediate joint 10 and the upper central tube 9, and the intermediate joint 10 and the lower central tube 11 are all threaded connections.

[0044] In one embodiment, such as Figures 1-2 As shown, the expansion tube assembly includes an upper tube spindle 8, the upper end of which is fixedly connected to the outer side of the valve body 6, the upper end of the upper central tube 9 is fixedly connected to the inner side of the valve body 6, and the upper end of the valve body 6 is fixedly connected to the upper connector.

[0045] The lower end of the glue-filling cylinder spindle 8 is fixedly connected to the intermediate joint 10. A first annular space 28 is formed between the glue-filling cylinder spindle 8 and the upper central tube 9. An expansion glue cylinder 7 is sleeved on the outside of the glue-filling cylinder spindle 8. The upper end of the expansion glue cylinder 7 is sealed to the outside of the valve body 6, and the lower end of the expansion glue cylinder 7 is sealed to the intermediate joint 10. The expansion glue cylinder 7 is used to achieve a sealing effect by expanding under pressure.

[0046] The valve body 6 is provided with a pressure channel. One end of the pressure channel is used to cooperate with the pressure hole of the setting tool, and the other end of the pressure channel is connected to the annulus between the expansion tube 7 and the top tube spindle 8. The valve body 6 is provided with a second channel 61, which is connected to the first bypass hole 51 and the first annulus 28.

[0047] Specifically, the expansion tube assembly of this embodiment includes an upper tube mandrel 8 and an expansion tube 7. The upper end of the upper tube mandrel 8 is fixedly connected to the outer side of the valve body 6, the lower end of the upper tube mandrel 8 is fixedly connected to the intermediate joint 10, the upper end of the upper central tube 9 is fixedly connected to the inner side of the valve body 6, the upper tube mandrel 8 is sleeved on the upper central tube 9, and the annular space between the upper tube mandrel 8 and the upper central tube 9 is the aforementioned first annular space 28.

[0048] In specific implementation, the inner wall of the valve body 6 is threaded to the upper end of the upper central tube 9, and the inner wall of the valve body 6 is threaded to the upper rubber sleeve spindle 8. The first annular space 28 between the upper central tube 9 and the upper rubber sleeve spindle 8 communicates with the second channel 61 on the valve body 6. The lower end of the upper central tube 9 is threaded to the intermediate connector 10, and the lower end of the upper rubber sleeve spindle 8 is pinned to the intermediate connector 10. The first annular space 28 between the upper central tube 9 and the upper rubber sleeve spindle 8 communicates with the first channel 101 on the intermediate connector 10. The material of the expanding rubber sleeve 7 is nitrile rubber.

[0049] The expansion sleeve 7 is fitted outside the upper sleeve mandrel 8. One end of the pressure channel of the valve body 6 is engaged with the pressure hole of the setting tool, and the other end is connected to the annulus between the expansion sleeve 7 and the upper sleeve mandrel 8. Therefore, when the setting tool pressurizes the pressure channel, the liquid in the pressure channel enters the annulus between the expansion sleeve 7 and the upper sleeve mandrel 8. Finally, the liquid in the annulus causes the expansion sleeve 7 to expand to seal the annulus between the packer string and the wellbore.

[0050] The upper end of the expansion sleeve 7 is sealed to the outside of the valve body 6, and the lower end of the expansion sleeve 7 is sealed to the intermediate joint 10. This is to form a closed annulus between the expansion sleeve 7 and the upper sleeve mandrel 8, thereby ensuring that the expansion sleeve 7 can be successfully seated.

[0051] In one embodiment, along the flow direction of the pressurizing liquid, an opening valve, a check valve, and a shut-off valve are sequentially arranged on the pressurizing channel. The opening valve is used to open under a set pressure to make the pressurizing channel open. The flow direction of the check valve is the same as the flow direction of the pressurizing liquid. The shut-off valve is used to achieve hydraulic locking after the expansion sleeve 7 is set.

[0052] In this embodiment, an opening valve, a check valve, and a shut-off valve are sequentially arranged on the pressure channel. The opening valve is used to open under a set pressure to make the pressure channel open. For example, the opening valve opens under an opening pressure of 9MPa. The opening valve increases the pressure of the liquid entering the annulus between the expanding rubber cylinder 7 and the upper rubber cylinder mandrel 8. The check valve is used to ensure that the liquid can only flow in one direction, that is, only from the setting tool to the annulus between the expanding rubber cylinder 7 and the upper rubber cylinder mandrel 8. The shut-off valve is used to achieve hydraulic locking after the expanding rubber cylinder 7 is set, thereby ensuring that the expanding rubber cylinder 7 is always in the expanded state and ensuring the setting force of the expanding rubber cylinder 7.

[0053] In one embodiment, such as Figure 1 As shown, the upper connector includes an upper short section 4, which is fixedly connected to the inner side of the upper end of the valve body 6. An upper outer cylinder 5 is fixedly connected to the outer side of the upper end of the valve body 6. There is a gap between the upper short section 4 and the upper outer cylinder 5. A first bypass hole 51 is provided on the upper outer cylinder 5. The upper end of the upper outer cylinder 5 is fixedly connected to the middle part of the upper short section 4. An upper connecting structure is provided on the upper end of the upper short section 4 extending out of the upper outer cylinder 5. The upper connecting structure is used to connect to the pipe column above it.

[0054] In this embodiment, the upper connector includes an upper short section 4 and an upper outer cylinder 5. The upper short section 4 is fixedly connected to the inner side of the upper end of the valve body 6, and the upper outer cylinder 5 is fixedly connected to the outer side of the upper end of the valve body 6. A first bypass hole 51 is provided on the upper outer cylinder 5. The first bypass hole 51 connects to the annulus between the tubing string and the wellbore. The first bypass hole 51 connects to the second channel 61 of the valve body 6 through the gap between the upper short section 4 and the upper outer cylinder 5. Therefore, the sand-carrying fluid injected from the annulus between the tubing string and the wellbore can flow into the axial flow channel through the first bypass hole 51.

[0055] The upper connecting structure is set at the upper end of the upper short section 4 extending from the upper outer cylinder 5. The purpose of connecting the upper end of the isolation packer in this embodiment to connect with the tube column above it is achieved by setting the upper connecting structure.

[0056] Secondly, the upper short section 4 can extend from the upper outer cylinder 5 and be threadedly connected to the upper coupling 3. The upper coupling 3 is threadedly connected to the sealing cylinder 2, and the sealing cylinder 2 is threadedly connected to the upper connector 1, thereby achieving the lengthening of the isolation packer. The upper connection structure is set at the upper end of the upper connector 1.

[0057] The upper end of the expansion tube 7 is sealed with an upper pressure ring 25, which is fixedly connected to the valve body 6; the lower end of the expansion tube 7 is sealed with a lower pressure ring 26, which is fixedly connected to the intermediate joint 10.

[0058] In one embodiment, such as Figure 2 As shown, the expansion sleeve assembly includes a lower sleeve mandrel 23. The upper end of the lower sleeve mandrel 23 is fixedly connected to the outer side of the intermediate joint 10. A second annular space 29 is formed between the lower sleeve mandrel 23 and the lower central tube 11. An expansion sleeve 24 is sleeved on the outside of the lower sleeve mandrel 23. The expansion sleeve 24 is used to seal by self-expansion. The expansion sleeve 24 is limited between the intermediate joint 10 and the switch assembly. The lower end of the lower sleeve mandrel 23 is connected to the switch assembly.

[0059] Specifically, the expansion tube assembly includes a lower tube mandrel 23 and an expansion tube 24. The upper end of the lower central tube 11 and the upper end of the lower tube mandrel 23 are both fixedly connected to the lower end of the intermediate connector 10. The aforementioned second annular space 29 is formed between the lower tube mandrel 23 and the lower central tube 11. The second annular space 29 is connected to the first channel 101 on the intermediate connector 10.

[0060] The expansion sleeve 24 is fitted over the lower sleeve spindle 23. The expansion sleeve 24 is used to seal by self-expansion. The expansion sleeve 24 is positioned between the intermediate connector 10 and the switch assembly.

[0061] In one embodiment, the expanding rubber tube 24 includes an expanding rubber tube 24 body, an expanding metal is disposed inside the expanding rubber tube 24 body, the expanding metal can expand on its own and drive the expanding rubber tube 24 body to expand, and a soluble layer is disposed on the outer surface of the expanding rubber tube 24 body.

[0062] In this embodiment, the soluble layer is provided to protect the body of the expansion sleeve 24. The soluble layer is, for example, a metal coating applied to the body of the expansion sleeve 24. This metal coating can dissolve in the well fluid. By controlling the thickness of the metal coating, the time for the metal coating to completely dissolve can be controlled, thereby achieving, for example, that the metal coating is completely dissolved after the filling operation is completed. After the metal coating dissolves, the body of the expansion sleeve 24 transfers the heat of the well fluid or the heat of the hot water injected from the wellhead to the expansion metal. The expansion metal expands and deforms due to the heat, and the expansion deformation of the expansion metal drives the body of the expansion sleeve 24 to expand and achieve setting and sealing.

[0063] In this embodiment, the expansion metal is, for example, a shape memory alloy with a one-way memory effect. The shape memory alloy is in a compressed state at room temperature, and when the temperature rises, the shape memory alloy expands to restore its original size.

[0064] Limiting rings 27 are respectively provided at the upper end and the lower end of the expanding rubber cylinder 24 body. In this embodiment, the limiting rings 27 are provided to prevent the expanding rubber cylinder 24 body from expanding along the axial direction, so that the expanding rubber cylinder 24 body can only expand along its diameter direction.

[0065] In one embodiment, such as Figure 2 As shown, the lower ends of the lower central tube 11 and the lower rubber cylinder spindle 23 are both connected to the switch assembly through an intermediate short section. A third annular cavity 30 is provided inside the intermediate short section, and the third annular cavity 30 connects the second annular cavity 29 and the flow channel of the switch assembly.

[0066] Specifically, the lower end of the lower central tube 11 is connected to the intermediate short section, the lower end of the lower rubber sleeve mandrel 23 is connected to the intermediate short section, the intermediate short section is connected to the switch assembly, the second annular space 29 between the lower rubber sleeve mandrel 23 and the lower central tube 11 communicates with the third annular space 30 inside the intermediate short section, and the third annular space 30 inside the intermediate short section communicates with the flow channel of the switch assembly. In this embodiment, the expansion rubber sleeve 24 is confined between the intermediate joint 10 and the intermediate short section.

[0067] The intermediate short section includes a connecting spindle 12 and an outer cylinder 13. The lower end of the lower central tube 11 is sealed to the inner wall of the connecting spindle 12. The lower end of the lower rubber tube spindle 23 is fixedly connected to the outer wall of the connecting spindle 12. The outer side of the lower rubber tube spindle 23 is fixedly connected to the upper end of the outer cylinder 13. A third annular space 30 is formed between the outer cylinder 13 and the connecting spindle 12. A first connecting hole 231 is provided on the lower rubber tube spindle 23 between the upper end of the outer cylinder 13 and the upper end of the connecting spindle 12. The first connecting hole 231 connects the third annular space 30 and the second annular space 29. Both the outer cylinder 13 and the connecting spindle 12 are connected to the switch assembly.

[0068] Specifically, the intermediate short section includes a connecting mandrel 12 and an outer cylinder 13, forming the aforementioned third annular space 30 between the outer cylinder 13 and the connecting mandrel 12. A first connecting hole 231 on the lower rubber sleeve mandrel 23 is located between the upper end of the outer cylinder 13 and the upper end of the connecting mandrel 12. The first connecting hole 231 is provided to connect the second annular space 29 and the third annular space 30, allowing liquid in the second annular space 29 to enter the third annular space 30 through the first connecting hole 231.

[0069] In this embodiment, the lower end of the lower central tube 11 is sealed to the inner wall of the connecting mandrel 12, thereby preventing the liquid in the second annulus 29 from flowing into the connecting mandrel 12 through the gap between the lower central tube 11 and the connecting mandrel 12. This ensures that the sand-carrying fluid can only flow through the axial flow channel to the annulus between the tubing string and the well wall. In this embodiment, both the outer cylinder 13 and the connecting mandrel 12 are connected to the switching assembly, and the third annulus 30 is connected to the flow channel of the switching assembly.

[0070] In one embodiment, such as Figures 2-3 As shown, the switch assembly includes an upper closing cylinder 15, a lower closing cylinder 18, and a connecting sleeve 14. The upper end of the upper closing cylinder 15 is fixedly connected to the inner side of the connecting spindle 12, the upper end of the connecting sleeve 14 is fixedly connected to the outer side of the connecting spindle 12, the lower end of the connecting sleeve 14 is fixedly connected to the upper end of the closing body 17, the upper end of the connecting sleeve 14 is fixedly connected to the outer cylinder 13, and the lower end of the closing body 17 is fixedly connected to the lower connector.

[0071] The upper closing cylinder 15 is provided with a sliding sleeve 16, and the upper closing cylinder 15 is provided with an upper locking groove 151 that engages with the locking pawl ratchet 161 at the upper end of the sliding sleeve 16. The outer wall of the sliding sleeve 16 is sealed to the lower end of the upper closing cylinder 15, and the outer wall of the sliding sleeve 16 is sealed to the upper end of the lower closing cylinder 18. The lower closing cylinder 18 is provided with a lower locking groove 181 that engages with the locking pawl ratchet 161 at the lower end of the sliding sleeve 16. The lower end of the lower closing cylinder 18 is fixedly connected to the lower connector.

[0072] A second connecting hole 141 is provided on the connecting sleeve 14 between the upper end of the connecting sleeve 14 and the lower end of the outer cylinder 13. The second connecting hole 141 connects the third annulus 30 and the flow channel.

[0073] In normal operation, the locking claw ratchet 161 at the lower end of the sliding sleeve 16 is located in the lower locking groove 181. The flow channel is formed by the annulus between the upper closing cylinder 15 and the connecting sleeve 14, the annulus between the upper closing cylinder 15 and the closing body 17, the annulus between the sliding sleeve 16 and the closing body 17, and the annulus between the lower closing cylinder 18 and the closing body 17. The flow channel is in the open state.

[0074] The inner wall of the closing body 17 is provided with a closing boss 171, and the outer wall of the lower part of the sliding sleeve 16 is provided with a closing protrusion 162. By driving the sliding sleeve 16 upward through an external mechanical switch tool, the locking claw ratchet 161 at the upper end of the sliding sleeve 16 can be moved into the upper locking groove 151, and at this time the closing protrusion 162 contacts the closing boss 171, and the axial flow channel is in a closed state.

[0075] Specifically, the switch assembly includes an upper closing cylinder 15, a lower closing cylinder 18, a connecting sleeve 14, and a sliding sleeve 16. The upper part of the sliding sleeve 16 is sealed to the lower end of the upper closing cylinder 15, and the lower part of the sliding sleeve 16 is sealed to the upper end of the lower closing cylinder 18. The third annular cavity 30 and the flow channel are connected through a second connecting hole 141, which is located on the connecting sleeve 14 between the upper end of the connecting sleeve 14 and the lower end of the outer cylinder 13.

[0076] Under normal conditions, the sliding sleeve 16 moves down to the lower limit position under the action of gravity. When the sliding sleeve 16 is in the lower limit position, the locking claw ratchet 161 at the lower end of the sliding sleeve 16 is located in the lower locking groove 181 of the lower closing cylinder 18. At this time, the annulus between the upper closing cylinder 15 and the connecting sleeve 14, the annulus between the upper closing cylinder 15 and the closing body 17, the annulus between the sliding sleeve 16 and the closing body 17, and the annulus between the lower closing cylinder 18 and the closing body 17 are connected in sequence. The axial flow channel is in the open state, and the sand-carrying fluid can flow to the annulus between the tubing string and the well wall through the axial flow channel.

[0077] The sliding sleeve 16 can also move upward under the action of an external mechanical switching tool. After the sliding sleeve 16 moves upward to the upper limit position, the locking claw ratchet 161 at the upper end of the sliding sleeve 16 is located in the upper locking groove 151 inside the upper closing cylinder 15. At this time, the closing boss 171 on the inner wall of the closing body 17 fits with the closing protrusion 162 on the lower outer wall of the sliding sleeve 16. At this time, the axial flow channel is closed, and the sand-carrying fluid cannot flow through the axial flow channel to the annulus between the tubing and the well wall.

[0078] Among them, such as Figure 3 As shown, the lower connector includes a lower outer cylinder 19, the upper end of which is fixedly connected to the lower end of the closing body 17. A second bypass hole 191 is provided on the lower outer cylinder 19. There is a gap between the lower outer cylinder 19 and the lower closing cylinder 18. The lower ends of both the lower outer cylinder 19 and the lower closing cylinder 18 are fixedly connected to the lower short section 20. The lower end of the lower short section 20 is provided with a lower connecting structure, which is used to connect with the pipe column below it.

[0079] In this embodiment, the lower connector includes a lower outer cylinder 19 and a lower short section 20. The lower end of the closing body 17 is fixedly connected to the upper end of the lower outer cylinder 19, and the lower ends of both the lower outer cylinder 19 and the lower closing cylinder 18 are fixedly connected to the lower short section 20. The lower connecting structure is located at the lower end of the lower short section 20 and is used to connect the isolation packer of this embodiment to the tubing below it.

[0080] The second bypass hole 191 is provided on the lower outer cylinder 19. The second bypass hole 191 connects the annulus between the tubing string and the wellbore. The second bypass hole 191 connects the flow channel of the switch assembly through the gap between the lower outer cylinder 19 and the lower shut-off cylinder 18. Therefore, the sand-carrying fluid in the axial flow channel can flow into the annulus between the tubing string and the wellbore through the second bypass hole 191.

[0081] Secondly, in specific implementation, the lower end of the lower short section 20 can also be threadedly connected to the lower coupling 21, and the lower coupling 21 is connected to the lower connector 22. The lower connection structure is set at the lower end of the lower connector 22, thereby realizing the lengthening of the isolation packer.

[0082] The isolation packer in this embodiment includes an expansion tube assembly, an upper central tube 9, an intermediate joint 10, a lower central tube 11, an expansion tube assembly, a connecting sleeve 14, an upper closing tube 15, a sliding sleeve 16, a closing body 17, a lower closing tube 18, etc. The upper connector 1 is threaded to the sealing cylinder 2, the sealing cylinder 2 is threaded to the upper coupling 3, the upper coupling 3 is threaded to the upper outer cylinder 5 and the valve body 6, the valve body 6 is threaded to the upper central tube 9 and the upper rubber tube spindle 8, the expansion rubber tube 7 is sleeved on the upper rubber tube spindle 8, the upper central tube 9 and the lower central tube 11 are connected by the intermediate joint 10, the upper end of the lower rubber tube spindle 23 is threaded to the intermediate joint 10, the lower end of the lower rubber tube spindle 23 is threaded to the connecting spindle 12, the outer cylinder is sleeved on the connecting spindle 12, the connecting spindle 12 is threaded to the connecting sleeve 14 and the upper closing cylinder 15, the sliding sleeve 16 is fitted with the upper closing cylinder 15 and the lower closing cylinder 18, the lower outer cylinder 19 is threaded to the lower closing cylinder 18 and the lower short section 20 respectively, the lower outer cylinder 19 is fixed to the closing body 17 by screws, the lower short section 20 is threaded to the lower coupling 21, and the lower coupling 21 is connected to the lower connector 22.

[0083] This invention also provides a method for using an isolation packer, comprising the following steps:

[0084] Step 10: Connect the packer to the sand control string, and connect the packer setting tool to the service tool string. Run the string into position. After the string is in place, the setting port of the service tool string's setting tool is aligned with one end of the pressure channel of valve body 6. Positive circulation pressure buildup occurs, and the fluid flow opening valve, check valve, and locking valve act on the expansion sleeve 7 until it is tightly pressed against the wellbore, achieving setting. After setting, the hydraulic pressure is locked by the locking valve. This locking of the hydraulic pressure ensures the long-term effectiveness of the setting of the expansion sleeve 7 during the well completion phase.

[0085] Step 20: Gravel backfilling is performed at the backfilling location. The sand-carrying liquid flows through the axial flow channel and exits from the second bypass hole 191 to achieve backfilling of multiple layers. In this embodiment, the backfilling operation saves time. After backfilling is completed, an external mechanical switch tool moves the sliding sleeve 16 upward to close the axial flow channel.

[0086] Step 30: Remove the service tool string and run the production string into the sand control string for production completion. The soluble layer on the surface of the expansion sleeve 24 is completely dissolved, and the expansion sleeve 24 gradually expands to its maximum outer diameter. At this time, the expansion sleeve 7 and the expansion sleeve 24 simultaneously play a sealing role, ensuring the reliability of the seal.

[0087] Step 40: High-temperature steam is injected into the pipe. The expansion sleeve 7 fails under high temperature, and the expansion sleeve 24 plays a major sealing role, achieving effective interlayer sealing during the heating stage.

[0088] Step 50: During the production phase, the downhole temperature is gradually reduced to ambient temperature, and high-temperature steam is injected again. This cycle is repeated multiple times to extract heavy oil. The expansion sleeve 24 is made of high-temperature material, maintaining good sealing performance throughout the process and contributing to the efficient development of heavy oil fields.

[0089] This invention also provides a sand control pipe column, which includes the isolation packer of any of the above embodiments.

[0090] The sand control tubing of this invention can be used throughout the entire lifecycle of a thermal recovery well, including during the completion, injection, and production stages. Furthermore, the expansion sleeve assembly meets the sand control sealing requirements during the completion phase, and satisfies the high-temperature sealing requirements during injection and well-closing phases, as well as the sealing requirements under alternating temperatures during the production stage.

[0091] It should be noted that, unless otherwise stated, the technical or scientific terms used in this application should have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains.

[0092] Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly defined.

[0093] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0094] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered within the scope of the claims and specification of the present invention. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. The present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. An isolation packer, comprising: The upper center tube and the lower center tube are fixedly connected with an intermediate joint, the upper end of the upper center tube is fixedly connected with an upper joint, the upper center tube between the upper joint and the intermediate joint is sleeved with an expansion rubber sleeve assembly, the expansion rubber sleeve assembly and the upper center tube are provided with a first annular space, and the expansion rubber sleeve assembly serves to seal by being pressed and expanded. The lower center tube is sleeved with an expansion rubber sleeve assembly, the expansion rubber sleeve assembly serves to seal by self-expansion, the upper end of the expansion rubber sleeve assembly is fixedly connected with the intermediate joint, the lower center tube and the lower end of the expansion rubber sleeve assembly are connected with a switch assembly, and the lower center tube and the expansion rubber sleeve assembly are provided with a second annular space. A first bypass hole is formed in the upper joint, the lower part of the switch assembly is connected with a lower joint, a second bypass hole is formed in the lower joint, a first channel is arranged on the intermediate joint, the first bypass hole, the first annular space, the first channel, the second annular space, a flow channel of the switch assembly and the second bypass hole form a shaft flow channel which is sequentially communicated, the shaft flow channel is in a conductive state in a normal state, and the switch assembly can be actuated by an external mechanical switch tool to make the shaft flow channel in a cut-off state. The isolation packer further comprises a closing main body, the switch assembly comprises an upper closing cylinder, a lower closing cylinder and a connecting sleeve, a sliding sleeve is arranged in the upper closing cylinder, an upper locking groove is arranged in the upper closing cylinder and matched with locking pawl ratchets at the upper end of the sliding sleeve, the outer wall of the sliding sleeve is sealingly connected with the lower end of the upper closing cylinder, the outer wall of the sliding sleeve is sealingly connected with the upper end of the lower closing cylinder, a lower locking groove is arranged in the lower closing cylinder and matched with locking pawl ratchets at the lower end of the sliding sleeve, and the lower end of the lower closing cylinder is fixedly connected with the lower joint. In the normal state, the locking pawl ratchets at the lower end of the sliding sleeve are located in the lower locking groove, the flow channel is formed by an annular space between the upper closing cylinder and the connecting sleeve, an annular space between the upper closing cylinder and the closing main body, an annular space between the sliding sleeve and the closing main body and an annular space between the lower closing cylinder and the closing main body, and the flow channel is in an open state. A closing boss is arranged on the inner wall of the closing main body, a closing convex ring is arranged on the lower part of the outer wall of the sliding sleeve, the sliding sleeve can be driven to move upwards by an external mechanical switch tool, the locking pawl ratchets at the upper end of the sliding sleeve can be moved into the upper locking groove, the closing convex ring is in contact with the closing boss at this time, and the shaft flow channel is in a cut-off state.

2. The isolating packer of claim 1, wherein, The isolation packer further comprises a valve body, the expansion rubber sleeve assembly comprises an upper rubber sleeve shaft, the upper end of the upper rubber sleeve shaft is fixedly connected with the outer side of the valve body, the upper end of the upper center tube is fixedly connected with the inner side of the valve body, and the upper end of the valve body is fixedly connected with the upper joint. The lower end of the rubberizing cylinder mandrel is fixedly connected with the intermediate joint, the rubberizing cylinder mandrel and the upper central pipe form the first annular space, the rubberizing cylinder mandrel is externally sleeved with an expansion rubber sleeve, the upper end of the expansion rubber sleeve is sealingly connected with the outer side of the valve body, the lower end of the expansion rubber sleeve is sealingly connected with the intermediate joint, and the expansion rubber sleeve is used for sealing by pressure expansion. The valve body is provided with a pressure channel, one end of the pressure channel is used for cooperating with a pressure hole of a setting tool, and the other end of the pressure channel is communicated with the annular space between the expansion rubber sleeve and the rubberizing cylinder mandrel; the valve body is provided with a second channel, and the second channel is communicated with the first bypass hole and the first annular space.

3. The isolating packer of claim 2, wherein, The pressure channel is sequentially provided with an opening valve, a check valve and a stop valve along the flow direction of the pressure liquid, the opening valve is used for opening the pressure channel to be in a conductive state under a set pressure, the conductive direction of the check valve is the same as the flow direction of the pressure liquid, and the stop valve is used for realizing hydraulic locking after the expansion rubber sleeve is set.

4. The isolating packer of claim 2, wherein, The upper joint comprises an upper short section, the upper short section is fixedly connected with the inner side of the upper end of the valve body, the outer side of the upper end of the valve body is fixedly connected with an upper outer cylinder, the upper short section and the upper outer cylinder have a gap, the first bypass hole is arranged on the upper outer cylinder, the upper end of the upper outer cylinder is fixedly connected with the middle part of the upper short section, the upper short section which protrudes from the upper end of the upper outer cylinder is provided with an upper connecting structure, and the upper connecting structure is used for being connected with a pipe string above the upper connecting structure. The upper end of the expansion rubber sleeve is sealingly connected with an upper pressure ring, the upper pressure ring is fixedly connected with the valve body, the lower end of the expansion rubber sleeve is sealingly connected with a lower pressure ring, and the lower pressure ring is fixedly connected with the intermediate joint.

5. The isolating packer of claim 1, wherein, The expansion rubber sleeve assembly comprises a lower rubberizing cylinder mandrel, the upper end of the lower rubberizing cylinder mandrel is fixedly connected with the outer side of the intermediate joint, the lower rubberizing cylinder mandrel and the lower central pipe form the second annular space, the lower rubberizing cylinder mandrel is externally sleeved with an expansion rubber sleeve, the expansion rubber sleeve is used for sealing by self-expansion, the expansion rubber sleeve is limited between the intermediate joint and the switch assembly, and the lower end of the lower rubberizing cylinder mandrel is connected with the switch assembly.

6. The isolated packer of claim 5, wherein, The expansion rubber sleeve comprises an expansion rubber sleeve body, the expansion rubber sleeve body is provided with expansion metal, the expansion metal can drive the expansion rubber sleeve body to expand by self-expansion, and the outer surface of the expansion rubber sleeve body is provided with a soluble layer. The upper end of the expansion rubber sleeve body and the lower end of the expansion rubber sleeve body are respectively provided with a limiting ring.

7. The isolating packer of claim 5, wherein, The lower ends of the lower central pipe and the lower rubberizing cylinder mandrel are connected with the switch assembly through an intermediate short section, the intermediate short section is provided with a third annular space, and the third annular space is communicated with the second annular space and the flow channel of the switch assembly.

8. The isolating packer of claim 7, wherein, The intermediate short section comprises a connecting mandrel and an outer cylinder, the lower end of the lower central tube is sealingly connected with the inner wall of the connecting mandrel, the lower end of the lower rubber cylinder mandrel is fixedly connected with the outer wall of the connecting mandrel, the outer side of the lower rubber cylinder mandrel is fixedly connected with the upper end of the outer cylinder, the third annular space is formed between the outer cylinder and the connecting mandrel, the first communication hole is arranged on the lower rubber cylinder mandrel between the upper end of the outer cylinder and the upper end of the connecting mandrel, the first communication hole communicates the third annular space and the second annular space, and the outer cylinder and the connecting mandrel are connected with the switch assembly.

9. The isolating packer of claim 8, wherein, The upper end of the upper closing cylinder is fixedly connected with the inner side of the connecting mandrel, the upper end of the connecting sleeve is fixedly connected with the outer side of the connecting mandrel, the lower end of the connecting sleeve is fixedly connected with the upper end of the closing main body, the upper end of the connecting sleeve is fixedly connected with the outer cylinder, and the lower end of the closing main body is fixedly connected with the lower joint. The second communication hole is arranged on the connecting sleeve between the upper end of the connecting sleeve and the lower end of the outer cylinder, and the second communication hole communicates the third annular space and the flow-through channel.

10. The isolating packer of claim 9, wherein, The lower joint comprises a lower outer cylinder, the upper end of the lower outer cylinder is fixedly connected with the lower end of the closing main body, the second bypass hole is arranged on the lower outer cylinder, there is a gap between the lower outer cylinder and the lower closing cylinder, the lower end of the lower outer cylinder and the lower end of the lower closing cylinder are fixedly connected with the lower short section, the lower end of the lower short section is provided with a lower connecting structure, and the lower connecting structure is used for connecting with a pipe column below the lower short section.

11. A sand control string, characterized in that, The isolation packer comprises the isolation packer according to any one of claims 1-10.

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