Thermal expansion pipe inner packer
By designing a packer inside a thermal expansion tube and adopting composite graphite seals and a serrated locking structure, the problem of difficult sealing of packers at high temperatures was solved, enabling multi-stage packing and uniform steam injection for oil production in heavy oil thermal recovery wells, and improving tool accessibility and unsealing reliability.
Patent Information
- Application Number
- CN202421780626.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-25
- Publication Date
- 2025-10-24
- Estimated Expiration
- 2034-07-25
AI Technical Summary
Existing packers are not resistant to high temperatures in downhole conditions of heavy oil thermal recovery wells, making them difficult to seal effectively and difficult to unseal. They are also difficult to pass through a 7-inch screen pipe hanger and be lowered into the test string.
A thermal expansion tube packer was designed, which uses a sealing element made of composite graphite and achieves sealing through a steam thermal expansion mechanism. Combined with a serrated locking structure, it ensures that the sealing element is firmly locked at high temperatures. It has a small outer diameter and a large inner diameter and is suitable for 7-inch screen pipe well completion.
It achieves effective isolation of multiple sections under high temperature conditions, ensuring the uniformity of steam injection and oil production processes, and can smoothly pass through the screen pipe hanger to lower the test tubing string, reducing the risk of tubing string getting stuck.
Smart Images
Figure CN223469249U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model belongs to oilfield exploitation equipment technical field, concretely relates to a heat expansion pipe inner packer. BACKGROUND
[0002] In the process of steam injection and oil production in heavy oil horizontal well thermal recovery development, in order to make horizontal section reservoir even use, by the certain number of packer in the horizontal section screen pipe, with steam distribution valve, production valve cooperation, realize segmented steam injection and oil production. At present, the horizontal section of heavy oil horizontal well is mostly 7-inch screen pipe completion, the inner diameter of screen pipe hanger part is small, the outer diameter of ordinary packer is big, and the packer is difficult to pass through the screen pipe hanger smoothly. The inner diameter of 7-inch screen pipe is big, the heat expansion degree of ordinary packer is small, and it is difficult to effectively set in 7-inch screen pipe. The downhole high temperature of heavy oil thermal recovery well is difficult to seal for a long time, and effective unsealing also has difficulty. Heavy oil horizontal well thermal recovery usually needs to lower the test pipe column in the horizontal section, and the inner diameter of ordinary small diameter packer is small, and the wall thickness is big, which is difficult to lower into the horizontal section and lower the test pipe column in the packer.
[0003] The existing packer mostly adopts pressurization mode setting, and there is the problem of not being resistant to high temperature, not being applicable under the high temperature condition of heavy oil thermal recovery well. UTILITY MODEL CONTENTS
[0004] In view of the problems existing in the prior art, the utility model provides a heat expansion pipe inner packer, and the technical problems to be solved by the utility model are that the structure of the packer is improved, a high-temperature-resistant sealing element is arranged, the packer is applicable to the thermal recovery horizontal well of 7-inch screen pipe completion, and multilayer section sealing, uniform steam injection and oil production under high temperature condition are realized.
[0005] To realize the above object, the utility model adopts the following technical scheme:
[0006] A heat expansion pipe inner packer, comprising a center shaft, an upper joint, an upper cylinder, a sealing element, a lower cylinder and a bottom plug, the upper joint is located at the top end of the center shaft, the upper cylinder, the sealing element and the lower cylinder are sleeved outside the center shaft, the upper joint, the upper cylinder, the sealing element and the lower cylinder are sequentially connected, and the sealing element has a preset temperature-resistant temperature.
[0007] Further, the sealing element is made of composite graphite and has a preset rated temperature-resistant temperature and a limit temperature-resistant temperature.
[0008] Further, the upper cylinder comprises an upper cylinder barrel, a first piston and a first pressure cap, the upper cylinder barrel is sleeved outside the center shaft, both ends of the upper cylinder barrel are connected with the upper joint and the first pressure cap respectively, and the first piston is arranged in the upper cylinder barrel.
[0009] Further, the upper cylinder further comprises a first upper backup cap and a second compression cap, the first upper backup cap and the second compression cap are located in the upper cylinder barrel, and the first upper backup cap, the second compression cap and the upper end of the first piston are sequentially connected.
[0010] Further, the upper cylinder further comprises a second upper backup cap, and the second upper backup cap is connected with the lower end of the first piston.
[0011] Further, the second upper backup cap is connected with the first compression cap through a first shear pin.
[0012] Further, the first compression cap is connected with the upper cylinder barrel through a second shear pin.
[0013] Further, the lower cylinder comprises a lower cylinder barrel, a second piston and a bottom plug, the lower cylinder barrel is sleeved outside the central shaft, the second piston is sleeved in the lower cylinder barrel, and the bottom plug is connected with the bottom end of the lower cylinder barrel.
[0014] Further, the gap between the second piston and the bottom plug in the lower cylinder barrel is filled with expansion liquid.
[0015] Further, the lower cylinder further comprises a third compression cap, and the third compression cap is arranged between the sealing element and the second piston.
[0016] Further, the packer further comprises a rubber tube shaft, and the rubber tube shaft is sleeved between the central shaft and the sealing element.
[0017] Further, the third compression cap is connected with the rubber tube shaft through a third shear pin.
[0018] Further, a lock spring is arranged at the bottom end of the rubber tube shaft, and the lock spring is in contact with the second piston.
[0019] Further, the packer further comprises a lower backup cap, and the lower backup cap is sleeved outside the central shaft and connected with the bottom plug.
[0020] Further, the maximum outer diameter of the packer is 140mm, and the minimum inner diameter is 53mm.
[0021] The working principle of the utility model is as follows:
[0022] 1. When setting the seal, after the packer is connected to the pipeline and lowered to the designed depth, steam is injected into the oil pipe as required. The steam passes through the upper joint and the inner diameter of the central shaft. The heat conduction from the inside to the outside causes the temperature of the packer to rise. The expansion fluid expands due to the heat, pushing the second piston upward and driving the third pressure cap upward. The third shear nail is sheared off. The third pressure cap cooperates with the stationary first pressure cap to compress and expand the seal. The diameter increases to fit and seal on the inner wall of the casing (or screen tube) of the thermal horizontal well, forming a separation seal for the annular space between the casing and the packer, dividing the annular space into two independent spaces. The lock spring is locked on the inner buckle of the second piston by the serrated buckle. The inner and outer teeth mesh with each other, so that the seal cannot return, and the seal forms a permanent seal with the inner diameter of the casing.
[0023] 2. When unsealing, lift the part above the first pressure cap, and the upper joint will move upward with the upper cylinder, the center shaft and the lower cylinder; the seal and the inner diameter of the casing are relatively immobile due to friction, thereby fixing the first upper spare cap, the second pressure cap, the first piston, the first upper spare cap, the first shear pin, the rubber cylinder shaft, the third pressure cap, the third shear pin, the locking spring and the second piston; continue to lift, and the first shear pin will be cut off, and the first pressure cap will be connected to the first piston, leaving space for the seal to deform during unsealing; continue to lift, the seal will be unsealed and deformed, and the upper and lower independent annular spaces separated between the casing and the packer will be connected, and the packer will move upward as a whole, and the unsealing will be completed and lifted out of the well.
[0024] Compared with the prior art, the present invention has the following beneficial effects:
[0025] 1. During steam injection, the expansion agent in the packer expands due to heat, pushing the hydraulic cylinder to drive the pressure cap to compress the seal. The seal is squeezed and expands outward, gradually locking, and ultimately sealing the annular space between the screen and the packer. The seal is made of composite graphite and has a preset rated temperature resistance and a maximum temperature resistance.
[0026] 2. The packer has a small outer diameter and a large inner diameter, which allows it to pass smoothly through the screen hanger and the test string to be lowered into the packer. The large packer diameter makes it suitable for use in horizontal wells and variable-diameter wells. BRIEF DESCRIPTION OF THE DRAWINGS
[0027] Figure 1 This is a schematic diagram of the overall structure of an embodiment of the present utility model.
[0028] The components represented by the reference numbers in the figure are as follows:
[0029] 1 - upper joint, 2 - upper cylinder, 3 - first upper backup cap, 4 - second backup cap, 5 - first piston, 6 - second upper backup cap, 7 - first shear pin, 8 - second shear pin, 9 - first backup cap, 10 - sealing element, 11 - rubber cylinder shaft, 12 - central shaft, 13 - third backup cap, 14 - third shear pin, 15 - lock spring, 16 - second piston, 17 - lower cylinder, 18 - inflation fluid, 19 - bottom plug, 20 - lower backup cap. DETAILED DESCRIPTION
[0030] The technical scheme of the utility model is described clearly and completely below with reference to the drawings.
[0031] Embodiment 1
[0032] As shown in the accompanying drawings, Figure 1 the embodiment provides the following technical scheme:
[0033] A thermal expansion pipe packer, comprising: a central shaft 12, an upper joint 1, an upper cylinder, a sealing element 10, a lower cylinder, the upper joint 1 is located at the top end of the central shaft 12, the upper cylinder, the sealing element 10 and the lower cylinder are sleeved outside the central shaft 12, the upper joint 1, the upper cylinder, the sealing element 10 and the lower cylinder are connected in sequence, and the sealing element 10 has a preset temperature resistance temperature.
[0034] Further, the sealing element 10 is made of composite graphite and has a preset rated temperature resistance temperature and a limit temperature resistance temperature.
[0035] In some preferred embodiments of the embodiment, the rated temperature resistance of the sealing element 10 is 350 DEG C, and the limit temperature resistance is 400 DEG C.
[0036] Further, the upper cylinder comprises an upper cylinder 2, a first piston 5 and a first backup cap 9, the upper cylinder 2 is sleeved outside the central shaft 12, both ends of the upper cylinder 2 are connected with the upper joint 1 and the first backup cap 9 respectively, and the first piston 5 is arranged in the upper cylinder 2.
[0037] Further, the upper cylinder further comprises a first upper backup cap 3 and a second backup cap 4, the first upper backup cap 3 and the second backup cap 4 are located in the upper cylinder 2, and the first upper backup cap 3, the second backup cap 4 and the upper end of the first piston 5 are connected in sequence.
[0038] Further, the upper cylinder further comprises a second upper backup cap 6, and the second upper backup cap 6 is connected with the lower end of the first piston 5.
[0039] Further, the second upper backup cap 6 is connected with the first backup cap 9 through the first shear pin 7.
[0040] Further, the first backup cap 9 is connected with the upper cylinder 2 through the second shear pin 8.
[0041] Further, the lower cylinder comprises a lower cylinder barrel 17 and a second piston 16, the lower cylinder barrel 17 is sleeved outside the central shaft 12, and the second piston 16 is sleeved inside the lower cylinder barrel 17, and the bottom plug 19 is connected with the bottom end of the lower cylinder barrel 17.
[0042] Further, the gap between the second piston 16 and the bottom plug 19 in the lower cylinder barrel 17 is filled with the expansion liquid 18.
[0043] Further, the lower cylinder further comprises a third pressure cap 13, which is arranged between the sealing element 10 and the second piston 16.
[0044] Further, the packer further comprises a rubber tube shaft 11, which is sleeved between the central shaft 12 and the sealing element 10.
[0045] Further, the third pressure cap 13 and the rubber tube shaft 11 are connected through a third shear pin 14.
[0046] Further, the bottom end of the rubber tube shaft 11 is provided with a lock spring 15, which is in contact with the second piston 16.
[0047] Further, the packer further comprises a lower backup cap 20, which is sleeved outside the central shaft 12 and connected with the bottom plug 19.
[0048] Embodiment 2
[0049] The difference from embodiment 1 is that in this embodiment, the hot expansion pipe packer is divided into an unblocking and releasing part, a sealing and locking part, and a setting power part according to functions, wherein:
[0050] The unblocking and releasing part is composed of an upper joint 1, an upper cylinder barrel 2, a first upper backup cap 3, a second pressure cap 4, a first piston 5, a second upper backup cap 6, a first shear pin 7, a second shear pin 8, a first pressure cap 9, and a central shaft 12. The upper joint 1 is threadedly connected with the upper cylinder barrel 2 and the upper end of the central shaft 12, respectively. The second pressure cap 4 is contained between the first upper backup cap 3 and the first piston 5. The first upper backup cap 3 is threadedly connected with the upper end of the first piston 5. The lower end of the upper cylinder barrel 2 is connected with the upper end of the first pressure cap 9 through the second shear pin 8. The upper end of the first pressure cap 9 is connected with the lower end of the first piston 5 through the first shear pin 7. The first piston 5 is slidingly sealed inside the upper cylinder barrel 2. The upper end of the central shaft 12 is slidingly sealed inside the first piston 5.
[0051] The unblocking and releasing part and the part of the oil pipe connected therewith up to the wellhead are also called a pipe string.
[0052] The sealing and locking part consists of a first pressure cap 9, a sealing member 10, a rubber cylinder shaft 11, a central shaft 12, a third pressure cap 13, a third shear pin 14, a locking spring 15, and a second piston 16. The first pressure cap 9, the sealing member 10, and the third pressure cap 13 are sleeved on the outside of the rubber cylinder shaft 11 from top to bottom. The rubber cylinder shaft 11 is sleeved on the outside of the central shaft 12. The locking spring 15 is sleeved on the lower end of the rubber cylinder shaft 11 and locks with the inner lock of the second piston 16. The upper end of the third pressure cap 13 is connected to the lower end of the rubber cylinder shaft 11 by the third shear pin 14.
[0053] In this embodiment, the seal member adopts a composite sealing material, which has a large sealing space after expansion and has the characteristics of high temperature resistance and super wear resistance;
[0054] The sealing locking part adopts a serrated buckle climbing buckle structure. When the lock spring 15 and the lock buckle inside the second piston 16 are forced to climb buckle, the stop position is the locking position, so that the seal is firm.
[0055] The isolation and locking parts can be forcibly released when they are unsealed; when encountering resistance and not unsealing, the pipe string can be thrown away when it is lifted up, and can be unsealed step by step when it is lifted up.
[0056] The setting power section consists of a second piston 16, a lower cylinder 17, an expansion fluid 18, a bottom plug 19, the center shaft 12, and a lower backup cap 20. The second piston 16 is slidingly sealed within the lower cylinder 17 and outside the center shaft 12. The bottom plug 19 is connected and sealed to the lower end of the lower cylinder 17, and the interior of the bottom plug 19 is sealed outside the center shaft 12. The interior and exterior of the lower backup cap 20 are threadedly connected to the interior of the bottom plug 19 and the exterior of the center shaft 12. The second piston 16, lower cylinder 17, bottom plug 19, and center shaft 12 form a sealed hydraulic cylinder, which contains the expansion fluid 18.
[0057] Conventional tools used in 7-inch wells have an outer diameter of 148-152 mm and an inner diameter of about 50 mm;
[0058] The thermal expansion packer in this embodiment has an outer diameter of 140mm and an inner diameter of 53mm. The small outer diameter enhances the tool's maneuverability in horizontal sections, making tripping and lowering the tubing string smoother and less prone to well jamming. The large inner diameter increases the cross-sectional area of the injection channel and reduces the interception area, making injection smoother and reducing tubing loss, making it suitable for use in horizontal wells and variable-diameter wells.
[0059] Example 3
[0060] The difference from the embodiment 2 is that, when the unsealing action is completed, the packer fails to be normally pulled out, the pulling force is increased to pull the pipe string, the upper joint 1 goes up with the upper cylinder 2, the sealing element 10 is not moved relative to the inner diameter of the casing by friction, the first upper backup cap 3, the second compression cap 4, the first piston 5, the second upper backup cap 6, the first shear pin 7, the first compression cap 9, the rubber cylinder shaft 11, the third compression cap 13, the third shear pin 14, the lock spring 15, the second piston 16, the lower cylinder 17, the expansion liquid 18, the bottom plug 19 and the lower backup cap 20 are fixed, the second shear pin 8 is cut by continuously pulling, the upper cylinder 2 is separated from the first compression cap 9, the second compression cap 4 is separated from the inclined surface of the upper joint 1, the upper joint 1 is separated from the connection buckle part of the central shaft 12, the upper joint 1 and the upper cylinder 2 are pulled out of the well by continuously pulling the pipe string, and the other parts of the packer are left in the well, so that the special fishing tool or the female cone is connected with the oil pipe and is lowered into the well to be above the part of the packer left in the well, is lowered while being flushed, and the fishing tool is caught by the first piston 5 after collision, the pipe string is pulled, the first piston 5 drives the first upper backup cap 3, the second compression cap 4, the second upper backup cap 6, the first shear pin 7, the second shear pin 8, the first compression cap 9, the sealing element 10, the rubber cylinder shaft 11, the central shaft 12, the third compression cap 13, the third shear pin 14, the lock spring 15, the second piston 16, the lower cylinder 17, the expansion liquid 18, the bottom plug 19 and the lower backup cap 20 to go up, the remaining part is pulled out of the well, and the secondary fishing is completed.
[0061] When the secondary fishing is performed, the special fishing tool or the female cone is connected with the oil pipe and is lowered into the well to be above the part of the packer left in the well, is lowered while being flushed, and the fishing tool is caught by the first piston 5 after collision, the pipe string is pulled, the first piston 5 drives the first upper backup cap 3, the second compression cap 4, the second upper backup cap 6, the first shear pin 7, the second shear pin 8, the first compression cap 9, the sealing element 10, the rubber cylinder shaft 11, the central shaft 12, the third compression cap 13, the third shear pin 14, the lock spring 15, the second piston 16, the lower cylinder 17, the expansion liquid 18, the bottom plug 19 and the lower backup cap 20 to go up, the remaining part is pulled out of the well, and the secondary fishing is completed.
[0062] The preferred embodiments are only used for limiting the utility model, and various changes and variations can be made by the person skilled in the art. Any modification, equivalent replacement, improvement and the like within the spirit and principle of the utility model are included in the protection scope of the utility model.
Claims
1. A heat-expandable tubular packer, characterized by, The packer comprises a central shaft, an upper joint, an upper cylinder, a sealing element, a lower cylinder, a bottom plug, the upper joint is located at the top end of the central shaft, the upper cylinder, the sealing element and the lower cylinder are sleeved outside the central shaft, the upper joint, the upper cylinder, the sealing element and the lower cylinder are sequentially connected, the sealing element has a preset temperature resistance, the sealing element is made of composite graphite and has a preset rated temperature resistance and a limit temperature resistance; The upper cylinder comprises an upper cylinder barrel, a first piston and a first pressure cap, the upper cylinder barrel is sleeved outside the central shaft, two ends of the upper cylinder barrel are connected with the upper joint and the first pressure cap respectively, and the first piston is arranged in the upper cylinder barrel; The upper cylinder further comprises a first upper backup cap and a second pressure cap, the first upper backup cap and the second pressure cap are located in the upper cylinder barrel, and the first upper backup cap, the second pressure cap and the upper end of the first piston are sequentially connected; The lower cylinder comprises a lower cylinder barrel, a second piston and a bottom plug, the lower cylinder barrel is sleeved outside the central shaft, the second piston is sleeved in the lower cylinder barrel, and the bottom plug is connected with the bottom end of the lower cylinder barrel; The lower cylinder further comprises a third pressure cap, the third pressure cap is arranged between the sealing element and the second piston. The packer further comprises a rubber sleeve shaft, the rubber sleeve shaft is sleeved between the central shaft and the sealing element, and a lock spring is arranged at the bottom end of the rubber sleeve shaft and in contact with the second piston. The upper cylinder further comprises a second upper backup cap, the second upper backup cap is connected with the lower end of the first piston.
2. The heat-expandable tubular packer of claim 1, wherein: The second upper backup cap and the first pressure cap are connected through a first shear pin.
3. The heat-expandable tubular packer of claim 1, wherein: The first pressure cap and the upper cylinder barrel are connected through a second shear pin.
4. The heat-expandable tubular packer of claim 1, wherein: The gap between the second piston and the bottom plug in the lower cylinder barrel is filled with expansion liquid.
5. The heat-expandable tubular packer of claim 1, wherein: The third pressure cap and the rubber sleeve shaft are connected through a third shear pin.
6. The heat-expandable tubular packer of claim 1, wherein: The packer further comprises a lower backup cap, the lower backup cap is sleeved outside the central shaft and connected with the bottom plug.
7. The heat-expandable tubular packer of claim 1, wherein: The maximum outer diameter of the packer is 140 mm, and the minimum inner diameter is 53 mm.
8. The heat-expandable tubular packer of claim 1, wherein: