Composite rubber packer and horizontal well segmented water-finding string including the packer

Abstract

The present invention relates to a composite rubber sleeve packer and a horizontal well water-finding string including the packer. The packer comprises a central tube and a rubber sleeve upper protective sleeve, a rubber sleeve, a sealing piston and a rubber sleeve lower protective sleeve which are sequentially sleeved on the outer wall of the central tube; the outer wall of the central tube is sleeved with a sealing piston sleeve, which is connected to the rubber sleeve lower protective sleeve; a first gap is formed between the rubber sleeve and the sealing piston sleeve, and the sealing piston can slide relative to the sealing piston sleeve in a dynamic seal; a hydraulic sealing one-way valve is installed in the rubber sleeve upper protective sleeve, the input end of the hydraulic sealing one-way valve is connected to the input through hole, and the output end of the hydraulic sealing one-way valve is connected to the first gap; when the sealing piston slides upward relative to the sealing piston sleeve, the sealing piston compresses the lower end of the rubber sleeve. Its beneficial effects are that the service life and reliability are improved, the locking mechanism is simplified, and the manufacturing and use costs are reduced; the success rate of recovering the horizontal well water-finding string is improved, the water-finding efficiency is improved, and the operation cost is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of oil and gas production in oil and gas fields, and in particular to a composite rubber packer and a horizontal well segmented water-finding string comprising the packer. Background Art

[0002] Horizontal wells are specialized wells with a maximum inclination angle approaching 90° (generally no less than 86°) and maintaining a defined horizontal section within the target formation. Horizontal wells are suitable for thin oil and gas layers or fractured reservoirs, aiming to increase the exposed area of ​​the oil and gas layer. If water is produced during production in a horizontal well, the water-producing layer must be accurately identified. Currently, the most representative method for finding water in horizontal wells is mechanical staged production testing, which typically uses packers to isolate the horizontal section of the horizontal well.

[0003] Most of the existing seals are pushed by a piston mechanism to squeeze and deform the rubber cylinder, expand it outward, and then press it against the inner wall of the production casing to achieve a seat seal. However, because this structure forcibly squeezes the rubber cylinder at one end to deform it, and the rubber cylinder itself requires a certain hardness and strength, this structure has the following disadvantages: 1. The deformation of the rubber cylinder during the extrusion process will be subject to a certain limit, so that the expansion of the rubber cylinder is generally not very large. In this way, even if the outer diameter of the rubber cylinder is smaller than the inner diameter of the production casing, it is only enough to just fit in. In this way, when the seal is placed in the production casing, it is inevitable that the rubber cylinder will often touch the wall of the production casing, which will affect the work progress. Secondly, the frequent friction between the rubber cylinder and the inner wall of the production casing will affect the service life of the rubber cylinder and the reliability of the seal; 2. The expansion of the rubber cylinder is limited, resulting in the diameter design of the entire packer needing to adapt to the rubber cylinder, which will cause the diameter of the entire packer to be too large, which not only increases the manufacturing cost, but also makes it difficult to inject liquid into the piston. During extrusion, the amount of liquid injected into the central tube is too large, which is not conducive to energy saving and high efficiency; 3. Because the entire rubber cylinder expansion process depends entirely on piston extrusion, the driving force is to push the piston first, and the piston then pushes the rubber cylinder to deform. During the entire indirect pushing process, the piston mechanism also needs to overcome friction and other resistances. In addition, the hardness of the rubber cylinder itself causes more force to be lost during the extrusion process, which requires a larger thrust and a longer extrusion time, affecting work efficiency; 4. After the piston mechanism squeezes the rubber cylinder, it needs to maintain the expanded state of the rubber cylinder. This requires a very reliable locking device to fix the piston mechanism. This locking device will also withstand a large reverse thrust. If the locking mechanism is not reliable enough, the rubber cylinder will inevitably shrink and deform, affecting the sealing effect of the rubber cylinder, and even causing the sealing to fail. Therefore, the structure of the locking device in the current packer is very complicated, which greatly increases the manufacturing and use costs; 5. The sealing and unsealing process of the existing packer is complicated, which will also affect work efficiency.

[0004] Therefore, there is an urgent need to provide a reliable, energy-saving, efficient, simple in structure, simple in operation and relatively low-cost packer and a horizontal well segmented water-finding string including the packer. Summary of the Invention

[0005] (1) Technical issues to be resolved

[0006] In view of the above-mentioned shortcomings and deficiencies of the prior art, the present invention provides a composite rubber cartridge packer and a horizontal well segmented water-finding pipe string including the packer, which solves the problems of the existing packers such as greatly affected reliability, disadvantageous for energy saving, low working efficiency, complex structure, cumbersome operation and relatively high cost.

[0007] (2) Technical solution

[0008] In order to achieve the above objectives, the main technical solutions adopted by the present invention include:

[0009] In the first aspect, the present invention provides a composite rubber-sleeved seal for being lowered into a production casing, wherein the seal comprises a center tube and an upper rubber-sleeved protective sleeve, a rubber tube, a sealing piston and a lower rubber-sleeved protective sleeve which are sequentially sleeved on the outer wall of the center tube; the upper end of the rubber tube is connected to the upper rubber-sleeved protective sleeve, and the lower end is connected to the sealing piston, and the diameter of the rubber tube in a non-expanded state is smaller than the inner diameter of the production casing; the lower end of the sealing piston is located in the cavity of the lower rubber-sleeved protective sleeve, and a hydraulic cavity for liquid injection is formed between the sealing piston and the lower rubber-sleeved protective sleeve; the sealing piston, the sealing piston, the sealing piston, the sealing piston, the side wall of the center tube is also provided with a liquid injection through hole which can be connected to the hydraulic cavity, and the outer wall of the center tube is also sleeved with a sealing piston sleeve, and the center tube can be relatively The sealing piston sleeve slides in a dynamic seal with the seat sealing piston sleeve; the sealing piston sleeve is located between the upper protective sleeve of the rubber cylinder and the lower protective sleeve of the rubber cylinder, and the sealing piston sleeve is connected to the lower protective sleeve of the rubber cylinder; the rubber cylinder and the sealing piston sleeve are arranged outside the sealing piston sleeve; a first gap is formed between the rubber cylinder and the sealing piston sleeve; the sealing piston can slide in a dynamic seal relative to the sealing piston sleeve; when the sealing piston slides upward relative to the sealing piston sleeve, the sealing piston compresses the lower end of the rubber cylinder; the upper protective sleeve of the rubber cylinder is fixedly connected to the outside of the center tube; a hydraulic seat sealing one-way valve is installed in the upper protective sleeve of the rubber cylinder, the input end of the hydraulic seat sealing one-way valve is connected to the input through hole located on the side wall of the center tube, and the output end of the hydraulic seat sealing one-way valve is connected to the first gap.

[0010] The composite rubber cartridge packer proposed in the embodiment of the present invention adopts a method of hydraulic filling and expansion combined with the pushing of the sealing piston, which greatly increases the expansion amount of the rubber cartridge, and its expansion amount can reach 2-3 times that of the existing technology, which can achieve the following effects: 1. The outer diameter of the rubber cartridge can be made smaller, that is, much smaller than the inner diameter of the production casing, so that the probability of the entire packer touching the production casing wall during the placement of the production casing is greatly reduced, so that it will not affect the work progress, and the service life of the rubber cartridge will not be affected due to frequent friction between the rubber cartridge and the inner wall of the production casing, thereby making the use of the rubber cartridge in the present invention Reliability is greatly increased; 2. Because the expansion amount of the rubber cylinder in the present invention can reach 2-3 times that of the existing technology, the diameter of the entire composite rubber cylinder packer of the present invention can be smaller than that of the existing technology, thereby saving costs and improving injection efficiency, which is conducive to high efficiency and energy saving; 3. The present invention adopts the method of hydraulic filling and expansion combined with the pushing of the seat seal piston to relatively reduce the hardness requirement of the rubber cylinder itself, which can greatly reduce the thrust required by the seat seal piston, and during the entire expansion process, the seat seal piston pushes the rubber cylinder to deform, causing the gap between the rubber cylinder and the seat seal piston sleeve to instantly increase, and then the The gap is quickly filled with high-pressure liquid, reducing the resistance to liquid filling. After the initial hydraulic filling, the rubber sleeve is also deformed, quickly creating a compression guide for the sealing piston, avoiding the sealing piston from directly squeezing the rubber sleeve from a flat state, which consumes a certain amount of thrust and squeezing time. The rubber sleeve is then quickly expanded to complete the sealing. Throughout the entire process, the sealing piston is no longer the only structure that plays a major driving role, greatly improving work efficiency. Moreover, the entire expansion process is efficient and rapid because both the hydraulic filling directly acts on the rubber sleeve and the sealing piston assists in pushing. During the entire sealing process, even if the deformation of the rubber sleeve is much greater than that of the existing technology, the entire sealing time is only about 1 / 2 to 1 times that of the existing technology, thereby improving work efficiency. 4. After the rubber sleeve is expanded and sealed, its ability to maintain the expanded state is greatly improved because it is internally hydraulically expanded. This not only greatly reduces the probability of sealing failure, but also greatly reduces the strength requirements of the locking mechanism of the sealing piston. It only needs to adopt any existing simple locking structure, and in some scenarios, the locking mechanism may not even be required. This greatly simplifies the structure of the entire composite rubber sleeve packer and reduces manufacturing and use costs. 5. When unlocking the seat seal of the present invention, it is only necessary to pull the center tube to complete the unlocking, which is very convenient and quick.

[0011] Optionally, in the initial state, the upper protective sleeve of the rubber cylinder can seamlessly fit over the upper end of the sealing piston sleeve. This reduces the injection volume, improves work efficiency, and also reduces the liquid pressure on the upper protective sleeve of the rubber cylinder, alleviating the burden on components. When the center tube slides upward relative to the sealing piston sleeve, a second gap is formed between the upper protective sleeve of the rubber cylinder and the upper end of the sealing piston sleeve. The second gap connects to the first gap. This second gap is primarily intended to more quickly transfer liquid from the first gap to the second gap, thereby efficiently completing the recovery and unsealing of the rubber cylinder.

[0012] Optionally, the sealer also includes a first temporary stop structure, which can temporarily prevent the center tube from moving relative to the sealing piston sleeve; the first temporary stop structure is a first unsealing pin arranged between the center tube and the sealing piston sleeve and capable of being sheared off, and / or a first unsealing pin arranged between the center tube and the protective sleeve under the rubber cylinder and capable of being sheared off; when unlocking, the first unsealing pin can be sheared off by pulling the center tube to complete the unlocking, and the operation is convenient and quick.

[0013] Optionally, the packer further includes a second temporary stop structure that temporarily prevents the sealing piston from moving relative to the sealing piston sleeve, preventing relative movement between the sealing piston and the sealing piston sleeve due to improper operation. The second temporary stop structure comprises a second unsealing pin disposed between the sealing piston and the sealing piston sleeve and capable of shearing, and / or a second unsealing pin disposed between the sealing piston and the lower protective sleeve of the rubber cylinder and capable of shearing. During unlocking, the second unsealing pin can be directly sheared off as the sealing piston moves, completing the unlocking process, providing a convenient and quick operation.

[0014] Optionally, the sealing piston sleeve is provided with a piston sleeve drainage hole communicating with the first gap, and the side wall of the center tube is provided with a center tube drainage hole. The center tube can be moved relative to the sealing piston sleeve until the center tube drainage hole is aligned with the piston sleeve drainage hole, thereby draining liquid between the rubber cylinder and the sealing piston sleeve. A first dissolvable locking device is provided between the piston sleeve drainage hole and the outer wall of the center tube. Before unlocking, the first dissolvable locking device can further limit the movement between the sealing piston sleeve and the center tube. During unlocking, the first dissolvable locking device dissolves in the presence of liquid, completing the unlocking and simultaneously opening the piston sleeve drainage hole.

[0015] Optionally, the setting piston sleeve is provided with a deblocking liquid-permeable through-hole, and a second dissolvable locking device is disposed between the deblocking liquid-permeable through-hole and the outer wall of the center tube. The setting piston is provided with a piston liquid-permeable hole, and the setting piston can be moved relative to the setting piston sleeve until the piston liquid-permeable hole aligns with the deblocking liquid-permeable through-hole, thereby introducing deblocking liquid. This second dissolvable locking device can further limit relative movement between the setting piston sleeve and the center tube before unlocking. During unlocking, the second dissolvable locking device dissolves in the liquid, completing unlocking.

[0016] Optionally, when the sealing piston slides to the limit position, a temporary locking mechanism can be used to limit the relative sliding between the sealing piston and the sealing piston sleeve, thereby helping to increase the sealing effect.

[0017] Optionally, the inner wall of the sealing piston sleeve and / or the inner wall of the lower protective sleeve of the rubber cartridge are provided with a stepped surface, and the outer wall of the central tube is provided with a boss. When the central tube moves to the extreme position, the boss engages with the stepped surface, further facilitating the release of the sealing and the smooth removal of the entire composite rubber cartridge packer.

[0018] Optionally, a load-bearing fixed automatic unlocking mechanism is also included; the load-bearing fixed automatic unlocking mechanism includes a load-bearing positioning column, the inner end of which passes through the through hole on the sealing piston sleeve and extends into the load-bearing positioning hole on the outer wall of the center tube, and a top spring is provided in the load-bearing positioning hole; when in the locked state, the upper end of the load-bearing positioning column is squeezed by the composite rubber cylinder or the sealing piston to be flush with the outer wall of the sealing piston sleeve, so that the lower end of the load-bearing positioning column compresses the top spring; the inner wall of the sealing piston is provided with a variable diameter cavity that can accommodate the upper end of the load-bearing positioning column when the sealing piston moves. This load-bearing fixed automatic unlocking mechanism can withstand a large load and has a higher strength to prevent the center tube from moving relative to the sealing piston sleeve due to misoperation and affecting the operation.

[0019] In a second aspect, the present invention further provides a horizontal well segmented water-finding string, which includes the aforementioned composite rubber packer. The rear end of the water-finding string is provided with a guide, the upper end of the guide being connected to the lower section of the perforated circulation sub, the upper end of the perforated circulation sub being connected to the lower end of the packer seat ball seat, the upper end of the packer seat ball seat being connected to the composite rubber packer. There are multiple composite rubber packers, which are connected end to end by oil tubing. A unidirectional flow tracer sub corresponding to the horizontal well perforation section is provided on the oil tubing at the lower end of each composite rubber packer. The horizontal well segmented water-finding string can be lowered into the entire horizontal section of the production casing at one time, and normal production can be basically maintained during the water-finding process, eliminating the need for expensive continuous oil tubing equipment and reducing operating costs.

[0020] (3) Beneficial effects:

[0021] The beneficial effects of the present invention are:

[0022] 1. The composite rubber cartridge packer proposed in the present invention has a rubber cartridge deformation variable that is much larger than that in the prior art, and its deformation variable can be equivalent to 2 to 3 times that of the prior art rubber cartridge. The effect brought about is: the outer diameter of the rubber cartridge of the present invention can be much smaller than the inner diameter of the production casing compared with the prior art rubber cartridge, and it can be easily inserted into the production casing of the horizontal well, greatly reducing the probability of the rubber cartridge touching and rubbing against the inner wall of the production casing, ensuring the work progress while improving the service life and reliability of the composite rubber cartridge packer; under normal circumstances, the outer diameter of the rubber cartridge of the present invention can be at least 10 mm smaller than the outer diameter of the rubber cartridge upper protective sleeve and the rubber cartridge lower protective sleeve, and the outer diameter of the rubber cartridge upper protective sleeve and the rubber cartridge lower protective sleeve is at least 10 mm smaller than the inner diameter of the production casing, and the diameter change is obvious.

[0023] 2. The composite rubber tube packer proposed in the present invention can reduce the diameter of the entire composite rubber tube packer due to the increased expansion of the rubber tube. Compared with the existing technology, it not only saves costs, but also allows a smaller diameter to achieve a pressurization effect during injection, thereby improving efficiency and facilitating high efficiency and energy saving.

[0024] 3. The composite rubber cartridge packer proposed in the present invention adopts the dual force of direct hydraulic injection into the rubber cartridge and the pushing of the sealing piston. On the one hand, the direct hydraulic filling method is simple and direct, which reduces the force required for expansion during the intermediate process. On the other hand, because the expansion amount of the rubber cartridge is significantly increased compared with the existing technology, its hardness requirement is also lower than that of the rubber cartridge in the existing technology. In this way, the thrust required for the sealing piston is also greatly reduced accordingly. In addition to the force of hydraulic expansion, the two forces cooperate. During the entire expansion process, the sealing piston pushes the rubber cartridge to deform, causing the gap between the rubber cartridge and the sealing piston sleeve to instantly increase. After that, the gap is quickly filled with high-pressure liquid, which quickly reduces the resistance to liquid filling. After the rubber cylinder is hydraulically filled, it is also deformed rapidly, which quickly generates a compression guide for the sealing piston, saving the thrust and extrusion time consumed when the sealing piston directly and forcibly squeezes the rubber cylinder from a flat state, and then quickly expands the rubber cylinder to complete the sealing. Moreover, compared with the prior art, the rubber cylinder of the present invention has hydraulic filling, which greatly reduces the reverse thrust of the rubber cylinder on the sealing piston, saving the thrust of the sealing piston. In the present invention, the hydraulic expansion and the sealing piston complement each other. When the rubber cylinder of the present invention satisfies the condition that the deformation variable is 2 to 3 times that of the existing rubber cylinder and the filling parameters are the same, its expansion time is only about 1 / 2 to 1 times that of the existing rubber cylinder, and the effect is significant.

[0025] 4. The composite rubber tube packer proposed in the present invention has a greatly improved ability to maintain the expanded state because its interior is hydraulically expanded after the rubber tube is expanded to complete the seat seal. This not only greatly reduces the probability of seat seal failure, but also greatly reduces the strength requirement for the locking mechanism of the seat seal piston. It only needs to adopt any existing simple locking structure, and even in some scenarios, the locking mechanism may not be required, which greatly simplifies the structure of the entire composite rubber tube packer and reduces the manufacturing and use costs.

[0026] 5. The composite rubber-tube packer proposed in the present invention can unlock the seat seal by simply pulling the central tube, which is very convenient and quick, and improves the success rate of recovering the water-finding string in horizontal wells.

[0027] In addition, the horizontal well segmented water-finding string of the present invention can be lowered into the entire horizontal section of the production casing at one time, and normal production can be basically maintained during the water-finding process without the need for expensive continuous tubing equipment, thereby reducing operating costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is an overall schematic diagram of a water-finding string for installing the composite rubber packer of the present invention;

[0029] Figure 2 This is a schematic diagram of the initial state of the composite rubber packer of the present invention entering the well;

[0030] Figure 3 This is a schematic diagram of the composite rubber packer of the present invention when the filling and seating are initially completed (the load-bearing positioning column is ready to extend into the variable diameter cavity of the seating piston);

[0031] Figure 4 This is a schematic diagram of the composite rubber packer of the present invention when the filling and seating are initially completed (the load-bearing positioning column has extended into the variable diameter cavity of the seating piston);

[0032] Figure 5 This is a schematic diagram of the composite rubber packer of the present invention being released from the well;

[0033] Figure 6 This is a partial enlarged view of the load-bearing positioning column;

[0034] Figure 7 A schematic diagram of a state before locking of a temporary locking mechanism of a sealing piston;

[0035] Figure 8 for Figure 7 A schematic diagram of the temporary locking mechanism after locking is shown;

[0036] Figure 9 A schematic diagram of another form of a temporary locking mechanism of the sealing piston before locking;

[0037] Figure 10 for Figure 9 Schematic diagram of the temporary locking mechanism after locking.

[0038] [Description of Reference Numerals]

[0039] 1. Guide; 2. Opening circulation sub; 3. Packer seat and ball seat; 4. Differential pressure sleeve; 5. Perforating section; 6. One-way flow tracer sub; 7. Composite rubber packer; 8. Safety joint; 9. Surface wellhead; 10. Tubing; 11. Production casing; 12. Center pipe; 121. Input hole; 122. Center pipe drainage hole; 123. Liquid injection hole; 124. First boss; 125. Load-bearing positioning hole; 1251. Ejection spring; 126. Second boss; 127. Lock tongue cavity; 128. Lock tongue; 129. Lock tongue ejection spring; 13. Rubber cartridge connector; 14. Seat seal piston sleeve; 141. Piston sleeve drainage hole. 142. Unsealing liquid-permeable through hole; 143. Piston sleeve stepped surface; 144. Locking chamber; 1441. Locking barb; 15. Hydraulic seat seal one-way valve; 16. Load-bearing positioning column; 171. First soluble locking device; 172. Second soluble locking device; 181. Upper protective sleeve of rubber cylinder; 182. Lower protective sleeve of rubber cylinder; 1821. Hydraulic cavity; 1822. Lower protective sleeve stepped surface; 1823. Lower protective sleeve through hole; 19. Lower end joint; 20. First unsealing pin; 21. Rubber cylinder; 23. Sealing piston; 231. Piston liquid-permeable hole; 232. Variable diameter chamber; 233. Locking hole; 234. Elastic barb lock card; 24. Second unsealing pin. DETAILED DESCRIPTION

[0040] In order to better explain the present invention and facilitate understanding, the present invention is described in detail below with reference to the accompanying drawings and through specific embodiments. Figures 1 to 5 With reference to the orientation of , along the axial direction of the central pipe 12 , the side away from the surface wellhead 9 is defined as “lower”, and the side close to the surface wellhead 9 is defined as “upper”.

[0041] The embodiment of the present invention proposes a composite rubber-tube packer and a horizontal well segmented water-finding string, which solve the problems of existing packers such as significant reliability impact, disadvantageous energy conservation, low work efficiency, complex structure, cumbersome operation and relatively high cost. The composite rubber-tube packer is used to be lowered into the production casing. The packer includes a center tube and a rubber-tube upper protective sleeve, a rubber tube, a sealing piston and a rubber-tube lower protective sleeve sequentially sleeved on the outer wall of the center tube; the outer wall of the center tube is also sleeved with a sealing piston sleeve, which is connected to the rubber-tube lower protective sleeve; a first gap is formed between the rubber tube and the sealing piston sleeve, and the sealing piston can slide relative to the sealing piston sleeve in a dynamic seal; a hydraulic sealing one-way valve is installed in the rubber-tube upper protective sleeve, the input end of the hydraulic sealing one-way valve is connected to the input through hole, and the output end of the hydraulic sealing one-way valve is connected to the first gap; when the sealing piston slides upward relative to the sealing piston sleeve, the sealing piston compresses the lower end of the rubber tube. The present invention achieves sealing by compressing the sealing piston and squeezing the rubber cylinder with liquid in the inner cavity, causing it to expand, and can achieve the purpose of step-by-step unsealing and forced recovery of the rubber cylinder by lifting the top end of the rubber cylinder and discharging the liquid through the drainage hole inside the center tube. It can achieve the sealing of each layer of the horizontal well, and because the diameter of the rubber cylinder is much smaller than the inner diameter of the production casing, the water-finding pipe string can be easily lowered into the horizontal well, ensuring the work progress while improving the service life and reliability of the composite rubber cylinder sealer. At the same time, the smaller diameter not only saves costs, but also can be exchanged for a pressurization effect, which is conducive to high efficiency and energy saving, and the locking mechanism is simplified, reducing manufacturing and use costs. In addition, the sealing of the present invention is simple and can be unsealed step by step, which improves the success rate of horizontal well water-finding pipe string recovery, improves water-finding efficiency, and reduces operating costs. Furthermore, the horizontal well segmented water-finding pipe string of the present invention can be lowered into the entire horizontal section of the production casing at one time, and normal production can still be basically maintained during the water-finding process. There is no need to use expensive continuous oil pipe equipment, which reduces operating costs.

[0042] To better understand the above technical solutions, exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments described herein. Instead, these embodiments are provided to enable a clearer and more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.

[0043] Example:

[0044] Reference Figure 1 and Figure 2An embodiment of the present invention provides a composite rubber-sleeved packer for being lowered into a production casing 11. The packer comprises a central tube 12 and a rubber-sleeved upper protective sleeve 181, a rubber-sleeved tube 21, a sealing piston 23, and a rubber-sleeved lower protective sleeve 182, which are sequentially sleeved on the outside of the central tube 12. The diameter of the rubber-sleeved tube 21 in its non-expanded state is smaller than the inner diameter of the production casing 11. The rubber-sleeved upper protective sleeve 181 is connected to the upper end of the rubber-sleeved tube 21, and the lower end of the rubber-sleeved tube 21 is connected to the upper end of the sealing piston 23. The lower end of the sealing piston 23 is located in the cavity of the rubber-sleeved lower protective sleeve 182, and a hydraulic cavity 1821 for liquid injection is formed between the rubber-sleeved lower protective sleeve 182 and the rubber-sleeved lower protective sleeve 182. The side wall of the central tube 12 is further provided with a liquid injection through-hole 123 that can communicate with the hydraulic cavity 1821. The outer wall of the central tube 12 is further sleeved with a sealing piston sleeve 14, and the central tube 12 can slide relative to the sealing piston sleeve 14 in a dynamic seal. The sealing piston sleeve 14 is located between the upper and lower protective sleeves 181 and 182 of the rubber cylinder, and is connected to the latter. The rubber cylinder 21 and the sealing piston 23 are sleeved outside the sealing piston sleeve 14. A first gap is formed between the rubber cylinder 21 and the sealing piston sleeve 14. The sealing piston 23 can slide relative to the sealing piston sleeve 14 in a dynamic sealing manner. When the sealing piston slides upward relative to the sealing piston sleeve, it compresses the lower end of the rubber cylinder.

[0045] The upper protective sleeve 181 of the rubber sleeve is fixedly connected to the exterior of the central tube 12. A hydraulically seated one-way valve 15 is installed within the upper protective sleeve 181. The input end of the hydraulically seated one-way valve 15 communicates with the input through-hole 121 located on the side wall of the central tube 12, and the output end of the hydraulically seated one-way valve 15 communicates with the first gap.

[0046] During construction, multiple composite rubber packers are connected end-to-end to form a horizontal well segmented water-finding string. Adjacent composite rubber packers are connected end-to-end via tubing. Specifically, the lower end of each composite rubber packer is connected to the upper end of the center tube 12 of the next composite rubber packer. The lower end of the lowest composite rubber packer is connected to a differential pressure sleeve 4, which is connected to a packer seat ball seat 3, which is connected to a perforation sub 2, which is connected to a guide 1. A unidirectional flow tracer sub 6 is installed on the tubing below each composite rubber packer 7, corresponding to the horizontal well perforation section 5. The unidirectional flow tracer sub 6 features unidirectional flow, allowing fluid to flow into the sub through the outer wall, while preventing fluid from flowing out through the inner wall. The differential pressure sleeve can be opened by internal pressure injection, establishing a flow channel inside and outside the water-finding string. The open hole circulation sub is used to perform sand flushing on the production casing.

[0047] The connection between the lower end of the above-mentioned composite rubber tube packer and the upper end of the central tube 12 of the next composite rubber tube packer can be that the lower end of the rubber tube lower protective sleeve 182 of the composite rubber tube packer is directly connected to the upper end of the central tube 12 of the next composite rubber tube packer, or a lower end joint 19 can be connected to the lower end of the rubber tube lower protective sleeve 182, and connected to the upper end of the central tube 12 of the next composite rubber tube packer through the lower end joint 19.

[0048] Going down the well, refer to Figure 1 The construction of an oil or gas well begins by drilling a wellbore from the surface, then lowering a production casing 11 into the wellbore. Finally, cement is injected into the annular space between the production casing 11 and the wellbore for cementing. After cementing is complete, a perforating gun is detonated in the target formation to form a horizontal well perforation section 5, or the sliding sleeve is opened by pressurizing the interior of the production casing 11, establishing a fracturing channel. Formation fluids can enter the production casing 11 through the horizontal well perforation section or sliding sleeve. Formation fluids primarily include oil, gas, and water.

[0049] The above-mentioned horizontal well segmented water-finding string is detachably connected to the oil pipe 10 through the safety joint 8, that is, the upper end of the central tube of the composite rubber packer at the top of the horizontal well segmented water-finding string is detachably connected to the oil pipe 10 through the safety joint 8. The safety joint 8 is a commonly used detachable joint. By adopting a detachable connection method, when the water-finding string encounters an unexpected situation during operation, it can be urgently released and the oil pipe 10 can be pulled out to free up a passage, which is convenient for the salvage of downhole tools and the handling of subsequent accidents, effectively reducing operational risks and economic losses. Generally, the inner diameter of the safety joint is larger than the inner diameter of the lower string tool, and it can be separated from the lower string by throwing a ball. It belongs to the existing technology and will not be described in detail.

[0050] After the horizontal well segmented water finding string is connected to the oil pipe 10, it is lowered to the Figure 1 The designated design position shown. During the well entry process, because the expansion amount of the rubber cylinder 21 is much greater than that of the rubber cylinder in the prior art, the inner diameter of the entire composite rubber cylinder packer of the present invention can be designed to be smaller, and the diameter of the rubber cylinder 21 is also much smaller than the production casing 11. Therefore, during the well entry process, the probability of collision and friction between the rubber cylinder 21 and the inner wall of the production casing 11 is greatly reduced, which improves the construction efficiency and increases the service life of the rubber cylinder 21. After the entire horizontal well segmented water-finding string is in place, the horizontal well segmented water-finding string can realize the function of reverse sand flushing treatment of the production casing 11 through the hole-opening circulation short section 2, and use high-speed flowing liquid to disperse the sand at the bottom of the well, and use the circulation capacity of the liquid flow to bring the dispersed sand out of the ground, thereby clearing the sand accumulated at the bottom of the well and restoring and improving the production of the well.

[0051] At this time, the status of the composite rubber packer is as follows: Figure 2When a seal is required, a packer sealing ball is dropped into the wellhead and pumped to the packer sealing ball seat 3, forming a closed high-pressure environment inside the horizontal well segmented water-finding string. The liquid is driven by high pressure. On the one hand, the high-pressure liquid enters the hydraulic cavity 1821 through the liquid injection hole 123, pushing the sealing piston 23 to move upward, compressing and pushing the lower end of the rubber cylinder 21. On the other hand, the high-pressure liquid enters the gap between the rubber cylinder 21 and the sealing piston sleeve 14 through the input hole 121 and the hydraulic sealing one-way valve 15, expanding the rubber cylinder to achieve sealing. During the entire sealing process, the sealing piston 23 and the hydraulic charging rubber cylinder 21 work together, and the two complement each other. On the one hand, the direct hydraulic charging method is simple and direct, which reduces the force required for expansion in the intermediate process. On the other hand, because the expansion amount of the rubber cylinder is significantly increased compared with the existing technology, its hardness requirement is also lower than that of the rubber cylinder in the existing technology. In this way, the thrust required by the sealing piston will also be greatly reduced accordingly. In addition to the force of hydraulic expansion, the two forces cooperate. During the entire expansion process, the sealing piston pushes the rubber cylinder to deform, causing the gap between the rubber cylinder and the sealing piston sleeve to instantly increase. After that, the gap is quickly filled with high-pressure liquid, which quickly reduces the resistance to liquid filling. After the hydraulic filling, the rubber cylinder also causes the rubber cylinder to deform quickly, quickly generating a compression guide for the sealing piston, saving the thrust and extrusion time consumed when the sealing piston directly and forcibly squeezes the rubber cylinder from a flat state, and then quickly expanding the rubber cylinder to complete the sealing. That is, as we usually understand, compressing a curved object is more time-saving and labor-saving than compressing a straight object. Moreover, compared with the prior art, in the prior art, when the piston squeezes the rubber cylinder, the rubber cylinder will always have a large reverse thrust on the piston, affecting the expansion efficiency and time. However, since the rubber cylinder of the present invention is hydraulically filled, the reverse thrust of the rubber cylinder on the sealing piston will be greatly reduced, saving the thrust of the sealing piston and improving the expansion efficiency and time.

[0052] The hydraulic expansion and seating pistons in the present invention truly complement each other. When the deformation of the rubber cylinder in the present invention is 2 to 3 times that of the existing rubber cylinder and the filling parameters are the same, its expansion time is only about 1 / 2 to 1 times that of the existing rubber cylinder.

[0053] The state of the composite rubber packer 7 completing the sealing is shown in FIG. Figure 3 and Figure 4After the composite rubber packer 7 of the present invention is sealed in the horizontal well segmented water-finding string, conventional pumping operations or oil pumps used in oil and gas field development can be used in the vertical well section of the oil pipe for normal production. The perforation section 5 is isolated by the composite rubber packer 7 at the upper and lower ends. The output fluid of the perforation section 5 can only enter the interior of the horizontal well segmented water-finding string through the one-way flow tracer short section 6, and finally go up through the oil pipe 10 to the wellhead 9 to reach the ground. In this process, the output fluid in the perforation section 5 will simultaneously carry the different types of tracers deployed on the one-way flow tracer short section back to the ground. After the tracer analysis of the output fluid on the ground, it can be confirmed which layer is producing water, making technical preparations for subsequent horizontal well water plugging operations. It is convenient and easy to use on site and saves costs.

[0054] In addition, the sampler is installed on the inner wall of the horizontal well segmented water-finding string. Under the control of the control module, the sampler samples and stores the fluid in the water-finding string. As the horizontal well segmented water-finding string is pulled out to the ground, the fluid in the sampler can be taken out.

[0055] A horizontal well segmented water-finding string using the composite rubber-tube packer of the present invention is provided. By installing a flow meter on the inner wall of the horizontal well segmented water-finding string, the flow meter can measure the flow of different production intervals under the control of a control module, and can be compared and confirmed with the analysis results of the tracer production fluid.

[0056] After completing the water-finding operation within the set time, the horizontal well segmented water-finding string is lifted as a whole. The composite rubber packer is unsealed step by step during the string lifting process, and then the entire horizontal well segmented water-finding string can be recovered to the surface. Figure 5 , pull the center tube 12 upwards, refer to Figure 5 In the direction of the horizontal arrow, the central tube 12 slides upward relative to the sealing piston sleeve, causing the rubber cylinder 21 to gradually retract, completing the unsealing.

[0057] The horizontal well segmented water-finding string using the composite rubber-tube packer of the present invention can be lowered into the entire horizontal section at one time, and normal production can be basically maintained during the water-finding process, without the need for expensive continuous tubing equipment, thereby reducing operating costs.

[0058] See also Figure 2 and Figure 4, further preferred for the above embodiment, in the initial state, the protective sleeve 181 on the rubber cylinder is seamlessly fitted with the upper end of the sealing piston sleeve 14; after seamless fitting, no liquid will enter between the protective sleeve 181 on the rubber cylinder and the upper end of the sealing piston sleeve 14, thereby reducing the amount of liquid filling, reducing unnecessary work, further improving the expansion efficiency of the rubber cylinder 21, and also reducing the liquid pressure borne by the protective sleeve 181 on the rubber cylinder. When the central tube 12 slides upward relative to the sealing piston sleeve 14, a second gap is formed between the protective sleeve 18-1 on the rubber cylinder and the upper end of the sealing piston sleeve 14, and the second gap is connected to the first gap. When unsealing, pull the central tube 12 upward, and refer to the pulling direction. Figure 5 In the direction of the horizontal arrow, the center tube 12 slides upward relative to the sealing piston sleeve, so that the gap between the protective sleeve 181 on the rubber cylinder and the front end of the sealing piston sleeve 14 gradually increases, and the liquid in the rubber cylinder 21 gradually injects into the gap between the protective sleeve 181 on the rubber cylinder and the front end of the sealing piston sleeve 14, so that the rubber cylinder 21 gradually and rapidly retracts, completing efficient unsealing.

[0059] See also Figure 3 and Figure 5 , further preferably, the above embodiment further includes a first temporary stop structure, which can temporarily prevent the center tube 12 from moving relative to the sealing piston sleeve 14; the first temporary stop structure is a structure that can be unlocked by pulling the center tube 12, and can adopt any existing known structural method. Furthermore, the first temporary stop structure is a first unsealing pin 20 that is set between the center tube 12 and the sealing piston sleeve 14 and can be sheared, and / or a first unsealing pin that is set between the center tube 12 and the lower protective sleeve 182 of the rubber cylinder and can be sheared. The "and / or" here is interpreted as "and" or "or", that is, the first temporary stop structure is the first unsealing pin 20 that can be sheared. The first unsealing pin 20 is set in one of the following three positions: the first position: between the central tube 12 and the sealing piston sleeve 14; the second position: between the central tube 12 and the rubber cylinder lower protective sleeve 182; the third position: between the central tube 12 and the sealing piston sleeve 14 and between the central tube 12 and the rubber cylinder lower protective sleeve 182. Before unsealing, the central tube 12 and the sealing piston sleeve 14 are temporarily fixed by the first unsealing pin to prevent relative sliding between the central tube 12 and the sealing piston sleeve 14. During unsealing, Figure 5 The center tube 12 is pulled upward, and the first unsealing pin 20 is sheared off by the force, allowing the center tube 12 to move upward relative to the sealing piston sleeve 14, completing the unsealing process. The unsealing process is described in Example 1. The first unsealing pin 20 can be unlocked directly, conveniently, and quickly, allowing the center tube 12 to move upward smoothly, completing the unsealing process.

[0060] See also Figure 2 Furthermore, preferably, the packer further includes a second temporary stop structure capable of temporarily preventing the setting piston 23 from moving relative to the setting piston sleeve 14. Furthermore, the second temporary stop structure comprises a second unsealing pin 24 disposed between the setting piston 23 and the setting piston sleeve 14 and capable of being sheared, and / or a second unsealing pin disposed between the setting piston 23 and the lower protective sleeve 182 of the rubber cartridge and capable of being sheared. The phrase "and / or" here means "and" or "or," meaning that the second temporary stop structure comprises a second unsealing pin capable of being sheared. The second unsealing pin can be disposed in one of the following three locations: first, between the setting piston 23 and the setting piston sleeve 14; second, between the setting piston 23 and the lower protective sleeve 182 of the rubber cartridge; and third, between both the setting piston 23 and the setting piston sleeve 14 and the lower protective sleeve 182 of the rubber cartridge. The second unsealing pin 24 can temporarily prevent the sealing piston 23 from sliding. During the sealing process, the second unsealing pin 24 can be cut off to achieve direct, convenient and fast unlocking, making it easier for the sealing piston 23 to move upward and complete the action of pushing the rubber cylinder 21.

[0061] See also Figure 2 and Figure 3In a further preferred embodiment of the above embodiment, the sealing piston sleeve 14 is provided with a piston sleeve drainage hole 141 that connects the gap between the rubber cylinder 21 and the sealing piston sleeve 14. A center tube drainage hole 122 is also provided on the sidewall of the center tube 12. The center tube 12 can be moved relative to the sealing piston sleeve 14 until the center tube drainage hole 122 aligns with the piston sleeve drainage hole 141. A first dissolvable locking device 171 is provided between the piston sleeve drainage hole 141 and the outer wall of the center tube 12. This first dissolvable locking device 171 can be a dissolvable ball or a dissolvable column made of a dissolvable metal. For example, before the sealing is completed, a portion of the dissolvable ball is engaged with the drainage hole 141, while the other portion is engaged with the spherical groove on the outer wall of the center tube 12. For example, before the sealing is completed, a portion of the dissolvable column is inserted into the drainage hole 141, while the other portion is engaged with the cylindrical groove on the outer wall of the center tube 12. The soluble balls or soluble columns further restrict the movement of the central tube 12. When the seal is set, the liquid injected into the rubber cylinder 21 will also enter the drainage hole 141 and contact the soluble balls or soluble columns. Within a certain period of time, the strength of the soluble balls or soluble columns will disappear, and the restriction on the central tube 12 will be released. Then, when the seal is released, the central tube 12 is pulled upward, and the liquid in the rubber cylinder 21 will first enter the gap between the protective sleeve 181 on the rubber cylinder and the upper end of the sealing piston sleeve 14, completing the gradual retraction of the rubber cylinder 21. The soluble balls or soluble columns are unlocked during the sealing process, and no additional unlocking operation is required. As the central tube 12 moves upward and reaches the designated position, the central tube drainage hole 122 corresponds to the piston sleeve drainage hole 141, and the liquid in the rubber cylinder 21 is discharged into the central tube through the piston sleeve drainage hole 141 and the central tube drainage hole 122, and then discharged smoothly.

[0062] See also Figure 7 and Figure 8 In a further preferred embodiment, the sealing piston sleeve 14 is provided with an unsealing liquid-permeable through hole 142, and a second soluble locking device 172 is provided between the unsealing liquid-permeable through hole 142 and the outer wall of the central tube 12. The sealing piston 23 is provided with a piston liquid-permeable hole 231. The sealing piston 23 can move relative to the sealing piston sleeve 14 until the piston liquid-permeable hole 231 is aligned with the unsealing liquid-permeable through hole 142, thereby introducing the unsealing liquid. Figure 7 and Figure 8 When the unsealing liquid-permeable through hole 142 is located within the lower protective sleeve 182, the lower protective sleeve 182 is provided with a lower protective sleeve through hole 1823 that communicates with the unsealing liquid-permeable through hole 142 and the piston liquid-permeable hole 231. If the unsealing liquid-permeable through hole 142 is located outside the lower protective sleeve 182, the lower protective sleeve through hole 1823 is not required and can be selected based on actual needs.

[0063] The second dissolvable locking device 172 can be a dissolvable ball or column made of a dissolvable metal. For example, before the seal is set, a portion of the dissolvable ball is locked in the unsealing liquid-permeable through-hole 142, while the remaining portion is locked in the spherical groove on the outer wall of the central tube 12. For example, before the seal is set, a portion of the dissolvable column is inserted into the unsealing liquid-permeable through-hole 142, while the remaining portion is locked in the cylindrical groove on the outer wall of the central tube 12. The dissolvable ball or column further restricts the movement of the central tube 12. During the sealing process, as the sealing piston 23 moves to the extreme position, the unsealing liquid-permeable hole 142 corresponds to the piston liquid-permeable hole 231, or the unsealing liquid-permeable hole 142, the piston liquid-permeable hole 231 and the lower protective sleeve hole 1823 correspond to each other, and then the liquid in the production casing 11 is introduced and contacts with the soluble balls or soluble columns. Within a certain period of time, the strength of the soluble balls or soluble columns disappears, and they can be pulled apart to complete the unlocking. The unlocking can be completed when the sealing is completed, without the need for additional unlocking operations. It is convenient and quick, and prepares for the subsequent movement of the central pipe.

[0064] See also Figure 2 With respect to the above embodiment, it is further preferred that the outer diameter of the rubber sleeve 21 in the non-expanded state is smaller than the outer diameter of the rubber sleeve upper protective sleeve 181 and / or the rubber sleeve lower protective sleeve 182. Here, "and / or" is interpreted as "and" or "or", that is, the outer diameter of the rubber sleeve 21 can be in the following forms: if the outer diameters of the rubber sleeve upper protective sleeve 181 and the rubber sleeve lower protective sleeve 182 are inconsistent, then the outer diameter of the rubber sleeve 21 can be smaller than the outer diameter of the rubber sleeve upper protective sleeve 181, or smaller than the outer diameter of the rubber sleeve lower protective sleeve 182, or smaller than the outer diameters of both the rubber sleeve upper protective sleeve 181 and the rubber sleeve lower protective sleeve 182; and when the outer diameters of the rubber sleeve upper protective sleeve 181 and the rubber sleeve lower protective sleeve 182 are the same, then the outer diameter of the rubber sleeve 21 is directly smaller than the outer diameters of both the rubber sleeve upper protective sleeve 181 and the rubber sleeve lower protective sleeve 182.

[0065] The outer diameter of the rubber cylinder 21 in the non-expanded state is at least 10 mm smaller than the outer diameter of the rubber cylinder upper protective sleeve 181 and / or the rubber cylinder lower protective sleeve 182. The outer diameter of the rubber cylinder upper protective sleeve 181 and / or the rubber cylinder lower protective sleeve 182 is at least 10 mm smaller than the inner diameter of the production casing, so that the diameter of the composite rubber cylinder packer of the present invention is much smaller than the inner diameter of the production casing. The rubber cylinder upper protective sleeve 181 and / or the rubber cylinder lower protective sleeve 182 can protect the rubber cylinder. Compared with the existing technology, it can be easily inserted into the horizontal section. The sealing and unsealing of the composite rubber cylinder packer are simple and convenient. At the same time, because the rubber cylinder 21 will not rub against the production casing under the protection of the large outer diameter of the rubber cylinder upper protective sleeve 181 and / or the rubber cylinder lower protective sleeve 182, the technical effect of improving the water finding efficiency of the horizontal well and extending the service life of the rubber cylinder packer is achieved, and the maintenance cost is also reduced.

[0066] In a further preferred embodiment of the above embodiment, a temporary locking mechanism is employed to limit relative sliding movement between the sealing piston 23 and the sealing piston sleeve 14 when the sealing piston 23 slides to its limit position. This temporary locking mechanism primarily prevents the sealing piston 23 from reversely moving after the sealing is complete, thereby affecting the sealing process. This temporary locking mechanism is intended to further ensure the sealing effect and can employ any conventionally simple locking mechanism, as long as it can prevent the sealing piston 23 from reversely moving. Because it does not need to withstand significant reverse thrust, the temporary locking mechanism does not require a complex structure. For example, it can employ one of the following two forms:

[0067] See also Figure 7 and Figure 8 Temporary locking mechanism 1: The outer wall of the central tube 12 is provided with a lock tongue cavity 127, within which a lock tongue ejection spring 129 is disposed. The inner end of the lock tongue 128 extends into the lock tongue cavity 127 and is connected to the lock tongue ejection spring 129. The outer end of the lock tongue 128 is spherical or curved, and its structure can be similar to that of a door lock. A lock hole 233 is provided at the bottom of the sealing piston 23 for inserting the outer end of the lock tongue 128. To facilitate compression of the lock tongue 128, an inclined surface A can be provided at the bottom of the end surface of the sealing piston 23 in front of the lock hole 233. When sealing begins, the sealing piston 23 moves upward to squeeze the lower end of the rubber cylinder 21. As the sealing piston 23 moves, it squeezes the lock tongue 128 from the inclined surface A, causing the lock tongue 128 to be compressed into the lock tongue cavity 127, thereby compressing the lock tongue ejection spring 129. When the travel of the sealing piston 23 ends, the locking hole 233 corresponds to the locking tongue cavity 127, and the outer end of the locking tongue 128 is pushed into the locking hole 233 to complete the locking. Figure 8 .

[0068] See also Figure 9 and Figure 10 , the second temporary locking mechanism: a locking cavity 144 is provided on the lower end face of the sealing piston sleeve 14, a locking barb 1441 is provided in the locking cavity 144, and two elastic barb lock cards 234 are provided on the end face of the sealing piston 23 corresponding to the lower end face of the sealing piston sleeve 14. When the sealing starts, the sealing piston 23 moves upward to squeeze the lower end of the rubber cylinder 21. As the sealing piston 23 moves, the two elastic barb lock cards 234 gradually extend into the locking cavity 144 and are squeezed inward, that is, the front ends of the two elastic barb lock cards 234 are squeezed together to form elastic deformation. When the stroke of the sealing piston 23 ends, the barbs on the two elastic barb lock cards 234 pass over the locking barbs 1441, and under the action of elasticity, they reset and clamp the locking barbs 1441 to lock. For the locked state, see Figure 10 .

[0069] The above two temporary locking mechanisms are merely exemplary examples of feasible solutions and are not exhaustive. Any existing structure that can achieve this function can be used.

[0070] See also Figure 4 and Figure 5 In accordance with the above embodiment, it is further preferred that a stepped surface be provided on the inner wall of the seating piston sleeve 14 and / or the inner wall of the lower protective sleeve 182 of the rubber cylinder. The term "and / or" herein means "and" or "or," meaning that the stepped surface may be provided only on the inner wall of the seating piston sleeve 14, only on the inner wall of the lower protective sleeve 182 of the rubber cylinder, or both. The stepped surface on the inner wall of the seating piston sleeve 14 is the piston sleeve stepped surface 143, and the stepped surface on the inner wall of the lower protective sleeve 182 of the rubber cylinder is the lower protective sleeve stepped surface 1822.

[0071] The outer wall of the central tube 12 is provided with bosses. The boss that can be connected to the piston sleeve stepped surface 143 is the first boss 124 , and the boss that can be connected to the lower protective sleeve stepped surface 1822 is the second boss 126 .

[0072] Here, the principle is explained in the manner that both the piston sleeve stepped surface 143 and the lower protective sleeve stepped surface 1822 are provided. Before unsealing, see Figure 4 A distance is maintained between the first boss 124 and the piston sleeve step surface 143, and between the second boss 126 and the lower protective sleeve step surface 1822. When unsealing begins, as the center tube 12 moves upward, the first boss 124 and the second boss 126 move toward the piston sleeve step surface 143 and the lower protective sleeve step surface 1822. When the first boss 124 is hooked to the piston sleeve step surface 143 and the second boss 126 is hooked to the lower protective sleeve step surface 1822, unsealing is completed. The entire composite rubber cartridge packer is pulled upward by the first boss 124 and the second boss 126 to complete the wellbore. The above structure serves as an auxiliary wellbore structure, making unsealing and wellbore exiting more convenient and quick.

[0073] See also Figures 2 to 6 , with respect to the above embodiment, it is further preferred that the composite rubber cylinder packer further includes a load-bearing fixed automatic unlocking mechanism. The load-bearing fixed automatic unlocking mechanism includes a load-bearing positioning column 16, the inner end of which passes through the through hole on the sealing piston sleeve 14 and extends into the load-bearing positioning hole 125 on the outer wall of the central tube 12, and a top spring 1251 is provided in the load-bearing positioning hole 125. In the locked state, the outer end of the load-bearing positioning column 16 is squeezed by the rubber cylinder 21 or the sealing piston 23 to be flush with the outer wall of the sealing piston sleeve 14, so that the inner end of the load-bearing positioning column 16 compresses the top spring 1251. This state can be seen in Figure 2 .

[0074] The inner wall of the sealing piston 23 is provided with a variable diameter cavity 232, which can accommodate the outer end of the load-bearing positioning column 16 when the sealing piston 23 moves. Furthermore, the inner end of the load-bearing positioning column 16 is spherical or conical. After the outer end of the load-bearing positioning column 16 extends into the variable diameter cavity 232, the spherical surface or conical inclined surface of the inner end of the load-bearing positioning column 16 aligns with the upper edge of the load-bearing positioning hole 125, forming a structure that allows the load-bearing positioning column 16 to completely exit the load-bearing positioning hole 125 through movement of the center tube 12.

[0075] The working principle of the load-bearing positioning column 16 is as follows: before the sealing is started, its upper end is squeezed by the rubber cylinder 21 or the sealing piston 23 until it is flush with the outer wall of the sealing piston sleeve 14. At this time, the lower part of the load-bearing positioning column 16 is located in the load-bearing positioning hole 125, which realizes the reinforcement and locking of the sealing piston 23 and the center tube. The load-bearing positioning column 16 has a higher locking strength than shearable pins. At the beginning of the sealing, as the sealing piston 23 moves upward, the diameter-changing cavity 232 corresponds to the upper end of the load-bearing positioning column 16, see Figure 3 Then, with the elastic force of the upper spring 1251, the upper end of the load-bearing positioning column 16 extends into the variable diameter cavity 232. At this time, the spherical surface or conical inclined surface of the lower end of the load-bearing positioning column 16 corresponds to the upper edge of the load-bearing positioning hole 125. Figure 4 and Figure 6 That is to say, at this time, only a small part of the lower end of the load-bearing positioning column 16 is located in the load-bearing positioning hole 125. At this time, the sealing piston 23 and the center tube are unlocked; after the unsealing begins, as the center tube moves upward, the upper edge of the load-bearing positioning hole 125 squeezes the spherical surface or conical inclined surface of the lower end of the load-bearing positioning column 16, forcing it to move upward and then completely leave the load-bearing positioning hole 125, so that the center tube moves upward smoothly and completes the unsealing process.

[0076] In the above structure, in order to more conveniently force the lower end of the load-bearing positioning column 16 to leave the load-bearing positioning hole 125 , an outwardly expanding slope surface B may be provided on the upper edge of the load-bearing positioning hole 125 .

[0077] The load-bearing fixed automatic unlocking mechanism can withstand a large load and prevent the center tube from moving relative to the seat seal piston sleeve due to misoperation, thereby affecting the operation.

[0078] illustrate

[0079] The above preferred technical solutions can be combined arbitrarily and then combined with the embodiments to form new embodiments, which will not be described in detail here.

[0080] The entire implementation process of the present invention is described below by taking an embodiment including all the above technical solutions as an example to facilitate understanding.

[0081] Sealing process:

[0082] The packer ball is put into the wellhead and pumped to the packer ball seat 3. A closed high-pressure environment is formed inside the central pipe. The liquid is driven by the high pressure. On the one hand, the high-pressure liquid enters the hydraulic cavity 1821, causing the second unsealing pin 24 to be sheared off, and the sealing piston 23 is pushed upward by the hydraulic pressure, compressing the lower end of the rubber cylinder 21. On the other hand, the high-pressure liquid enters the gap between the rubber cylinder 21 and the sealing piston sleeve 14 through the input through hole 121 and the hydraulic sealing check valve 15, expanding the rubber cylinder to achieve sealing. Figure 2 and Figure 3 . At this time, the liquid enters the piston sleeve drainage hole 141, and gradually completes the dissolution of the first soluble locking device 171 such as a soluble ball or a soluble column, so that the strength of the soluble ball or the soluble column disappears within a certain period of time, and the unlocking is completed. When the sealing piston 23 moves to the extreme position, it is limited by a temporary locking mechanism. At this time, the unsealing liquid permeable hole 142, the piston liquid permeable hole 231 and the lower protective sleeve hole 1823 correspond to each other, and then the liquid in the production casing 11 is introduced to dissolve the soluble ball or the soluble column of the second soluble locking device 172, so that the strength of the soluble ball or the soluble column disappears within a certain period of time, and the unlocking is completed. At the same time, under the elastic force of the upper spring 1251, the upper end of the load-bearing positioning column 16 extends into the variable diameter cavity 232, see Figure 4 and Figure 6 ; Sealing completed.

[0083] Unblocking process:

[0084] See also Figure 5 , pull up the oil pipe 10, drive the safety joint 8 and the center pipe 12 of the nearest composite rubber packer 7 upward, the pulling direction is as shown in Figure 5In the direction of the horizontal arrow, the first unsealing pin 20 is sheared by the force, and the bottom of the load-bearing positioning column 16 is pressed away from the load-bearing positioning hole 125. The center tube 12 drives the upper protective sleeve 181 of the rubber cylinder and the hydraulic seat seal check valve 15 to slide upward relative to the seat seal piston sleeve, causing the gap between the upper protective sleeve 181 of the rubber cylinder and the front end of the seat seal piston sleeve 14 to gradually increase. The liquid in the rubber cylinder 21 gradually flows into the gap between the upper protective sleeve 181 of the rubber cylinder and the front end of the seat seal piston sleeve 14, causing the rubber cylinder 21 to gradually retract and complete the unsealing. As the center tube 12 is lifted to the tool's designed travel distance, the first boss 124 engages the piston sleeve step surface 143 and the second boss 126 engages the lower protective sleeve step surface 1822 and locks, and the center tube stops sliding relative to the seat seal piston sleeve 14. At this time, the central tube drainage hole 122 coincides with the first soluble locking device 171, that is, the central tube drainage hole 122 is aligned with the piston sleeve drainage hole 141, further discharging the liquid in the rubber cylinder 21 to the central tube, that is, during the unsealing process, the upper end of the rubber cylinder 21 is pulled upward by the protective sleeve 181 on the rubber cylinder, and the distance between the upper and lower ends of the rubber cylinder 21 gradually returns to the length when it was lowered into the well, the unsealing of the packer is completed, and then the central tube 12 drives the entire composite rubber cylinder packer to go up and out of the well.

[0085] In summary, the composite rubber cartridge packer of the present invention effectively solves the problems of previous packers such as significant reliability impact, disadvantageous energy conservation, low working efficiency, complex structure, cumbersome operation and relatively high cost, and is conducive to promotion and application.

[0086] In the description of the present invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, a feature specified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0087] In the present invention, unless otherwise clearly specified and limited, the terms "install", "connect", "fix" and the like can be understood by ordinary technicians in this field according to the specific circumstances to have the specific meanings of the above terms in the present invention.

[0088] In the description of this specification, the description of the term "embodiment" or the like means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and the features of different embodiments or examples, unless they are mutually inconsistent.

[0089] Although the embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. A person skilled in the art may alter, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A composite rubber packer for being lowered into a production casing (11), the packer comprising a central tube (12) and a rubber upper protective sleeve (181), a rubber tube (21), a sealing piston (23) and a rubber lower protective sleeve (182) which are sequentially sleeved on the outer wall of the central tube (12); the upper end of the rubber tube (21) is connected to the rubber upper protective sleeve (181), and the lower end is connected to the sealing piston (23), and the diameter of the rubber tube (21) in a non-expanded state is smaller than the inner diameter of the production casing (11); the lower end of the sealing piston (23) is located in the cavity of the rubber lower protective sleeve (182), and a hydraulic cavity (1821) for liquid injection is formed between the sealing piston (23) and the rubber lower protective sleeve (182); the side wall of the central tube (12) is further provided with a liquid injection through hole (123) which can communicate with the hydraulic cavity (1821), characterized in that: The outer wall of the center tube (12) is also provided with a seat sealing piston sleeve (14), and the center tube (12) can slide in a dynamic sealing manner relative to the seat sealing piston sleeve (14); the seat sealing piston sleeve (14) is located between the upper protective sleeve (181) of the rubber cylinder and the lower protective sleeve (182) of the rubber cylinder, and the seat sealing piston sleeve (14) is connected to the lower protective sleeve (182) of the rubber cylinder; the rubber cylinder (21) and the seat sealing piston (23) are sleeved outside the seat sealing piston sleeve (14), and a first gap is formed between the rubber cylinder (21) and the seat sealing piston sleeve (14), and the seat sealing piston (23) can slide in a dynamic sealing manner relative to the seat sealing piston sleeve (14); when the seat sealing piston (23) slides upward relative to the seat sealing piston sleeve (14), the seat sealing piston (23) compresses the lower end of the rubber cylinder (21); The upper protective sleeve (181) of the rubber cylinder is fixedly connected to the outside of the central tube (12); a hydraulic seat seal one-way valve (15) is installed in the upper protective sleeve (181) of the rubber cylinder, the input end of the hydraulic seat seal one-way valve (15) is communicated with the input through hole (121) located on the side wall of the central tube (12), and the output end of the hydraulic seat seal one-way valve (15) is communicated with the first gap; In the initial state, the upper protective sleeve (181) of the rubber cylinder is seamlessly fitted to the upper end of the sealing piston sleeve (14); when the central tube (12) slides upward relative to the sealing piston sleeve (14), a second gap is formed between the upper protective sleeve (181) of the rubber cylinder and the upper end of the sealing piston sleeve (14), and the second gap is connected to the first gap; In the non-expanded state, the outer diameter of the rubber cylinder (21) is at least 10 mm smaller than the outer diameter of the rubber cylinder upper protective sleeve (181) and / or the rubber cylinder lower protective sleeve (182); the outer diameter of the rubber cylinder upper protective sleeve (181) and / or the rubber cylinder lower protective sleeve (182) is at least 10 mm smaller than the inner diameter of the production casing (11).

2. The composite rubber packer according to claim 1, characterized in that: The packer further includes a first temporary stop structure, which can temporarily prevent the center pipe (12) from moving relative to the sealing piston sleeve (14); the first temporary stop structure is a first unsealing pin arranged between the center pipe (12) and the sealing piston sleeve (14) and capable of being sheared off, and / or a first unsealing pin arranged between the center pipe (12) and the lower protective sleeve (182) of the rubber cylinder and capable of being sheared off.

3. The composite rubber packer according to claim 1, wherein: The packer further comprises a second temporary stop structure, wherein the second temporary stop structure is capable of temporarily preventing the sealing piston (23) from moving relative to the sealing piston sleeve (14); The second temporary stop structure is a second unsealing pin that is arranged between the sealing piston (23) and the sealing piston sleeve (14) and can be sheared off, and / or a second unsealing pin that is arranged between the sealing piston (23) and the lower protective sleeve (182) of the rubber cylinder and can be sheared off.

4. The composite rubber packer according to claim 1, wherein: The sealing piston sleeve (14) is provided with a piston sleeve drainage hole (141) communicating with the first gap, and the side wall of the center tube (12) is also provided with a center tube drainage hole (122). The center tube (12) can be moved relative to the sealing piston sleeve (14) until the center tube drainage hole (122) is aligned with the piston sleeve drainage hole (141); a first soluble locking device (171) is provided between the piston sleeve drainage hole (141) and the outer wall of the center tube (12).

5. The composite rubber packer according to claim 1, wherein: The sealing piston sleeve (14) is provided with an unsealing liquid-permeable through hole (142), and a second soluble locking device (172) is provided between the unsealing liquid-permeable through hole (142) and the outer wall of the central tube (12); the sealing piston (23) is provided with a piston liquid-permeable hole (231), and the sealing piston (23) can move relative to the sealing piston sleeve (14) until the piston liquid-permeable hole (231) is aligned with the unsealing liquid-permeable through hole (142), thereby introducing unsealing liquid.

6. The composite rubber packer according to claim 1, wherein: When the sealing piston (23) slides to the limit position, the relative sliding between it and the sealing piston sleeve (14) can be restricted by a temporary locking mechanism.

7. The composite rubber packer according to claim 1, wherein: The inner wall of the sealing piston sleeve (14) and / or the inner wall of the rubber cylinder lower protective sleeve (182) are provided with a stepped surface, and the outer wall of the central tube (12) is provided with a boss. When the central tube (12) moves to the extreme position, the boss is engaged with the stepped surface.

8. The composite rubber packer according to claim 1, wherein: It also includes a load-bearing fixed automatic unlocking mechanism; the load-bearing fixed automatic unlocking mechanism includes a load-bearing positioning column (16), the inner end of the load-bearing positioning column (16) passes through the through hole on the sealing piston sleeve (14) and extends into the load-bearing positioning hole (125) on the outer wall of the central tube (12), and an upper spring (1251) is provided in the load-bearing positioning hole (125); in the locked state, the outer end of the load-bearing positioning column (16) is squeezed by the rubber cylinder (21) or the sealing piston (23) to be flush with the outer wall of the sealing piston sleeve (14), so that the inner end of the load-bearing positioning column (16) compresses the upper spring (1251); The inner wall of the sealing piston (23) is provided with a diameter-changing cavity (232) capable of accommodating the outer end of the load-bearing positioning column (16) when the sealing piston (23) moves.

9. A horizontal well segmented water finding string, characterized by: The water-finding string comprises the composite rubber packer (7) according to any one of claims 1 to 8; The rear end of the water-finding string is provided with a guide (1), the upper end of the guide (1) is connected to the lower end of the hole-opening circulation short section (2), the upper end of the hole-opening circulation short section (2) is connected to the lower end of the packer seat sealing ball seat (3), the upper end of the packer seat sealing ball seat (3) is connected to the composite rubber packer (7), there are multiple composite rubber packers (7), and the multiple composite rubber packers (7) are connected end to end through oil pipes; a one-way flow tracer short section (6) corresponding to the horizontal well perforation section (5) is provided on the oil pipe at the lower end of each composite rubber packer (7).

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