A high-pressure packer, an oil and water well leakage point detection device, a system and an application thereof

Abstract

The application discloses a high-pressure packer, an oil-water well leakage point detection device, a system and application thereof. The first joint and the second joint of the packer are detachably connected with the central pipe. The inner rubber sleeve is arranged outside the central pipe and forms a hydraulic cavity. The central pipe is provided with a first fluid passage in communication with the hydraulic cavity. The first lock ring is arranged outside the central pipe and located between one end of the inner rubber sleeve and the central pipe. The second lock ring is arranged outside the central pipe and located between the inner rubber sleeve and the central pipe. The steel band skeleton is arranged outside the inner rubber sleeve. The outer rubber sleeve is arranged outside the steel band skeleton. The first compression ring is arranged outside the first joint, the first lock ring, the inner rubber sleeve and the steel band skeleton. The high-pressure sealing aid ring is arranged outside the central pipe. The second compression ring is arranged outside the second lock ring, the inner rubber sleeve, the steel band skeleton and the high-pressure sealing aid ring. The packer can be hydraulically set and released without mechanical movement such as lifting and lowering, and is more suitable for leakage finding operation and has unique advantages in horizontal wells and high-inclination wells.

Description

Technical Field

[0001] This invention relates to the field of downhole completion technology for oil and gas wells, and particularly to a high-pressure packer, a leak detection device and system for oil and water wells, and their applications. Background Technology

[0002] During water injection development in oilfields, frequent changes in formation displacement and geostress, along with downhole operations and fluid corrosion, lead to damage to the casing of oil and water wells. This damage manifests primarily as ruptures, breaks, casing diameter reduction, and bending, ultimately resulting in an increase in high water-cut wells and a decrease in single-well production. In casing well remediation, the ability to quickly and accurately locate the casing damage becomes crucial for subsequent operations.

[0003] Currently, the most common and accurate method for finding leaks is packer leak finding. Leak finding operations require packers to have good passability (passability means that the maximum outer diameter of the leak finding tool should be as small as possible, and friction with the wellbore should be minimized when it is lowered into the well or moved multiple times, so as to reduce the wear of the rubber sleeve and ensure its service life) and expansion capacity in the wellbore. That is, a small packer can achieve the sealing of a large wellbore and has the characteristics of high pressure resistance and sealing. Summary of the Invention

[0004] The inventors discovered that most packer sleeves have limited expansion coefficients, making it difficult to simultaneously achieve wellbore passability and high-pressure sealing. Furthermore, in highly deviated and horizontal well sections, gravity causes the packer to sink to the underside of the casing, preventing the setting sleeve from expanding uniformly circumferentially and hindering effective sealing under high pressure. Accurate leak detection requires repeated setting and unsetting of the packer at multiple locations within the well, necessitating the up-and-down movement of the packer to change its setting position. Existing packers have limited shrinkage and generally exhibit significant residual deformation, easily wearing down the sleeve. A single leak detection operation may require multiple packer replacements, greatly increasing the difficulty and cost of the operation.

[0005] Meanwhile, in order to achieve accurate leak detection, after pressurizing to the predetermined pressure, the pump needs to be stopped and the pressure stabilized. By observing the pressure change, it is determined whether there is a leak in the casing. The existing throttles used in conjunction with the expansion packer will continuously reduce the pressure difference when the pump is stopped and the pressure stabilized, thereby affecting the sealing performance of the packer (especially under high pressure). During leak detection, it is difficult to determine whether the pressure drop is caused by packer leakage or by the presence of a leak, which affects the accuracy of the leak detection operation.

[0006] In view of the above problems, the present invention is proposed to provide a high-pressure packer, an oil and water well leakage detection device, system and application thereof that overcomes or at least partially solves the above problems.

[0007] In a first aspect, embodiments of the present invention provide a high-pressure packer, which may include: a first connector, a central tube, a first locking ring, a first pressure ring, an inner rubber cylinder, a steel strip skeleton, an outer rubber cylinder, a second pressure ring, a second locking ring, a high-pressure sealing ring, and a second connector;

[0008] The first connector and the second connector are detachably connected to the central tube, respectively.

[0009] The inner rubber sleeve is fitted outside the central tube, forming a hydraulic cavity between the inner rubber sleeve and the central tube. A first fluid channel communicating with the hydraulic cavity is provided on the central tube. The first locking ring is fitted outside the central tube, located between one end of the inner rubber sleeve and the central tube, and is limited by the end of the first connector. The second locking ring is fitted outside the central tube, located between the other end of the inner rubber sleeve and the central tube, and is limited by the end of the second connector.

[0010] The steel strip skeleton is sleeved on the outside of the inner rubber cylinder, and the outer rubber cylinder is sleeved on the outside of the steel strip skeleton; the first pressure ring is sleeved on the outside of the first joint, the first locking ring, the inner rubber cylinder, and the steel strip skeleton; the high-pressure sealing ring is sleeved on the outside of the central tube, located between the second locking ring and the second joint; the second pressure ring is sleeved on the outside of the second locking ring, the inner rubber cylinder, the steel strip skeleton, and the high-pressure sealing ring; the first pressure ring is detachably connected to the first joint, and the second pressure ring is detachably connected to the high-pressure sealing ring.

[0011] Optionally, a preset gap is reserved between the high-pressure sealing ring and the second locking ring.

[0012] Optionally, the outer side of the first locking ring is provided with a first annular groove; the outer side of the second locking ring is provided with a second annular groove;

[0013] The inner side of the inner tube is provided with a first annular boss that matches the first annular groove and a second annular boss that matches the second annular groove.

[0014] The outer side of the inner rubber cylinder is provided with a third annular boss and a fourth annular boss, the inner side of the first pressure ring is provided with a third annular groove that matches the third annular boss, and the inner side of the second pressure ring is provided with a fourth annular groove that matches the fourth annular boss.

[0015] Optionally, the steel strip frame is glued and fixed to the inner rubber cylinder and the outer rubber cylinder respectively.

[0016] Optionally, the first connector and the second connector are respectively threaded to the central pipe;

[0017] And / or,

[0018] The first pressure ring is threadedly connected to the first connector;

[0019] And / or,

[0020] The second pressure ring is threadedly connected to the high-pressure sealing ring.

[0021] Optionally, the high-pressure packer may also include: a first sealing ring, a second sealing ring, and / or a third sealing ring;

[0022] The outer side of the first connector is provided with a fifth annular groove, and the first sealing ring is located in the fifth annular groove; the first pressure ring is nested on the outer side of the first sealing ring;

[0023] The high-pressure sealing ring has a sixth annular groove on its outer side, and the second sealing ring is located in the sixth annular groove; the second pressure ring is nested on the outside of the second sealing ring;

[0024] The high-pressure sealing ring has a seventh annular groove on its inner side, and the third sealing ring is located in the seventh annular groove.

[0025] In a second aspect, embodiments of the present invention provide an oil and water well leakage detection device, which may include: a constant pressure throttle and at least one high pressure packer as described in the first aspect;

[0026] The constant pressure throttle is detachably connected to the second connector.

[0027] Optionally, the constant pressure throttle may include: a third connector, a fourth connector, a central body, a fixing ring, a pressure adjusting shaft, a bearing tray, a first spring, a first ball, and a ball seat;

[0028] The bottom of the third connector is detachably connected to the upper part of the fourth connector;

[0029] The central body is cylindrical and is embedded inside the third connector, and is fixedly connected to the third connector; a second fluid channel is provided on the side wall of the third connector, and a third fluid channel corresponding to the second fluid channel is provided on the side wall of the central body; a fourth fluid channel is formed between the central body and the third connector and the hollowed-out part of the ball seat.

[0030] The fixing ring is detachably connected to the upper part of the central body, and the ball seat is detachably connected to the lower part of the central body; the support plate is located below the fixing ring and is limited by the fixing ring; the first ball sits on the ball seat, and the first spring is located between the first ball and the support plate; the pressure adjusting shaft is threadedly connected to the fixing ring, and after the pressure adjusting shaft rotates, it abuts against the support plate to compress the first spring.

[0031] Optionally, the constant pressure throttle may further include a straightening ring located between the first ball and the first spring.

[0032] Optionally, the central body and the third connector are welded together through the channel walls of the second fluid channel and the third fluid channel.

[0033] Optionally, the third connector of the constant pressure throttle is threadedly connected to the second connector;

[0034] And / or, the retaining ring is threadedly connected to the upper part of the central body, and the ball seat is threadedly connected to the lower part of the central body.

[0035] Optionally, the oil and water well leakage detection device may further include: a one-way valve assembly; the upper connector of the one-way valve assembly is detachably connected to the first connector of the high-pressure packer or the fourth connector of the constant-pressure throttle.

[0036] Optionally, the one-way valve assembly may include: an upper connector, a sealing body, a coupling, a sand filter tube, a guide, a fixed plug, a second spring, a support plug, and a second ball;

[0037] One end of the sealing body is detachably connected to the upper connector, and the other end is connected to one end of the sand filter tube via the coupling; the other end of the sand filter tube is connected to the guide.

[0038] The sealing body has a hollow center, and the inner diameter of the portion of the sealing body near the sand filter pipe is smaller than the inner diameter of at least a portion of the portion away from the sand filter pipe; the second sphere, the support plug, the second spring, and the fixing plug are located in the hollow portion of the sealing body, the diameter of the second sphere is larger than the inner diameter of the portion of the sealing body near the sand filter pipe, and the fixing plug is connected to the sealing body; the support plug abuts against the second sphere, and the second spring is located between the support plug and the fixing plug; a fifth fluid channel is provided on the fixing plug, and a sixth fluid channel is provided on the support plug.

[0039] Thirdly, embodiments of the present invention provide an oil and water well leakage detection system, which may include: casing, water injection device, pressure detection device, and the oil and water well leakage detection device as described in the second aspect.

[0040] The oil and water well leakage detection device is used to be lowered into the casing at the location to be detected;

[0041] The water injection device is used to inject water into the oil-water well leakage detection device through the high-pressure pump and oil pipe of the water injection device;

[0042] The constant pressure throttle is used to keep the pressure difference inside and outside the oil pipe constant after the high pressure pump stops injecting water;

[0043] The high-pressure packer is set to seal the casing and the tubing at the location to be tested;

[0044] The pressure detection device is used to detect pressure changes in the oil pipe.

[0045] Fourthly, embodiments of the present invention provide an application of the oil and water well leakage detection device as described in the second aspect in an oil and water well leakage detection system.

[0046] The beneficial effects of the above-mentioned technical solutions provided in the embodiments of the present invention include at least the following:

[0047] This invention provides a high-pressure packer, an oil and water well leak detection device, a system, and their applications. The high-pressure packer's rubber sleeve is hydraulically set and unsealed, which is simple and easy to implement, reusable, and more suitable for leak detection operations. Moreover, it does not require mechanical movement during operation, meaning that compared to conventional packers, it does not require lifting or lowering to set and unseal. This gives it unique advantages in horizontal and highly deviated wells and has broad application prospects.

[0048] Furthermore, the aforementioned packer portion in this embodiment comprises a three-layer structure packer consisting of an inner packer, a steel strip skeleton, and an outer packer. The packer has a large expansion coefficient, good expansion properties, and strong adaptability to wellbore. It can achieve the sealing of large-diameter wellbores with small-diameter packers and can be used for setting and sealing in casing deformation wells and open-hole wells. The three-layer structure packer has good shrinkage properties, with small residual deformation during unsealing, which greatly increases the lifespan of the packer.

[0049] Furthermore, this high-pressure packer can be used in both directions (upside down). After setting, the high-pressure sealing ring moves under hydraulic pressure to compress the rubber cylinder, which can achieve high-pressure sealing and ensure the high pressure sealing performance of the high-pressure packer.

[0050] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the written description and the accompanying drawings.

[0051] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0052] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0053] Figure 1 This is a schematic diagram of the high-pressure packer provided in an embodiment of the present invention;

[0054] Figure 2 for Figure 1 One of the enlarged views of a section in the middle;

[0055] Figure 3 for Figure 1 The second enlarged view of a section in the middle;

[0056] Figure 4 This is a schematic diagram of the constant pressure throttle provided in an embodiment of the present invention;

[0057] Figure 5 This is an axial cross-sectional view of the constant pressure throttle provided in an embodiment of the present invention;

[0058] Figure 6 This is a schematic diagram of the one-way valve assembly provided in an embodiment of the present invention;

[0059] Figure 7 This is a schematic diagram of the assembly of the oil and water well leakage detection device for locating the bottom boundary of the leakage point provided in this embodiment of the invention;

[0060] Figure 8 This is a schematic diagram of the top boundary of the leak detection device for oil and water wells provided in this embodiment of the invention.

[0061] Figure 9 This is a schematic diagram of the assembly of the double packer leak detection device for oil and water wells provided in this embodiment of the invention.

[0062] 1-High-pressure packer; 2-Constant-pressure throttle; 3-Check valve assembly;

[0063] 101-First connector; 102-Central tube; 103-First locking ring; 104-First pressure ring; 105-Inner rubber sleeve; 106-Steel strip skeleton; 107-Outer rubber sleeve; 108-Second pressure ring; 109-Second locking ring; 110-High-pressure sealing ring; 111-Second connector; 112-Hydraulic chamber; 113-First fluid channel; 114-First sealing ring; 115-Second sealing ring; 116-Third sealing ring; 1031-First annular groove; 1091-Second annular groove; 1051-First annular boss; 1052-Second annular boss; 1053-Third annular boss; 1054-Fourth annular boss; 1041-Third annular groove; 1081-Fourth annular groove; 1011-Fifth annular groove; 1101-Sixth annular groove; 1102-Seventh annular groove;

[0064] 201-Third connector; 202-Fourth connector; 203-Center body; 204-Fixing ring; 205-Pressure adjusting shaft; 206-Bearing tray; 207-First spring; 208-First ball; 209-Ball seat; 210-Straightening ring; 211-Second fluid channel; 212-Third fluid channel; 213-Fourth fluid channel;

[0065] 301-Upper connector; 302-Sealing body; 303-Coupling; 304-Sand filter pipe; 305-Guide; 306-Fixing plug; 307-Second spring; 308-Support plug; 309-Second ball; 310-Fifth fluid channel; 311-Sixth fluid channel. Detailed Implementation

[0066] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0067] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," "outer," "far," "near," "front," and "rear," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0068] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0069] This invention provides a high-pressure packer that can effectively set and seal in highly deviated and horizontal well sections. The packer expands by hydraulic pressure onto the rubber sleeve, eliminating the need for mechanical movements such as lifting and lowering to achieve setting and unsealing.

[0070] Reference Figure 1As shown, the high-pressure packer 1 may include: a first connector 101, a central tube 102, a first locking ring 103, a first pressure ring 104, an inner rubber cylinder 105, a steel strip skeleton 106, an outer rubber cylinder 107, a second pressure ring 108, a second locking ring 109, a high-pressure auxiliary sealing ring 110, and a second connector 111.

[0071] The first connector 101 and the second connector 111 are detachably connected to the central tube 102, respectively.

[0072] An inner rubber sleeve 105 is fitted onto the outside of a central tube 102, forming a hydraulic cavity 112 between the inner rubber sleeve 105 and the central tube 102. A first fluid channel 113 communicating with the hydraulic cavity 112 is provided on the central tube 102. A first locking ring 103 is fitted onto the outside of the central tube 102, located between one end of the inner rubber sleeve 105 and the central tube 102, and is limited by the end of a first connector 101. A second locking ring 109 is fitted onto the outside of the central tube 102, located between the other end of the inner rubber sleeve 105 and the central tube 102, and is limited by the end of a second connector 111.

[0073] A steel strip skeleton 106 is fitted outside the inner rubber sleeve 105, and an outer rubber sleeve 107 is fitted outside the steel strip skeleton 106; a first pressure ring 104 is fitted outside the first connector 101, a first locking ring 103, an inner rubber sleeve 105, and a steel strip skeleton 106; a high-pressure sealing ring 110 is fitted outside the central tube 102, located between the second locking ring 109 and the second connector 111; a second pressure ring 108 is fitted outside the second locking ring 109, an inner rubber sleeve 105, a steel strip skeleton 106, and a high-pressure sealing ring 110; the first pressure ring 104 is detachably connected to the first connector 101, and the second pressure ring 108 is detachably connected to the high-pressure sealing ring 110.

[0074] The packer provided in this embodiment of the invention is an expansion-type high-pressure packer, and its working principle is as follows: When in use, it is lowered to a predetermined position (layer) through an oil pipe, water is injected into the oil pipe to pressurize it, and water enters the hydraulic chamber from the first fluid channel of the central pipe. The hydraulic pressure pushes the rubber sleeve to expand and achieve setting and sealing. Depressurization and contraction can release the seal.

[0075] It should be noted that the steel strip skeleton in this embodiment of the invention is formed by cold rolling and folding multiple layers of stainless steel strip, possessing good elasticity and shrinkage. The inner and outer rubber cylinders are made of highly elastic rubber, and are bonded to the steel strip skeleton through a vulcanization process, forming a three-layer structure rubber cylinder with stainless steel strip as the skeleton layer. It should also be noted that by connecting to the packer through a throttle and a one-way valve, a pressure difference will appear above and below the rubber cylinder after the packer is set. Under the action of this pressure difference, the high-pressure sealing ring will move a short distance to compress the inner rubber cylinder, achieving high-pressure sealing.

[0076] The high-pressure packer provided in this invention aims to solve the problems of conventional packers failing to achieve high-pressure sealing during leak detection in horizontal or highly deviated well sections of deep wells, and the severe wear and drastic shortening of the packer sleeve due to frequent up-and-down dragging and repeated setting. This high-pressure packer sleeve is hydraulically set and unset, simple and easy to use, reusable, and more suitable for leak detection operations. Furthermore, it requires no mechanical movement during operation, meaning that setting and unsetting does not require lifting and lowering compared to conventional packers. This offers unique advantages in horizontal and highly deviated wells and has broad application prospects.

[0077] Furthermore, the aforementioned packer portion in this embodiment comprises a three-layer structure packer consisting of an inner packer, a steel strip skeleton, and an outer packer. The packer has a large expansion coefficient, good expansion properties, and strong adaptability to wellbore. It can achieve the sealing of large-diameter wellbores with small-diameter packers and can be used for setting and sealing in casing deformation wells and open-hole wells. The three-layer structure packer has good shrinkage properties, with small residual deformation during unsealing, which greatly increases the lifespan of the packer.

[0078] Furthermore, this high-pressure packer can be used in both directions (upside down). After setting, the high-pressure sealing ring moves under hydraulic pressure to compress the rubber cylinder, which can achieve high-pressure sealing and ensure the high pressure sealing performance of the high-pressure packer.

[0079] In an optional embodiment, refer to Figure 1 As shown, a preset gap is reserved between the high-pressure sealing ring 110 and the second locking ring 109. This allows the high-pressure sealing ring to move short distances up and down under hydraulic pressure, achieving high-pressure sealing and ensuring the packer's high pressure-bearing sealing performance.

[0080] It should be noted that the hydraulic pressure in this embodiment refers to the different pressures on the upper and lower sides of the packer after the packer is set. This hydraulic pressure is generated by the throttle connected during use, which will be explained in detail below.

[0081] In another alternative embodiment, refer to Figure 1 , Figure 2 and Figure 3 As shown, the outer side of the first locking ring 103 is provided with a first annular groove 1031; the outer side of the second locking ring 109 is provided with a second annular groove 1091.

[0082] The inner side of the inner rubber cylinder 105 is provided with a first annular boss 1051 that matches the first annular groove 1031 and a second annular boss 1052 that matches the second annular groove 1091.

[0083] The outer side of the inner rubber cylinder 105 is provided with a third annular boss 1053 and a fourth annular boss 1054. The inner side of the first pressure ring 104 is provided with a third annular groove 1041 that matches the third annular boss 1053. The inner side of the second pressure ring 108 is provided with a fourth annular groove 1081 that matches the fourth annular boss 1054.

[0084] In this embodiment, the inner rubber tube is fixed at both ends by the engagement of the annular groove and the annular boss, and then by the locking ring and the pressure ring. When water is injected, the middle part of the rubber tube expands to achieve a set seal; when the pressure is released and the seal is broken, the rubber tube quickly and elastically resets. The engagement of the annular groove and the annular boss not only increases the fixing friction but also enhances the sealing performance between the components.

[0085] In another optional embodiment, the steel strip skeleton 106 is bonded and fixed to the inner rubber sleeve 105 and the outer rubber sleeve 107, respectively. In this embodiment, the steel strip skeleton is formed by cold rolling and folding multiple layers of stainless steel strip, possessing good elasticity and shrinkage. The inner and outer rubber sleeves are made of highly elastic rubber, and are bonded and fixed to the steel strip skeleton through a vulcanization process, forming a three-layer rubber sleeve structure with stainless steel strip as the skeleton layer. The expansion and contraction properties of this three-layer rubber sleeve are superior to those of existing single-layer rubber sleeves.

[0086] In another alternative embodiment, refer to Figure 1 As shown, the first connector 101 and the second connector 111 are respectively threaded to the central tube 102;

[0087] And / or,

[0088] The first pressure ring 104 is threadedly connected to the first connector 101;

[0089] And / or,

[0090] The second pressure ring 108 is threadedly connected to the high-pressure sealing ring 110.

[0091] In this embodiment, the aforementioned components are connected by threads, which makes the connection more convenient and secure, and also facilitates disassembly for replacement of damaged components. It should be noted that the "and / or" in this embodiment refers to at least one pair of components being connected by threads.

[0092] In another alternative embodiment, refer to Figure 1 , Figure 2 and Figure 3 As shown, the high-pressure packer 1 may further include: a first sealing ring 114, a second sealing ring 115 and / or a third sealing ring 116;

[0093] The outer side of the first connector 101 is provided with a fifth annular groove 1011, and the first sealing ring 114 is located in the fifth annular groove 1011; the first pressure ring 104 is nested outside the first sealing ring 114.

[0094] The high-pressure sealing ring 110 has a sixth annular groove 1101 on its outer side, and the second sealing ring 115 is located in the sixth annular groove 1101; the second pressure ring 108 is nested outside the second sealing ring 115.

[0095] The high-pressure sealing ring 110 has a seventh annular groove 1102 on its inner side, and the third sealing ring 116 is located in the seventh annular groove 1102.

[0096] The combination of the annular groove and the sealing ring in this embodiment of the invention can ensure the sealing between various components, and also ensure the sealing of the hydraulic cavity.

[0097] Based on the same inventive concept, this embodiment of the invention also provides an oil and water well leakage detection device, which may include: a constant pressure throttle 2 and at least one of the above-mentioned high pressure packers 1;

[0098] Reference Figure 1 and Figure 4 As shown, the constant pressure throttle 2 is detachably connected to the second connector 111.

[0099] The oil-water well leakage detection device provided in this embodiment of the invention uses a constant pressure throttle to provide a constant pressure difference between the inside and outside of the tubing after the high-pressure pump stops injecting water, and this pressure difference is adjustable. During leakage detection, the constant pressure throttle is connected to one end of the second connector of the high-pressure packer. After the high-pressure packer is set, the rubber sleeve sets the wellbore or bare well. The pressure is higher on the side near the constant pressure throttle, and under this hydraulic action, the high-pressure sealing ring can move a short distance to achieve high-pressure sealing, ensuring the high-pressure sealing performance of the packer.

[0100] In another alternative embodiment, refer to Figure 4 As shown, the constant pressure throttle 2 may include: a third connector 201, a fourth connector 202, a central body 203, a fixing ring 204, a pressure adjusting shaft 205, a support plate 206, a first spring 207, a first ball 208, and a ball seat 209;

[0101] The bottom of the third connector 201 is detachably connected to the upper part of the fourth connector 202;

[0102] The central body 203 is cylindrical and is embedded inside the third connector 201, and is fixedly connected to the third connector 201; a second fluid channel 211 is provided on the side wall of the third connector 201, and a third fluid channel 212 corresponding to the second fluid channel 211 is provided on the side wall of the central body 203; a fourth fluid channel 213 is formed between the central body 203 and the third connector 201 and in the hollowed-out part of the ball seat 209.

[0103] The retaining ring 204 is detachably connected to the upper part of the center body 203, and the ball seat 209 is detachably connected to the lower part of the center body 203; the support plate 206 is located below the retaining ring 204 and is limited by the retaining ring 204; the first ball 208 is located on the ball seat 209, and the first spring 207 is located between the first ball 208 and the support plate 206; the pressure adjusting shaft 205 is threadedly connected to the retaining ring 204, and after the pressure adjusting shaft 205 rotates, it abuts against the support plate 206 to compress the first spring 207.

[0104] In this embodiment of the invention, the pressure-regulating throttle is used such that one end is connected to an oil pipe or the high-pressure packer, while the other end is sealed off. The support tray is disc-shaped, supporting the lower end face of the pressure-regulating shaft on top and the upper end face of the spring on the bottom, with a seal between the tray and the central body in the circumferential direction. The first sphere can be a steel ball with a diameter larger than the inner diameter of the hollowed-out portion of the ball seat. During assembly, the first spring is in a compressed state, pressing the first sphere against the ball seat. Under spring pressure, the first sphere abuts against the ball seat, closing the fluid passage at the ball seat. The hydraulic pressure at which the first sphere moves upward away from the ball seat under hydraulic pressure is the starting pressure of the adjustable pressure-regulating throttle. When the pressure-regulating shaft rotates clockwise to push the support tray downward, the first spring can continue to compress, causing a greater force to press the first sphere against the ball seat, thereby increasing the starting pressure of the adjustable pressure-regulating throttle.

[0105] Reference Figure 4 and Figure 1 As shown, the working principle of the pressure-regulating throttle in this embodiment of the invention is as follows: The high-pressure water pump pressurizes the oil pipe, and the lower end of the pressure-regulating throttle 2 is closed (it can be closed using a check valve, which will be described in detail below, or it can be closed by other means), and the pressure in the oil pipe begins to rise (the fourth fluid channel 213 is connected to the oil pipe and the central pipe 102 of the high-pressure packer 1). When the pressure in the oil pipe rises to the starting pressure P0 of the pressure-regulating throttle 2, the hydraulic pressure pushes the first ball 208 upward and compresses the first spring 207. At this time, the first ball 208 separates from the ball seat 209, and the liquid enters the annulus outside the pipe through the second fluid channel 211 and the third fluid channel 212. As the liquid in the annulus outside the pipe increases, the pressure outside the oil pipe rises. When the pressure P inside and outside the oil pipe... 内 -P 外When the pressure is less than P0, the first ball 208 returns to its original position under the elastic force of the first spring 207 and abuts against the ball seat 209 to close the fluid passage (part of the fourth fluid passage 213) on the ball seat 209. As the pressure inside the oil pipe continues to increase, the pressure difference between the inside and outside of the oil pipe is once again greater than the starting pressure P0, and the first ball 208 separates from the ball seat 209 again. This process repeats, so that the pressure difference between the inside and outside of the oil pipe is always maintained at around the starting pressure P0.

[0106] While the high-pressure pump pressurizes the oil pipe, the fluid enters the hydraulic chamber 112 between the central pipe 102 and the inner rubber sleeve 105 through the first fluid channel 113 on the central pipe 102. Under the action of the internal and external pressure difference P0 generated by the adjustable constant pressure throttle 2 (P0 > packer setting pressure), the three rubber sleeves (inner rubber sleeve 105, steel strip skeleton 106, and outer rubber sleeve 107) of the expansion type high pressure packer 1 expand outward simultaneously, so that the outer rubber sleeve 107 fits with the inner wall of the casing to achieve the sealing of the upper and lower annular spaces of the rubber sleeve. At this time, the high pressure auxiliary sealing ring 110 moves upward under the action of pressure, pushing the second pressure ring 108 to squeeze the three rubber sleeves. The higher the pressure, the tighter the seal between the rubber sleeve and the casing, thus playing the role of high pressure auxiliary sealing. According to the construction needs, the pressure inside the oil pipe is gradually increased. Under the action of the adjustable constant pressure throttle 2, the pressure difference inside and outside the oil pipe always exists, ensuring that the expansion type high pressure packer 1 is always in the setting state. After the pressure inside the oil pipe rises to the leak-finding pressure, the pump is stopped and the pressure is stabilized for a preset time (e.g., 10 minutes). If there is no pressure drop, it indicates that there is no leak in the lower end of the packer sleeve.

[0107] The aforementioned constant-pressure throttle device adopts a ball-seat design, ensuring a constant pressure difference between the inside and outside of the tubing during pump shutdown and pressure stabilization operations for leak detection, thereby guaranteeing the sealing performance of the expandable high-pressure packer. Its adjustable pressure difference design allows for selection of the most suitable internal and external pressure difference for different packers, ensuring sealing performance while extending packer life. This device effectively solves the problem of accurate leak detection in horizontal and highly deviated sections of deep wells, making it highly suitable for widespread application.

[0108] In another alternative embodiment, refer to Figure 4 As shown, the constant pressure throttle 2 may further include a straightening ring 210 located between the first ball 208 and the first spring 207. In this embodiment, the straightening ring provides a straightening effect on both the spring and the ball to facilitate contact between them.

[0109] In another alternative embodiment, refer to Figure 4As shown, the central body 203 and the third connector 201 are welded together through the channel walls of the second fluid channel 211 and the third fluid channel 212. In this embodiment, the second fluid channel is formed by extending a portion outward from the opening on the central body to form the channel wall of the second fluid channel. The third fluid channel is directly formed by opening the opening on the third connector. The second fluid channel can be extended to the edge or inside of the third fluid channel for welding, so as to fix the central body and the third connector together.

[0110] In another alternative embodiment, refer to Figure 1 and Figure 4 As shown, the third connector 201 of the constant pressure throttle device 2 is threadedly connected to the second connector 111 of the high pressure packer 1;

[0111] And / or, the retaining ring 204 is threadedly connected to the upper part of the center body 203, and the ball seat 209 is threadedly connected to the lower part of the center body 203.

[0112] In this embodiment of the invention, the threaded connections between the various components are tighter, and assembly and disassembly are easier.

[0113] In another alternative embodiment, refer to Figure 6 As shown, the device may further include: a one-way valve assembly 3; the upper connector 301 of the one-way valve assembly 3 is detachably connected to the first connector 101 of the high-pressure packer 1 or the fourth connector 202 of the constant-pressure throttle 2.

[0114] The one-way valve assembly 3 in this embodiment of the invention is used to seal the oil pipe, thereby achieving pressure build-up when water is injected into the oil pipe, resulting in a pressure difference between the inside and outside of the oil pipe, and detecting leaks by measuring the pressure difference. In this embodiment, the one-way valve assembly is installed at the lowest (or farthest) end of the oil-water well leak detection device, and it can be connected to a high-pressure packer or the aforementioned constant-pressure throttle valve.

[0115] In another alternative embodiment, refer to Figure 3 As shown, the above-mentioned one-way valve assembly 3 may include: an upper connector 301, a sealing body 302, a coupling 303, a sand filter tube 304, a guide 305, a fixing plug 306, a second spring 307, a support plug 308, and a second ball 309.

[0116] One end of the sealing body 302 is detachably connected to the upper connector 301, and the other end is connected to one end of the sand filter pipe 304 via the coupling 303; the other end of the sand filter pipe 304 is connected to the guide 305.

[0117] The sealing body 302 has a hollow center, and the inner diameter of the portion of the sealing body 302 near the sand filter pipe 304 is smaller than the inner diameter of at least a portion of the portion away from the sand filter pipe 304. The second ball 309, the support plug 308, the second spring 307, and the fixing plug 306 are located in the hollow portion of the sealing body 302. The diameter of the second ball 309 is larger than the inner diameter of the portion of the sealing body 302 near the sand filter pipe 304. The fixing plug 306 is connected to the sealing body 302. The support plug 308 abuts against the second ball 309. The second spring 307 is located between the support plug 308 and the fixing plug 306. A fifth fluid channel 310 is provided on the fixing plug 306, and a sixth fluid channel 311 is provided on the support plug 308.

[0118] In this embodiment of the invention, one end of the sealing body 302 is preferably threadedly connected to the upper connector 301, and the other end of the sand filter pipe 304 is preferably threadedly connected to the guide 305. The sealing body 302 has a hollowed-out center to form a liquid cavity, allowing the support plug 308 and the second ball 309 to move up and down within the liquid cavity. When both are at their lowest points, the second spring 307 is in a free state. The fixing plug 306 is threadedly connected to the sealing body 302. The fifth fluid channel 310 on the fixing plug 306 and the sixth fluid channel 311 on the support plug 308 are large-diameter flow channels used for fluid injection during pressurization. The sand filter pipe 304 has numerous holes or slits to achieve filtration and sand control. The lower end of the guide 305 is tapered, facilitating its insertion into the casing or open hole well.

[0119] The working principle of this one-way valve assembly is as follows: The tubing carries the expandable high-pressure packer 1, the adjustable constant-pressure choke 2, and the one-way valve assembly 3 into the casing well (the side of the expandable high-pressure packer with the high-pressure sealing ring is close to the adjustable constant-pressure choke). Fluid enters the tubing from outside through the sand filter pipe and the one-way valve assembly, maintaining pressure balance, and is delivered to the predetermined leak location. During operation, a high-pressure pump pressurizes the tubing, and the fluid pushes the second ball 309 to seal the middle flow channel of the sealing body 302, causing the pressure inside the tubing to rise. When the pressure inside the tubing rises to the starting pressure P0 of the adjustable constant-pressure choke 2, the constant-pressure choke begins to throttle. After leak detection is completed, the pressure inside the tubing is released, and the fluid outside the tubing pushes the second ball 309 of the one-way valve assembly 3 upwards into the tubing space, causing the pressure difference between the inside and outside of the tubing to drop to zero. The three-layer rubber sleeve of the high-pressure packer—inner rubber sleeve, steel belt skeleton, and outer rubber sleeve—retracts due to its high elasticity and contractility, thus releasing the packer.

[0120] The oil and water well leakage detection device described in this embodiment of the invention is configured with different tubing string combinations according to operational requirements. Water is injected into the tubing at a predetermined depth to pressurize it. An adjustable pressure-regulating throttle with a ball-and-seat design generates an optimal internal and external pressure difference for the packer used (the pressure inside the tubing is 0.5–2 MPa higher than outside). Hydraulic pressure drives the expansion of the rubber sleeve to achieve sealing. During pressure stabilization, the pressure difference inside and outside the tubing remains constant, preventing leakage. The presence of a leakage point can be accurately determined by observing changes in tubing pressure. If a leakage point exists in the formation to be detected, fluid in the lower annulus of the rubber sleeve enters the formation through this leakage point, causing a decrease in the lower annulus pressure. The increased pressure difference inside and outside the tubing opens the fluid flow channel of the adjustable pressure-regulating throttle, allowing fluid inside the tubing to enter outside, thus reducing the tubing pressure.

[0121] Reference Figures 7-9 As shown, based on the needs of on-site leak detection operations, the tool assembly relationship of the above-mentioned oil and water well leak detection device can be divided into three types: bottom boundary detection, top boundary detection, and double-seal leak detection. The basic tool combination adopts "expansion-type high-pressure packer + adjustable constant-pressure throttle + one-way valve assembly". When detecting the bottom boundary, the adjustable constant-pressure throttle is placed on the upper end of the expansion-type high-pressure packer and connected to the tubing; when detecting the top boundary, the adjustable constant-pressure throttle is placed on the lower end of the expansion-type high-pressure packer and the packer is connected to the tubing; when double-seal leak detection in the middle, the adjustable constant-pressure throttle is placed between the two expansion-type high-pressure packers.

[0122] Taking the leak detection point as an example, during operation, a high-pressure packer 1, a constant-pressure throttle 2, and a one-way valve assembly 3 are lowered into the casing well using tubing (the side of the high-pressure packer with the high-pressure sealing ring is closer to the constant-pressure throttle). Fluid enters the tubing from outside through the sand filter pipe and the one-way valve assembly, maintaining pressure balance, and is delivered to the predetermined leak detection location. During operation, a high-pressure pump pressurizes the tubing, and the fluid pushes the second ball 309 of the one-way valve assembly 3 to block the middle flow channel of the sealing body 302, causing the pressure inside the tubing to rise. When the pressure inside the tubing rises to the starting pressure P0 of the constant-pressure throttle 2, hydraulic pressure pushes the first ball 208 and the centralizing ring 210 upward to compress the first spring 207. At this time, the first ball 208 separates from the ball seat 209, and the fluid enters the annulus outside the tubing through the fluid channels (the second fluid channel 211 and the third fluid channel 212), causing the pressure outside the tubing to rise. When the pressure P inside the tubing... 内 -P outside the pipe 外 When the starting pressure P0 is reached, the first ball 208 resets under the action of the first spring 207, sealing the ball seat 209 and closing the fourth fluid channel 213, thus reducing the internal and external pressure difference P. 内 -P 外The pressure is increased back to P0. The first ball 208 leaves the ball seat 209 and opens the fourth fluid channel 213. This process is repeated to keep the pressure difference between the inside and outside of the oil pipe at around P0. While the high-pressure pump pressurizes the oil pipe, the fluid enters the hydraulic chamber 112 between the central tube 102 and the inner rubber sleeve 105 through the first fluid channel 113 on the central tube 102 of the high-pressure packer 1. Under the action of the internal and external pressure difference P0 generated by the adjustable constant pressure throttle 2 (P0 > packer setting pressure), the three layers of rubber sleeves of the expansion type high-pressure packer 1, the inner rubber sleeve 105, the steel strip skeleton 106, and the outer rubber sleeve 107, expand outward simultaneously, so that the outer rubber sleeve 107 fits against the inner wall of the casing to achieve the sealing of the upper and lower annular spaces of the rubber sleeve. At this time, the high-pressure auxiliary sealing ring 110 moves upward under the action of pressure, pushing the second pressure ring 108 to squeeze the three layers of rubber sleeves. The higher the pressure, the tighter the seal between the rubber sleeve and the casing, thus playing the role of high-pressure auxiliary sealing. The pressure inside the tubing is gradually increased according to construction needs. Under the action of the adjustable constant pressure throttle 2, the pressure difference between the inside and outside of the tubing is always maintained, ensuring that the expansion-type high-pressure packer 1 is always in the set-sealing state. After the pressure inside the tubing rises to the leak-finding pressure, the pump is stopped and the pressure is stabilized for 10 minutes. If there is no pressure drop, it indicates that there is no leak in the lower end sleeve of the packer. The pressure inside the tubing is released, and the fluid outside the tubing pushes the second ball 309 of the one-way valve assembly 3 to move upward into the space inside the tubing, so that the pressure inside and outside the tubing drops to zero. The inner rubber sleeve 105, the steel belt skeleton 106, and the outer rubber sleeve 107 of the expansion-type high-pressure packer 1 retract under their own high elasticity and contractility, and the packer is unsealed. After moving the leak-finding tubing string upwards a certain distance, the pressure is repressurized, and the pressure change inside the tubing is observed during pressure stabilization. This process is repeated until a pressure drop occurs during pressure stabilization. The pressure drop indicates a leak in the lower casing of the packer. At this point, fluid in the lower annulus of the rubber sleeve enters the formation through this leak, causing a decrease in the lower annulus pressure. The increased pressure difference between the inside and outside of the tubing causes the fluid channels (second fluid channel 211 and third fluid channel 212) of the adjustable pressure throttle 2 to open, allowing fluid inside the tubing to enter the outside, thus reducing the tubing pressure. As described above, pressure is applied segment by segment from bottom to top, and the pressure change during pressure stabilization is observed to locate the bottom boundary of the leak section.

[0123] When locating the top boundary of the leak point, the adjustable constant pressure throttle 2 is located at the upper end of the expansion-type high-pressure packer 1. At the same time, the high-pressure auxiliary sealing ring 110 side of the expansion-type high-pressure packer 1 should be close to the adjustable constant pressure throttle 2. That is, in this leak-locating string, the high-pressure auxiliary sealing ring 110 side of the expansion-type high-pressure packer 1 is located at the upper end. Similarly, when locating leaks with two packers, the adjustable constant pressure throttle 2 is located between the two packers. The high-pressure auxiliary sealing ring 110 side of the upper packer is located at the lower end, and the high-pressure auxiliary sealing ring 110 side of the lower packer is located at the upper end. The leak-locating principle of both is the same as that of the bottom boundary of the leak point mentioned above. The embodiments of the present invention will not be described again here.

[0124] Based on the same inventive concept, this embodiment of the invention also provides an oil and water well leakage detection system, which may include: casing, water injection device, pressure detection device and the above-mentioned oil and water well leakage detection device.

[0125] Oil and water well leak detection devices are used to be inserted into the casing at the location to be detected;

[0126] The water injection device is used to inject water into the oil and water well leak detection device through the high-pressure pump and tubing of the water injection device;

[0127] The constant pressure throttle is used to keep the pressure difference between the inside and outside of the oil pipe constant after the high pressure pump stops injecting water;

[0128] High-pressure packers are set to seal the casing and tubing at the location to be tested;

[0129] Pressure detection devices are used to detect pressure changes in oil pipes.

[0130] Based on the same inventive concept, this embodiment of the invention also provides an application of the above-mentioned oil and water well leakage detection device in an oil and water well leakage detection system.

[0131] The specific descriptions and beneficial effects of the systems and applications provided in the embodiments of the present invention can be found in the section on packers and detection devices, and will not be repeated here.

[0132] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. This disclosure is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this disclosure is limited only by the appended claims. Thus, if these modifications and variations of the invention fall within the scope of the claims of the invention and their equivalents, the invention is also intended to include these modifications and variations.

Claims

1. A leak detection device for oil and water wells, characterized in that, include: A constant-pressure throttle and at least one high-pressure packer; The high-pressure packer includes: a first connector, a central tube, a first locking ring, a first pressure ring, an inner rubber cylinder, a steel strip skeleton, an outer rubber cylinder, a second pressure ring, a second locking ring, a high-pressure sealing ring, and a second connector; The first connector and the second connector are detachably connected to the central tube, respectively. The inner rubber sleeve is fitted outside the central tube, forming a hydraulic cavity between the inner rubber sleeve and the central tube. A first fluid channel communicating with the hydraulic cavity is provided on the central tube. The first locking ring is fitted outside the central tube, located between one end of the inner rubber sleeve and the central tube, and is limited by the end of the first connector. The second locking ring is fitted outside the central tube, located between the other end of the inner rubber sleeve and the central tube, and is limited by the end of the second connector. The steel strip skeleton is sleeved on the outside of the inner rubber cylinder, and the outer rubber cylinder is sleeved on the outside of the steel strip skeleton; the first pressure ring is sleeved on the outside of the first joint, the first locking ring, the inner rubber cylinder, and the steel strip skeleton; the high-pressure sealing ring is sleeved on the outside of the central tube, located between the second locking ring and the second joint; the second pressure ring is sleeved on the outside of the second locking ring, the inner rubber cylinder, the steel strip skeleton, and the high-pressure sealing ring; the first pressure ring is detachably connected to the first joint, and the second pressure ring is detachably connected to the high-pressure sealing ring; The constant pressure throttle includes: a third connector, a fourth connector, a central body, a fixing ring, a pressure adjusting shaft, a bearing tray, a first spring, a first ball, and a ball seat; The bottom of the third connector is detachably connected to the upper part of the fourth connector; The central body is cylindrical and is embedded inside the third connector, and is fixedly connected to the third connector; a second fluid channel is provided on the side wall of the third connector, and a third fluid channel corresponding to the second fluid channel is provided on the side wall of the central body; a fourth fluid channel is formed between the central body and the third connector and the hollowed-out part of the ball seat. The fixing ring is detachably connected to the upper part of the central body, and the ball seat is detachably connected to the lower part of the central body; the support plate is located below the fixing ring and is limited by the fixing ring; the first ball sits on the ball seat, and the first spring is located between the first ball and the support plate; the pressure adjusting shaft is threadedly connected to the fixing ring, and after the pressure adjusting shaft rotates, it abuts against the support plate to compress the first spring; the third connector is detachably connected to the second connector.

2. The oil and water well leakage detection device according to claim 1, characterized in that, A preset gap is reserved between the high-pressure sealing ring and the second locking ring.

3. The oil and water well leakage detection device according to claim 1, characterized in that, The outer side of the first locking ring is provided with a first annular groove; the outer side of the second locking ring is provided with a second annular groove; The inner side of the inner tube is provided with a first annular boss that matches the first annular groove and a second annular boss that matches the second annular groove. The outer side of the inner rubber cylinder is provided with a third annular boss and a fourth annular boss, the inner side of the first pressure ring is provided with a third annular groove that matches the third annular boss, and the inner side of the second pressure ring is provided with a fourth annular groove that matches the fourth annular boss.

4. The oil and water well leakage detection device according to any one of claims 1 to 3, characterized in that, The steel strip skeleton is glued and fixed to the inner rubber cylinder and the outer rubber cylinder respectively.

5. The oil and water well leakage detection device according to any one of claims 1 to 3, characterized in that, The first connector and the second connector are respectively threaded to the central pipe; And / or, The first pressure ring is threadedly connected to the first connector; And / or, The second pressure ring is threadedly connected to the high-pressure sealing ring.

6. The oil and water well leakage detection device according to any one of claims 1 to 3, characterized in that, The high-pressure packer further includes: a first sealing ring, a second sealing ring, and / or a third sealing ring; The outer side of the first connector is provided with a fifth annular groove, and the first sealing ring is located in the fifth annular groove; the first pressure ring is nested on the outer side of the first sealing ring; The high-pressure sealing ring has a sixth annular groove on its outer side, and the second sealing ring is located in the sixth annular groove; the second pressure ring is nested on the outside of the second sealing ring; The high-pressure sealing ring has a seventh annular groove on its inner side, and the third sealing ring is located in the seventh annular groove.

7. The oil and water well leakage detection device according to claim 1, characterized in that, The constant pressure throttle also includes a straightening ring located between the first ball and the first spring.

8. The oil and water well leakage detection device according to claim 1, characterized in that, The central body and the third connector are welded together through the channel walls of the second fluid channel and the third fluid channel.

9. The oil and water well leakage detection device according to claim 1, characterized in that, The third connector of the constant pressure throttle is threadedly connected to the second connector; And / or, the retaining ring is threadedly connected to the upper part of the central body, and the ball seat is threadedly connected to the lower part of the central body.

10. The oil and water well leakage detection device according to any one of claims 7 to 9, characterized in that, The constant pressure throttle also includes: a one-way valve assembly; the upper connector of the one-way valve assembly is detachably connected to the first connector of the high-pressure packer or the fourth connector of the constant pressure throttle.

11. The oil and water well leakage detection device according to claim 10, characterized in that, The one-way valve assembly includes: an upper connector, a sealing body, a coupling, a sand filter tube, a guide, a fixed plug, a second spring, a support plug, and a second ball; One end of the sealing body is detachably connected to the upper connector, and the other end is connected to one end of the sand filter tube via the coupling; the other end of the sand filter tube is connected to the guide. The sealing body has a hollow center, and the inner diameter of the portion of the sealing body near the sand filter pipe is smaller than the inner diameter of at least a portion of the portion away from the sand filter pipe; the second sphere, the support plug, the second spring, and the fixing plug are located in the hollow portion of the sealing body, the diameter of the second sphere is larger than the inner diameter of the portion of the sealing body near the sand filter pipe, and the fixing plug is connected to the sealing body; the support plug abuts against the second sphere, and the second spring is located between the support plug and the fixing plug; a fifth fluid channel is provided on the fixing plug, and a sixth fluid channel is provided on the support plug.

12. A leak detection system for oil and water wells, characterized in that, include: Casing, water injection device and pressure detection device and oil / water well leakage detection device as described in any one of claims 1 to 11; The oil and water well leakage detection device is used to be lowered into the casing at the location to be detected; The water injection device is used to inject water into the oil-water well leakage detection device through the high-pressure pump and oil pipe of the water injection device; The constant pressure throttle is used to keep the pressure difference inside and outside the oil pipe constant after the high pressure pump stops injecting water; The high-pressure packer is set to seal the casing and the tubing at the location to be tested; The pressure detection device is used to detect pressure changes in the oil pipe.

13. The application of the oil and water well leakage detection device as described in any one of claims 1 to 11 in an oil and water well leakage detection system.

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