Suspension Packer

Abstract

The present application provides a suspension packer, which relates to the field of oil extraction technology. The suspension packer includes: the outer part of the central pipe is sequentially sleeved with an upper power piston, an upper isolation ring, an upper piston, an upper slip, an upper cone, an upper rubber tube pressure ring, a sealing rubber tube, a lower rubber tube pressure ring, a lower cone, a lower slip, a lower piston, a lower isolation ring, and a lower power piston from the first joint to the second joint; wherein the first pressure transmission hole corresponds to the gap between the upper power piston and the first joint, the second pressure transmission hole corresponds to the gap between the upper isolation ring and the upper piston, the third pressure transmission hole corresponds to the gap between the lower piston and the lower isolation ring, and the fourth pressure transmission hole corresponds to the gap between the lower power piston and the second joint. The technical solution of the present application can realize the design of a two-way two-stage hydraulic cylinder suspension packer, which can be used in small-diameter wellbore conditions and can generate sufficient initial sealing force.

Description

Technical Field

[0001] The present application relates to the technical field of oil extraction, and in particular to a suspension packer. Background Art

[0002] In the production process of oil and gas fields, the segmented transformation technology of vertical wells or horizontal wells is an effective measure to increase production for the efficient development of low-permeability oil and gas reservoirs, ultra-low permeability, extra-low permeability, shale gas reservoirs and other unconventional oil and gas reservoirs. Due to the multi-layer system of vertical wells or the single-layer system of horizontal wells with long horizontal sections and strong heterogeneity, a one-time general acidification or fracturing is not very targeted and often cannot achieve the purpose of transformation. The use of open hole packers for segmented completion and transformation can take targeted transformation measures for each production layer, or increase the acid intensity or increase the scale of sand fracturing, so as to truly achieve the purpose of effectively removing near-well blockage and connecting reservoirs in each production layer.

[0003] The packer is one of the tools in the staged completion and transformation process. It plays a key role in completely separating the open hole reservoir from the upper casing and has been widely used. In the process of staged production enhancement of vertical or horizontal open hole completion, according to the geological transformation requirements, it is necessary to run a staged completion string to divide the open hole reservoir into several sections, run a packer at the corresponding position of the completion string, and run a sliding sleeve at the corresponding position that needs to be transformed (the fluid enters the reservoir through the sliding sleeve). When the completion string is lowered to the designed position, the packer is used for isolation, and the staged fracturing or acidizing production enhancement operation can be achieved.

[0004] Most of the existing suspended packer technologies adopt a one-way single-stage hydraulic cylinder structural design. Since the hydraulic cylinder action thrust of this type of suspended packer is relatively small, to complete the final sealing, it is necessary to use the weight of the pipe string to lift and press down, which requires high operator ability. Some suspended packers also adopt a two-way double-push hydraulic cylinder structure. This type of suspended packer can complete the complete sealing of the packer only by pressurizing the oil pipe, but it is generally suitable for larger casing. Summary of the invention

[0005] The purpose of the embodiment of the present application is to provide a suspension packer to realize a bidirectional two-stage hydraulic cylinder suspension packer design, which can be used in small diameter wellbore conditions and can generate sufficient initial sealing force.

[0006] In order to solve the above technical problems, the embodiments of the present application provide the following technical solutions:

[0007] The present application provides a suspension packer, which includes: a central tube, including a first end and a second end opposite to each other, and the central tube is provided with a radial first pressure transmission hole, a second pressure transmission hole, a third pressure transmission hole and a fourth pressure transmission hole in sequence from the first end to the second end; a first joint connected to the first end of the central tube; a second joint connected to the second end of the central tube; wherein the outer part of the central tube is provided with an upper power piston, an upper isolation ring, an upper piston, an upper slip, an upper cone, and an upper rubber tube pressure ring in sequence from the first joint to the second joint , sealing rubber cylinder, lower rubber cylinder pressure ring, lower cone, lower slip, lower piston, lower packing ring, lower power piston; wherein, the conical surfaces of the upper cone and the lower cone extend into the upper slip and the lower slip respectively, and the upper slip and the lower slip are fixed to the upper cone and the lower cone respectively by pins, and the upper cone, the upper packing ring and the lower packing ring are respectively fixedly connected to the axial direction of the center tube; an upper outer cylinder is sleeved on the outer sides of the upper power piston, the upper packing ring and the upper piston, and one end of the upper outer cylinder is connected to the first joint shaft by a plurality of first shear pins The first outer cylinder is fixed to the outside of the lower power piston, and the other end is axially fixed to the upper piston. The upper power piston is slidably and sealedly connected with the upper outer cylinder and the center tube respectively. The inner side of the upper outer cylinder has a first boss, and the upper power piston is pressed against the side of the first boss close to the first joint; the lower outer cylinder is sleeved on the outer side of the lower power piston, the lower sealing ring and the lower piston, and one end of it is axially fixed to the second joint through a plurality of second shear pins, and the other end of it is axially fixed to the lower piston, the lower power piston is slidably and sealedly connected with the lower outer cylinder and the center tube respectively, the inner side of the lower outer cylinder has a second boss, and the lower power piston is located on the side of the second boss close to the second joint, and the number of the second shear pins is less than the number of the first shear pins; wherein, the first pressure transmission hole corresponds to the gap between the upper power piston and the first joint, the second pressure transmission hole corresponds to the gap between the upper sealing ring and the upper piston, the third pressure transmission hole corresponds to the gap between the lower piston and the lower sealing ring, and the fourth pressure transmission hole corresponds to the gap between the lower power piston and the second joint.

[0008] In some modified embodiments of the present application, the inner surfaces of the upper piston and the lower piston respectively have a serrated cava tooth; the suspension packer also includes: a first locking cava, fixed to the center tube and having a serrated thread, for cooperating with the serrated cava tooth of the upper piston to limit the upper piston from sliding in a direction approaching the first joint; a second locking cava, fixed to the center tube and having a serrated thread, for cooperating with the serrated cava tooth of the lower piston to limit the lower piston from sliding in a direction approaching the second joint; wherein the number of the first locking cava and the second locking cava are two respectively.

[0009] In some modified embodiments of the present application, the inner surface of the lower cone has a serrated cava tooth; the suspension packer also includes: a third locking cava, fixed on the center pipe and having a serrated thread, for cooperating with the serrated cava tooth of the lower cone to limit the lower cone from sliding in a direction away from the sealing rubber tube.

[0010] In some modified embodiments of the present application, the first locking cava, the second locking cava and the third locking cava are respectively provided with circumferential openings; the center tube is provided with locking grooves that are compatible with the first locking cava, the second locking cava and the third locking cava; wherein the locking grooves from the first end to the second end of the center tube are respectively staggered at preset angles in the circumferential direction of the center tube.

[0011] In some modified implementations of the present application, the number of the first shear pins is 9; the number of the second shear pins is 6.

[0012] In some modified implementations of the present application, expandable metal cups are respectively provided on opposite sides of the sealing rubber tube.

[0013] In some modified implementations of the present application, a plurality of drain holes are respectively provided on the first boss and the second boss.

[0014] In some modified embodiments of the present application, the upper slip and the lower slip include: a large casing slip, having at least one groove and fixed to the upper cone by the pin; at least one small casing slip, installed in the groove and fixed to the large casing slip by a fixing screw; wherein the large casing slip is made of cast iron, and the small casing slip is made of bearing steel.

[0015] In some modified embodiments of the present application, the first connector is a female connector, and the second connector is a male connector.

[0016] In some modified implementations of the present application, a sealing groove is provided in the middle of the inner wall of the sealing rubber cylinder to accommodate a rubber cylinder support ring.

[0017] Compared with the prior art, the suspension packer provided in the present application can realize the function of a two-way two-stage hydraulic cylinder of the suspension packer by adopting the cooperation of two-stage pressure transmission holes and two-stage pistons in two directions. It can not only operate under small-diameter wellbore conditions, but also generate sufficient initial sealing force. It only needs to pressurize the oil pipe to the specified pressure to completely seal the suspension packer without additional operation. The operation method is simple and reliable. The upper and lower two-way hydraulic cylinders are started separately according to the step pressure, which brings controllability to the operation safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] By reading the detailed description below with reference to the accompanying drawings, the above and other purposes, features and advantages of the exemplary embodiments of the present application will become easy to understand. In the accompanying drawings, several embodiments of the present application are shown in an exemplary and non-limiting manner, and the same or corresponding reference numerals represent the same or corresponding parts, wherein:

[0019] Figure 1 A schematic diagram of a half-section structure of a main body of a suspension packer provided in an embodiment of the present invention is schematically shown;

[0020] Figure 2 A partial half-section structure diagram of a suspension packer proposed in an embodiment of the present invention is schematically shown;

[0021] Figure 3 Another partial half-section structure diagram of the suspension packer proposed in an embodiment of the present invention is schematically shown;

[0022] Figure 4 Another partial half-section structure diagram of the suspension packer proposed in an embodiment of the present invention is schematically shown;

[0023] Figure 5 The structural diagram of the central pipe of the suspension packer proposed in the embodiment of the present invention is schematically shown;

[0024] Figure 6 for Figure 5 Schematic diagram of the cross-sectional structure of the AA section;

[0025] Figure 7 for Figure 5 Schematic diagram of the cross-sectional structure of the middle BB section;

[0026] Figure 8 for Figure 5 Schematic diagram of the cross-sectional structure of the CC section;

[0027] Fig. 9 for Figure 5 Schematic diagram of the cross-sectional structure of the middle DD section;

[0028] Fig.10 The top view of the upper outer cylinder of the suspension packer proposed in the embodiment of the present invention is schematically shown;

[0029] Fig.11 for Fig.10 Schematic diagram of the cross-sectional structure of the AA section;

[0030] Fig.12 The schematic diagram of the top view of the structure of the first locking slip of the suspension packer proposed in the embodiment of the present invention is shown;

[0031] Fig.13 for Fig.12 Schematic diagram of the cross-sectional structure of the AA section;

[0032] Fig.14 for Fig.13 A partial enlarged structural diagram of the middle part;

[0033] Fig.15 The top view of the sealing rubber cylinder of the suspension packer proposed in the embodiment of the present invention is schematically shown;

[0034] Fig.16 for Fig.15 Schematic diagram of the cross-sectional structure of the AA section;

[0035] Fig.17 The schematic diagram of the top view of the expandable metal bowl of the suspension packer proposed in the embodiment of the present invention is shown;

[0036] Fig.18 for Fig.17 Schematic diagram of the cross-sectional structure of the AA section;

[0037] Fig.19 The top view of the structure of the retaining ring of the suspension packer proposed in the embodiment of the present invention is schematically shown;

[0038] Fig. 20 for Fig.19 Schematic diagram of the cross-sectional structure of the AA section;

[0039] Description of Figure Numbers:

[0040] Center tube 1, first pressure transmission hole 101, second pressure transmission hole 102, third pressure transmission hole 103, fourth pressure transmission hole 104, locking groove 105, upper cone threaded hole 106, retaining ring groove 107, first joint 2, second joint 3, upper power piston 4, upper sealing ring 5, upper piston 6, upper slip 7, upper cone 8, upper rubber cylinder pressure ring 9, sealing rubber cylinder 10, rubber cylinder groove 1001, lower rubber cylinder pressure ring 11, lower cone 12, lower slip 13, lower piston 14, lower sealing ring 15, lower power piston 16, upper outer cylinder 17, first boss 171, lower outer cylinder 18, first shear pin 19, second shear pin 20, emptying hole 21, first locking slip 22, second locking slip 23, third locking slip 24, expandable metal bowl 25, rubber cylinder support ring 26, serrated thread 27, retaining ring 28. DETAILED DESCRIPTION

[0041] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0042] It should be noted that, unless otherwise specified, the technical terms or scientific terms used in this application should have the common meanings understood by technicians in the field to which this application belongs.

[0043] In the prior art, most of the suspended packers adopt a single-stage hydraulic cylinder structure design. After the hydraulic cylinder is activated, this type of suspended packer can only complete the initial sealing due to the small thrust. To complete the final sealing, the weight of the pipe string is required to perform lifting and pressing operations, which requires high operator ability. If the pipe string diameter is small, the pipe string is prone to bending, causing failure and other problems. Some suspended packers also adopt a two-way double-push hydraulic cylinder structure. This type of suspended packer can complete the sealing of the packer only by pressurizing the oil pipe. However, because it only has a one-way and single-stage hydraulic cylinder, the thrust generated is less limited by the inner and outer diameter dimensions, and is generally suitable for larger series.

[0044] As the development of oil and gas wells becomes increasingly difficult, there is a need to drill horizontal wells by opening windows in casings of 5-1 / 2", 5" and below. The existing suspension packer structure can no longer meet the applicable conditions. In order to increase the hydraulic sealing force, the present invention adopts a new type of bidirectional two-stage hydraulic cylinder design to solve the above technical problems.

[0045] Embodiment 1

[0046] Reference Figure 1 -Attached Fig. 20 Embodiment 1 of the present invention proposes a suspension packer, which is a bidirectional two-stage hydraulic cylinder suspension packer, and its structure specifically includes: a central pipe 1, including a first end and a second end opposite to each other, and the first end and the second end are respectively connected with a first joint 2 and a second joint 3; wherein the first joint 2 can be a female joint, which is located at the upper end during operation and is used to connect the male thread of the seat seal release tool; the second joint 3 can be a male joint, which is located at the lower end during operation and is used to connect the female thread of the upper end of the completion string that has entered the well.

[0047] For details, please refer to the attached Figure 5 and attached Figure 6The center tube 1 is made of 42CrMo / 35CrMo alloy steel material, and its outer surface is required to be surface treated by cold rolling to meet the requirements of wear resistance and high finish; the first end and the second end of the center tube 1 can be respectively provided with 60-degree oil pipe buckles to connect the first joint 2 and the second joint 3. Due to the increase in the buckling torque, the center tube 1 can be prevented from loosening, and the use of sealing rings can be omitted, thereby reducing the risk of leakage.

[0048] For further information, see Attachment Figure 1 -Attached Figure 4 In order to realize bidirectional sealing, the outer part of the central tube 1 is sequentially sleeved with an upper power piston 4, an upper sealing ring 5, an upper piston 6, an upper slip 7, an upper cone 8, an upper rubber tube pressure ring 9, a sealing rubber tube 10, a lower rubber tube pressure ring 11, a lower cone 12, a lower slip 13, a lower piston 14, a lower sealing ring 15, and a lower power piston 16 from the first joint 2 to the second joint 3; wherein the conical surfaces of the upper cone 8 and the lower cone 12 extend into the upper slip 7 and the lower slip 13 respectively, and the upper slip 7 and the lower slip 13 are fixed to the upper cone 8 and the lower cone 12 respectively by pins, and the upper cone 8 can be axially fixedly connected to the central tube 1 by a fixing pin, correspondingly, refer to the attached Figure 5 And attached Figure 7 -Attached Fig. 9 , an upper cone threaded hole 106 should be provided on the center pipe 1. In order to increase the strength of the center pipe 1, the upper cone threaded holes 106 can be arranged in two rows, and each row is provided with 3 upper cone threaded holes 106 and the angles are staggered with each other; the lower isolation ring 15 is axially fixed to the center pipe 1 by a threaded connection; refer to the attached Figure 2 , Attachment Fig.19 And attached Fig. 20 In order to achieve axial fixation of the upper isolation ring 5 and the center tube 1, two retaining ring grooves 107 corresponding to the upper isolation ring 5 can be set on the center tube 1 to accommodate two retaining rings 28, so as to achieve positioning and limiting of the upper isolation ring 5 through the two retaining rings 28. The retaining ring 28 here can be a special elastic retaining ring for the shaft.

[0049] For further information, see Attachment Figure 1 -Attached Figure 4In order to realize the bidirectional two-stage hydraulic cylinder structure, the suspension packer proposed in this embodiment further includes an upper outer cylinder 17 and a lower outer cylinder 18; wherein, the upper outer cylinder 17 is sleeved on the outer sides of the upper power piston 4, the upper isolation ring 5 and the upper piston 6, and one end thereof can be axially fixed to the first joint 2 through 9 first shear pins 19, and the other end thereof is axially fixed to the upper piston 6 through a connecting pin, the upper power piston 4 is slidably and sealingly connected to the upper outer cylinder 17 and the central pipe 1 respectively, and the inner side of the upper outer cylinder 17 has a first boss 171, the upper power piston 4 is held against the side of the first boss 171 close to the first joint 2; the lower outer tube 18 is sleeved on the outer sides of the lower power piston 16, the lower sealing ring 15 and the lower piston 14, and one end of the lower power piston 16 can be axially fixed to the second joint 3 through 6 second shear pins 20, and the other end of the lower power piston 16 can be axially fixed to the lower piston 14 through a connecting pin, the lower power piston 16 is slidably and sealedly connected to the lower outer tube 18 and the central tube 1 respectively, the inner side of the lower outer tube 18 has a second boss, the The lower power piston 16 is located on the side of the second boss close to the second joint 3, and the number of the second shear pins 20 is less than the number of the first shear pins 19; the first boss 171 and the second boss are respectively provided with a plurality of drain holes 21; wherein the central tube 1 is provided with radial first pressure transmission holes 101, second pressure transmission holes 102, third pressure transmission holes 103 and fourth pressure transmission holes 104 in sequence from the first end to the second end, and the first pressure transmission holes 101 correspond to the upper power piston 4 and the first joint 3; The second pressure transmission hole 102 corresponds to the gap between the upper isolation ring 5 and the upper piston 6. Therefore, the first pressure transmission hole 101 and the second pressure transmission hole 102 can realize a two-stage hydraulic cylinder in the first direction, the third pressure transmission hole 103 corresponds to the gap between the lower piston 14 and the lower isolation ring 15, and the fourth pressure transmission hole 104 corresponds to the gap between the lower power piston 16 and the second joint 3. Similarly, the third pressure transmission hole 103 and the fourth pressure transmission hole 104 can realize a two-stage hydraulic cylinder in the second direction.

[0050] For details, please refer to the attached Fig.10 and attached Fig.11 , is a schematic diagram of the structure of the upper outer cylinder 17. The lower outer cylinder 18 has the same structure as the upper outer cylinder 17 and is symmetrically arranged during installation. Both ends of the upper outer cylinder 17 and the lower outer cylinder 18 are chamfered at 15 degrees to facilitate the installation of the upper power piston 4 and the lower power piston 16; a plurality of shear pin mounting holes are set at one end of the upper outer cylinder 17 and the lower outer cylinder 18, and a connecting pin mounting hole is set at the other end; the inner hole finish of the upper outer cylinder 17 and the lower outer cylinder 18 is 1.6μm.

[0051] Specifically, through the bidirectional two-stage hydraulic cylinder design, the lower power piston 16 is against the lower side of the second boss. When the second hydraulic cylinder is started, the third pressure transmission hole 103 and the fourth pressure transmission hole 104 can work together to transmit pressure, so that the upper power piston 4 and the upper piston 6 move up together to complete the initial suspension action; the upper power piston 4 is against the upper side of the first boss 171. When the first hydraulic cylinder is started, the first pressure transmission hole 101 and the second pressure transmission hole 102 can work together to transmit pressure, so that the lower power piston 16 and the lower piston 14 move down together to complete the sealing of the entire hanger; therefore, the bidirectional two-stage hydraulic cylinder design is adopted, and the small tool diameter can meet the pressure transmission requirements, thereby realizing operation under small diameter wellbore conditions, so that the sealing operation is no longer limited by the wellbore diameter. The upper outer cylinder 17 and the lower outer cylinder 18 are designed in an integrated manner, and there is no threaded connection between the upper power piston 4 and the upper piston 6, and between the lower power piston 16 and the lower piston 14, so that the risk of the tool being disengaged during the lowering process can be effectively reduced. It should be noted that the above-mentioned sealing connection can be achieved by setting a sealing groove on the corresponding structure and cooperating with an O-ring. For example, a sealing groove can be opened at the inner upper end and the outer lower end of the lower piston 14, and an O-ring can be set in the sealing groove to achieve a sealed connection between the lower piston 14 and the center tube 1 and the upper outer tube 17.

[0052] Specifically, before using the hanging packer proposed in this embodiment to perform the sealing operation: first connect the second joint 3 at the lower end of the hanging packer to the upper end of the completion tubing that has been lowered into the well, which can be connected by threaded connection, and tightened according to the specified torque; connect the upper end of the hanging packer to the sealing release tool, which can also be connected by threaded connection, and tightened according to the specified torque; lower the connected hanging packer into the predetermined sealing position in the oil and gas well casing, and when the wellbore isolation valve or shear ball seat provided at the lower part of the tubing is started, the sealing of the hanging packer is completed by step-by-step pressure operation in the oil pipe.

[0053] Specifically, the process of using the suspension packer proposed in this embodiment to seal is as follows: when the pressure starts to be applied inside, the pressure will act on the upper and lower double-stage hydraulic cylinders of the tool through the first pressure transmission hole 101, the second pressure transmission hole 102, the third pressure transmission hole 103 and the fourth pressure transmission hole 104, the lower power piston 16 and the lower piston 14 jointly push the lower outer cylinder 18 to move upward, and the upper power piston 4 and the upper piston 6 jointly push the upper outer cylinder 17 to move downward. Since the number of the first shear pins 19 used to connect the upper outer cylinder 17 with the first joint 2 is greater than the number of the second shear pins 2 used to connect the lower outer cylinder 18 with the second joint 3, 0, therefore, when the pressure reaches the predetermined first stage pressure (the first stage pressure is generally set to about 11-12MPa), the second shear pin 20 connected to the lower outer tube 18 is shortened, and the lower hydraulic cylinder is started first. After the second shear pin 20 is cut off, the pressure in the oil pipe will drop from 12MPa to about 2-3MPa; after the lower hydraulic cylinder is started, the lower piston 14 pushes the lower slip 13, the lower cone 12, the lower rubber cylinder pressure ring 11 and the sealing rubber cylinder 10 to move upward. Since the upper cone 8 is axially fixed to the center tube 1 and cannot move, the sealing rubber cylinder 10 and the lower rubber cylinder pressure ring 11 are pressed upward. The ring 11 can no longer move upward, so that the sealing rubber sleeve 10 is compressed, causing the sealing rubber sleeve 10 to swell and fit tightly against the inner wall of the casing to achieve a preliminary seal; the oil pipe pressure is increased to 12MPa again, and the lower piston 14 will crush the lower slip 13 according to the set groove (the preset crushing force is 6-8MPa) and expand it to the inner wall of the casing, and the teeth of the lower slip 13 will be slightly embedded in the inner wall of the casing to complete the preliminary suspension action; continue to increase the pressure in the oil pipe to the second stage pressure (the second stage pressure is generally set to about 18-19MPa), and the first shear pin connected to the upper outer cylinder 17 and the first joint 2 After the nail 19 is cut off, the upper hydraulic cylinder will start, and then the upper slip 7 will be crushed and expanded according to the set groove, so that the teeth of the upper slip 7 are slightly embedded in the inner wall of the casing, completing the initial sealing of the entire hanger; at this time, the casing annulus sealing performance can be tested (generally 15MPa, pressure maintenance for 15 minutes). When the pressure test is qualified, the release operation can be performed. At this time, the tubing pressure will rise to the third stage pressure (the third stage pressure is generally set to about 24-25MPa), and the suspension packer will complete the final sealing, and can fully achieve the required annulus sealing capacity (generally required to be above 50MPa).

[0054] According to the above, an embodiment of the present invention proposes a suspension packer, which can realize the function of a two-way two-stage hydraulic cylinder type of the suspension packer by adopting a two-stage pressure transmission hole and a two-stage piston in both directions. It can not only operate under small-diameter wellbore conditions, but also generate sufficient initial sealing force. It only needs to pressurize the oil pipe to the specified pressure to completely seal the suspension packer without additional operation, and the operation method is simple and reliable; and the upper and lower two-way hydraulic cylinders are started separately according to the step pressure, which brings controllability to the operation safety.

[0055] For further information, see Attachment Figure 2 and attached Figure 4 In a specific implementation, the inner surfaces of the upper piston 6 and the lower piston 14 respectively have serrated cava teeth; and the suspension packer provided in this embodiment also includes: a first locking cava 22, fixed on the central pipe 1 and having a serrated thread 27, for cooperating with the serrated cava teeth of the upper piston 6 to limit the upper piston 6 from sliding in a direction close to the first joint 2; a second locking cava 23, fixed on the central pipe 1 and having a serrated thread 27, for cooperating with the serrated cava teeth of the lower piston 14 to limit the lower piston 14 from sliding in a direction close to the second joint 3; wherein the number of the first locking cava 22 and the second locking cava 23 are two respectively.

[0056] Specifically, in order to avoid the reverse movement of the upper piston 6 and the lower piston 14 during the sealing process and affect the sealing effect, in the technical solution adopted by the present invention, a first locking cava 22 and a second locking cava 23 are fixed on the center tube 1, and their positions correspond to the upper piston 6 and the lower piston 14 respectively. The first locking cava 22 and the second locking cava 23 have serrated threads respectively, and the inner surfaces of the upper piston 6 and the lower piston 14 have toothed cava teeth respectively, and the serrated threads 27 of the first locking cava 22 are arranged in the same direction as the toothed cava teeth of the upper piston 6, and are oriented downward, thereby limiting the upper piston 6 from moving upward, that is, in a direction close to the first joint 2; and the serrated threads 27 of the second locking cava 23 are arranged in the same direction as the toothed cava teeth of the lower piston 14, and are oriented upward, thereby limiting the lower piston 14 from moving downward, that is, in a direction close to the second joint 3.

[0057] For further information, see Attachment Figure 3 In a specific implementation, the inner surface of the lower cone 12 has a serrated cava tooth; the suspension packer also includes: a third locking cava 24, which is fixed on the central pipe 1 and has a serrated thread 27, and is used to cooperate with the serrated cava tooth of the lower cone 12 to limit the lower cone 12 from sliding in a direction away from the sealing rubber tube 10.

[0058] Specifically, in order to prevent the lower cone 12 from moving backward during the sealing process and affecting the sealing effect, in the technical solution adopted by the present invention, a third locking cava 24 is fixed on the center tube 1, and the position corresponds to the lower cone 12. The third locking cava 24 has a serrated thread, and the lower cone 12 has a serrated cava tooth. By configuring the serrated thread 27 of the third locking cava 24 to be in the same direction as the serrated cava tooth of the lower cone 12, which is directed upward, the lower cone 12 can be restricted from moving downward, that is, in the direction close to the second joint 3. Even if the lower cava 13 fails, the sealing rubber sleeve 10 can still maintain an inflated sealing state to ensure the sealing effect.

[0059] For further information, see Attachment Figure 5 And attached Fig.12 -Attached Fig.14 In a specific implementation, the first locking slip 22, the second locking slip 23 and the third locking slip 24 are respectively provided with circumferential openings; the center pipe 1 is provided with locking grooves 105 adapted to the first locking slip 22, the second locking slip 23 and the third locking slip 24; wherein the locking grooves 105 from the first end to the second end of the center pipe 1 are respectively staggered at preset angles in the circumferential direction of the center pipe 1.

[0060] Specifically, in order to facilitate the installation of the first locking slip 22, the second locking slip 23 and the third locking slip 24 and to improve the strength of the central pipe 1, in the technical solution adopted by the present invention, the structures of the first locking slip 22, the second locking slip 23 and the third locking slip 24 are the same, as shown in the attached drawings. Fig.12 -Attached Fig.14 The first locking slip 22, the second locking slip 23 and the third locking slip 24 have openings respectively, which can facilitate the first locking slip 22, the second locking slip 23 and the third locking slip 24 to be assembled into the locking groove 105 of the central tube 1, and the locking grooves 105 from the first end to the second end of the central tube 1 can be further arranged to be staggered 90 degrees in the circumferential direction of the central tube 1 to improve the overall cavity of the central tube 1. The first locking slip 22, the second locking slip 23 and the third locking slip 24 can be processed by 65Mn or 60Si2Mn spring steel materials, and refer to the attached Fig.14 The climbing angle b of the serrated thread configured on the first locking slip 22, the second locking slip 23 and the third locking slip 24 can be set to 60 degrees, and the locking angle a is configured to -3 degrees, thereby ensuring the reliability of locking.

[0061] For further information, see Attachment Fig.17 and attached Fig.18 In a specific implementation, the two opposite sides of the sealing rubber tube 10 are respectively provided with expandable metal cups 25.

[0062] Specifically, in order to improve the sealing performance of the sealing rubber tube 10, in the technical solution adopted by the present invention, the expandable metal bowl 25 can be made of 10 steel, and the mouth has a 45° thin edge of 1-1.5mm, which is sleeved on both sides of the sealing rubber tube 10. After compression and expansion, it can fit tightly with the inner wall of the sleeve to protect the sealing of the sealing rubber tube 10.

[0063] For further information, see Attachment Figure 1In a specific implementation, the upper slip 7 and the lower slip 13 include: a large casing slip, having at least one groove, and fixed to the upper cone 8 by the pin; at least one small casing slip, installed in the groove, and fixed to the large casing slip by a fixing screw; wherein the material of the large casing slip is cast iron, and the material of the small casing slip is bearing steel.

[0064] Specifically, the slips need to be broken under the push and squeeze of the piston. At this time, the piston is fixed by the locking device, so that the suspension packer is anchored on the casing. During the fracturing construction process, the pipe string will vibrate continuously, so the slips are required to be fragile, hard and wear-resistant. In the technical solution adopted by the present invention, the upper slip 7 and the lower slip 13 adopt an inlay structure, including a large casing slip and at least one small casing slip sleeved on the outside of the large casing slip. Specifically, one large casing slip can be configured with 6 small casing slips; the hardness of the small casing slip after heat treatment is much greater than the hardness of the casing and the hardness of cast iron. When designing, the small casing slip is kept slightly higher than the surface of the large casing slip shell. In the overall design of the suspension packer, the outer diameter of the slip is generally smaller than the maximum outer diameter of the tool. Therefore, if the large casing slip is not squeezed and broken by the push ring next to it, that is, the slope surface, the small casing slip cannot touch the casing. The large casing slip is assembled on the push ring of the suspension packer. When the entire suspension packer is not working, the large casing slip cannot touch the casing; when the suspension packer is working, the movement of the piston causes the large casing slip to break through squeezing, and the small casing slip will also be squeezed and broken when it contacts the casing wall. The ruptured large casing slip expands to all sides to ensure that the small casing slip contacts the casing wall first, so that the suspension packer mainly relies on the small casing slip to anchor the casing. Since the small casing slips are made of Gr15 (bearing steel), the upper slip 7 and the lower slip 13 can engage with the casing wall to a deeper depth when the suspended packer is working. At the same time, good wear resistance is guaranteed when the pipe string vibrates during acid fracturing and production increase construction, which provides a strong guarantee for acid fracturing and production increase construction and greatly reduces the construction risk. Therefore, it has the advantages of fragility, high hardness and wear resistance.

[0065] For further information, see Attachment Fig.15 and attached Fig.16 In a specific implementation, a rubber sleeve groove 1001 is provided in the middle of the inner wall of the sealing rubber sleeve 10 to accommodate the rubber sleeve support ring 26 .

[0066] Specifically, in order to improve the sealing reliability of the sealing rubber sleeve 10, in the technical solution adopted by the present invention, a rubber sleeve groove 1001 can be set in the middle of the inner wall of the sealing rubber sleeve 10, and a rubber sleeve support ring 26 can be installed in the rubber sleeve groove 1001, so that when the sealing rubber sleeve 10 is compressed, it can begin to deform according to the set position to ensure the sealing reliability; refer to the attached Fig.16The angle c of the rubber sleeve groove 1001 can be set to 45 degrees; the sealing rubber sleeve 10 can be made of hydrogenated nitrile or AFLAS material.

[0067] Specifically, the installation method of the suspension packer proposed in this embodiment is as follows: install 6 small casing slips into the corresponding grooves of a large casing slip respectively, and tighten them by fixing screws to form an upper slip 7 structure; similarly, install 6 small casing slips into the corresponding grooves of another large casing slip respectively, and tighten them by fixing screws to form a lower slip 13 structure; connect the installed upper slip 7 with the upper cone 8, so that the conical surface of the large casing slip of the upper slip 7 matches the conical surface of the upper cone 8, and the threaded holes are aligned, and use 3 large casing slips to fix the small pins to fix it with the upper cone 8 and screw it to a suitable position; connect the installed lower slip 13 with the lower cone 12, so that the large casing slip The conical surface of the tile matches the conical surface of the lower cone 12, the threaded holes are aligned, and three large sleeve slips are used to fix the small pins to fix it to the lower cone 12 and screw it to the appropriate position; install the rubber tube support ring 26 into the groove in the sealing rubber tube 10, install an O-ring into the sealing groove of the rubber tube support ring 26, install two expandable metal bowls 25 into place from both ends of the sealing rubber tube 10, and install the upper rubber tube pressure ring 9 and the lower rubber tube pressure ring 11 into place from both ends of the sealing rubber tube 10; install O-rings in the two sealing grooves on the inner and outer sides of the lower packing ring 15, and evenly apply 1# lithium-based grease, and then install it from the upper end of the center tube 1 to make the lower packing The internal thread of the ring 15 is connected to the external triangular thread on the right side of the center tube 1 and tightened; then install the two second locking slips 23 into the two grooves on the lower side of the center tube 1, requiring the serrated thread of the second locking slip 23 to face downward, install the two O-rings into the sealing groove at the upper end of the inner side of the lower piston 14, and install the lower piston 14 from the upper side of the center tube 1. When the lower piston 14 reaches the position of the second locking slip 23, it needs to be rotated and installed until it stops at the position of the third pressure transmission hole 103; then install the two O-rings into the sealing groove on the outer side of the right end of the lower piston 14, and install the 17 lower outer tube 18 from the lower side of the center tube 1, so that its upper end surface is aligned with the upper end of the lower piston 14 Hold it up, use 6 connecting pins to install into the left threaded hole on the lower outer tube 18 to fix the lower outer tube 18 to the lower piston 14; install O-rings on the sealing grooves on the inner and outer sides of the lower power piston 16 respectively, and evenly apply 1# lithium-based grease, and then install the lower power piston 16 from the bottom side of the center tube 1 until the fourth pressure transmission hole 104 is exposed; install 2 O-rings into the sealing groove on the outer side of the upper end of the second joint 3, connect the second joint 3 with the male buckle on the lower side of the center tube 1, tighten it according to the required torque, install 6 shear pins into the threaded holes on the lower side of the lower outer tube 18, and fix the second joint 3 to the lower outer tube 18; at this point, the lower cylinder part is assembled.

[0068] Then install a third locking slip 24 into the middle groove of the center tube 1, requiring the sawtooth thread of the third locking slip 24 to face downward, and install the assembled lower cone 12 and lower slip 13 from the upper side of the center tube 1. The lower cone 12 is installed into the third locking slip 24, and it needs to be rotated to continue to be installed. When the distance between the lower side end face of the large sleeve slip of the upper slip 7 and the upper end face of the lower piston 14 is 5-7mm, it is in place; install the assembled sealing rubber cylinder 10, the expandable The metal bowl 25 and the rubber sleeve pressure ring assembly are installed from the upper side of the center tube 1 so that they are close to the lower cone 12; the assembled upper cone 8 and upper slip 7 are installed from the upper side of the center tube 1 so that they are close to the rubber sleeve pressure ring, and the threaded hole of the upper cone 8 is aligned with the threaded hole of the center tube 1, and then the upper cone 8 is fixed to the center tube 1 with 6 fixing pins; the two first locking slips 22 are respectively installed in the two grooves on the upper side of the center tube 1, and the first locking slips 22 are required to be fixed to the center tube 1. The sawtooth threads of the slips 22 are all facing upwards, and O-rings are installed in the sealing grooves on both sides of the upper piston 6. Then the upper piston 6 is installed from the upper side of the center tube 1. When the distance between the upper piston 6 and the upper end face of the large sleeve slip of the upper slip 7 is 5-7mm and the second pressure transmission hole 102 is exposed, a special shaft elastic retaining ring is installed from the upper side of the center tube 1 into the elastic retaining ring groove on the lower side, and the sealing grooves on both sides of the upper packing ring 5 are sealed. O-rings are installed in the grooves respectively, and then the upper sealing ring 5 is installed from the upper side of the central tube 1 so that its lower side surface is in close contact with the special shaft elastic retaining ring, and then another special shaft elastic retaining ring is installed from the upper side of the central tube 1 into the upper elastic retaining ring groove, and the upper outer tube 17 is installed from the upper side of the central tube 1 so that its lower end surface is in close contact with the upper piston 6, and then 6 connecting pins are installed into the threaded holes on the right side of the upper outer tube 17 to fix the upper outer tube 17 to the upper piston 6. Install O-rings on the sealing grooves on the inner and outer sides of the upper power piston 4 respectively, and evenly apply 1# lithium-based grease, then install the upper power piston 4 from the upper side of the central tube 1 until the first pressure transmission hole 101 is exposed; install an O-ring in the sealing groove on the outer side of the right end of the first joint 2, connect the first joint 2 with the male buckle on the upper side of the central tube 1, and tighten it according to the required torque, install 9 shear pins into the threaded holes on the upper side of the upper outer tube 17, and fix the first joint 2 with the upper outer tube 17; at this point, the assembly of the suspension packer is completed.

[0069] It should be noted that in the description of this specification, the terms "upper", "lower", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, which is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention; the terms "connect", "install", "fixed", etc. should be understood in a broad sense, for example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0070] In the description of this specification, the description of the terms "one embodiment", "some embodiments", "specific embodiments", etc. 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 representation of the above terms does 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.

[0071] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A suspension packer, characterized in that: include: A central tube, comprising a first end and a second end opposite to each other, and a first pressure transmission hole, a second pressure transmission hole, a third pressure transmission hole and a fourth pressure transmission hole are sequentially arranged in radial direction on the central tube from the first end to the second end; a first joint connected to the first end of the central tube; a second joint connected to the second end of the central tube; The outer part of the central tube is provided with an upper power piston, an upper packing ring, an upper piston, an upper slip, an upper cone, an upper rubber tube pressure ring, a sealing rubber tube, a lower rubber tube pressure ring, a lower cone, a lower slip, a lower piston, a lower packing ring, and a lower power piston in sequence from the first joint to the second joint; The conical surfaces of the upper cone and the lower cone extend into the upper slip and the lower slip respectively, and the upper slip and the lower slip are fixed to the upper cone and the lower cone respectively by pins, the upper cone, the upper packing ring and the lower packing ring are respectively axially fixedly connected to the central tube, the inner surfaces of the upper piston and the lower piston are respectively provided with toothed slip teeth, and the opposite sides of the sealing rubber tube are respectively provided with expandable metal bowls; An upper outer cylinder is sleeved on the outer sides of the upper power piston, the upper sealing ring and the upper piston, and one end of the upper outer cylinder is axially fixed to the first joint through a plurality of first shear pins, and the other end of the upper outer cylinder is axially fixed to the upper piston. The upper power piston is slidably and sealingly connected to the upper outer cylinder and the center tube respectively. The inner side of the upper outer cylinder has a first boss, and the upper power piston is abutted against a side of the first boss close to the first joint; A lower outer cylinder is sleeved on the outer sides of the lower power piston, the lower sealing ring and the lower piston, and one end of the lower outer cylinder is axially fixed to the second joint through a plurality of second shear pins, and the other end of the lower outer cylinder is axially fixed to the lower piston, the lower power piston is slidingly and sealingly connected to the lower outer cylinder and the center tube respectively, the inner side of the lower outer cylinder has a second boss, the lower power piston is located on the side of the second boss close to the second joint, and the number of the second shear pins is less than the number of the first shear pins; Wherein, the first pressure transmission hole corresponds to the gap between the upper power piston and the first joint, the second pressure transmission hole corresponds to the gap between the upper packing ring and the upper piston, the third pressure transmission hole corresponds to the gap between the lower piston and the lower packing ring, and the fourth pressure transmission hole corresponds to the gap between the lower power piston and the second joint; A first locking slip, fixed on the central tube and having a sawtooth thread, for cooperating with the toothed slip teeth of the upper piston to limit the upper piston from sliding in a direction close to the first joint; A second locking slip, fixed on the central tube and having a sawtooth thread, for cooperating with the toothed slip teeth of the lower piston to limit the lower piston from sliding in a direction close to the second joint; There are two first locking slips and two second locking slips, respectively.

2. The suspension packer according to claim 1, characterized in that: The inner surface of the lower cone has tooth-shaped slip teeth; The suspension packer also includes: The third locking slip is fixed on the central tube and has a sawtooth thread, and is used to cooperate with the toothed slip teeth of the lower cone to limit the sliding of the lower cone in a direction away from the sealing rubber cylinder.

3. The suspension packer according to claim 2, characterized in that: The first locking slip, the second locking slip and the third locking slip are respectively provided with circumferential openings; The central pipe is provided with locking grooves adapted to the first locking slip, the second locking slip and the third locking slip; Wherein, the locking grooves from the first end to the second end of the central tube are staggered at preset angles in the circumferential direction of the central tube.

4. The suspension packer according to claim 1, characterized in that: The number of the first shear pins is 9; The number of the second shear pins is 6.

5. The suspension packer according to claim 1, characterized in that: A plurality of drain holes are respectively disposed on the first boss and the second boss.

6. The suspension packer according to claim 1, characterized in that: The upper slip and the lower slip include: A large casing slip having at least one groove and fixed to the upper cone by the pin; At least one small casing slip is installed in the groove and fixed to the large casing slip by fixing screws; Among them, the material of the large casing slip is cast iron, and the material of the small casing slip is bearing steel.

7. The suspension packer according to claim 1, characterized in that: The first connector is a female connector, and the second connector is a male connector.

8. The suspension packer according to claim 1, characterized in that: A sealing groove is provided in the middle of the inner wall of the sealing rubber cylinder to accommodate the rubber cylinder support ring.

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