Anchor for oil well casing

Abstract

The invention relates to the technical field of anchors, and discloses an anchor for an oil well casing, the anchor comprises a pressurizing mechanism, the pressurizing mechanism comprises a piston I, a piston II, a spring I and a connector, the piston I is sleeved on the inner wall of a transmission cavity in a sealing manner, and the piston II is sleeved on the inner wall of a pressurizing cavity in a sealing manner; hydraulic oil is filled between the first piston and the pressurizing cavity and in an inner cavity of the oil inlet cavity, and the sectional area of the first piston is smaller than that of the second piston. According to the device, the inclined faces between the driving block and the driven block abut against each other, the outer supporting type anchoring function of the driven block and the outer attaching plate is achieved, the pressure of the second piston is amplified by multiple times through the first piston, and therefore the second piston pushes the driven block downwards through the connector and the driving block to conduct outer supporting motion very easily; and the implementation structure is mainly composed of several groups of sealed spaces which are communicated with one another, namely the oil inlet cavity, the transmission cavity and the pressurizing cavity, and the reliability is high.

Description

Technical Field

[0001] The present application relates to the technical field of anchors, and in particular to an anchor for oil well casing. Background Art

[0002] Anchor is a device used to fix the oil pipe inside the oil well casing, which can effectively prevent the oil pipe from moving and shrinking during the oil pumping process, reduce stroke loss, and improve oil pumping efficiency; the oil well casing anchor in the prior art is generally a hydraulic expansion anchor, that is, the anchor claw is pushed by hydraulic pressure to abut against the inner wall of the casing, and a huge friction force is generated therewith, thereby achieving the effect of fixing the anchor and the oil pipe, but the hydraulic pressure used for the movement of the internal structure of the anchor is limited, and the normal hydraulic oil pressure cannot be maintained during the long-term anchoring process. To solve this problem, the Chinese invention patent with patent number CN202210137668.5 discloses an oil well casing anchor. The anchor drives the rotating part to rotate through hydraulic oil, and cooperates with the screw and the slider to convert the rotary motion into linear motion that drives the rivet claw to move outward. The screw has a self-locking property to overcome the defect that the hydraulic oil pressure may weaken over a long period of time. However, its overall structure is complex, and not only does it require the addition of rotating parts and sealing parts, but it also causes losses during the pressure transmission process, which greatly reduces the transmission efficiency of hydraulic power. Moreover, due to the self-locking property of the screw, the entire anchor needs to be additionally designed with a reset structure when it is recovered, which makes the structure of the entire device more complicated and increases the potential risk of failure. Therefore, a simple and reliable anchor for oil well casing that amplifies hydraulic pressure is needed. Summary of the invention

[0003] The present application proposes an anchor for oil well casing, which has the advantages of high reliability, simple structure and high transmission efficiency, and is used to solve the problem of poor reliability caused by complex structure and complex transmission structure in the prior art.

[0004] To achieve the above purpose, the present application adopts the following technical solution: an anchor for oil well casing, comprising a mounting tube 1 and a mounting tube 2, wherein the interior of the mounting tube 1 is provided with an oil inlet chamber, a transmission chamber and a pressure chamber which are interconnected from top to bottom, and further comprising

[0005] A booster mechanism, the booster mechanism comprising a piston 1, a piston 2, a spring 1 and a connector, the piston 1 sealing sleeve is arranged on the inner wall of the transmission chamber, the piston 2 sealing sleeve is arranged on the inner wall of the booster chamber, the inner cavity between the piston 1 and the booster chamber and the inner cavity of the oil inlet chamber are filled with hydraulic oil, and the cross-sectional area of ​​the piston 1 is smaller than the cross-sectional area of ​​the piston 2;

[0006] The external support mechanism is provided with four groups and is equidistantly distributed along the bottom of the outer surface of the first mounting tube. The external support mechanism includes an active block fixedly connected to the bottom of the connector and a passive block slidably installed on the bottom of the outer surface of the first mounting tube. The active block and the passive block abut against each other and the abutting surface is smoothly inclined so that when the active block moves downward, the passive block can be horizontally pushed outward along the radial line of the first mounting tube. A spring groove is provided in the middle of the passive block, and a spring 2 is movably sleeved inside the spring groove.

[0007] The spring 1 is movably sleeved on the bottom of the inner wall of the boosting chamber, and the two ends of the spring 1 are elastically connected to the piston 2 and the bottom of the inner wall of the boosting chamber respectively.

[0008] Preferably, a placement groove is provided on the inner side surface of the active block, and a fixing column is fixedly installed on the inner wall of the placement groove, and a self-locking block and a spring four are movably sleeved on the outer surface of the fixing column, and two ends of the spring four are elastically connected to the self-locking block and one side of the inner wall of the placement groove respectively; an elastic reset component is provided on the inner side of the self-locking block, and the elastic reset component enables the self-locking block to maintain an abutment state with the outer surface of the mounting tube one; a self-locking groove located below the self-locking block is provided on the bottom of the outer surface of the mounting tube one, and the bottom of the self-locking block can be adapted to be snap-fitted with the self-locking groove; a limit block located directly below the self-locking groove is also fixedly installed on the outer surface of the mounting tube one, and a limit strip is fixedly connected to one side of the top of the limit block.

[0009] Preferably, the elastic reset assembly includes spring three and a self-locking column. A slot is provided at the bottom of the self-locking block close to the active block. The self-locking column is elastically supported in the slot by spring three. One end of the self-locking column facing the active block abuts against the inner side surface of the active block.

[0010] Preferably, the spring four is arranged on the side opposite to the limit strip, the top-view cross-section of the limit strip is a triangle, the hypotenuse of the limit strip faces the inclined side of the limit block, and the side of the limit strip away from the limit block is a straight side.

[0011] Preferably, the self-locking block is in an "L" shape, and the bottom of the self-locking block is in a right-angled trapezoid.

[0012] Preferably, the second spring passes through the four groups of spring slots, and the two ends of the second spring are not connected to the inner walls of the spring slots, and the second spring is spirally wound around the inner walls of the four groups of spring slots as a whole.

[0013] Preferably, four groups of slide grooves are provided at the bottom of the outer surface of the mounting tube 1, and the four groups of slide grooves are equidistantly distributed on the outer surface of the mounting tube 1 in a circle, and a connecting block is slidably installed on the inner wall of the slide groove, and the top of the connecting block is fixedly connected to the passive block.

[0014] Preferably, an outer side surface of the passive block is fixedly connected with an outer plate, and the outer side surface of the outer plate is arc-shaped.

[0015] Preferably, the axial cross-section of the connector is in a "T" shape, and the bottom end of the connector extends from the inner wall of the boost chamber to the bottom of an outer surface of the mounting tube.

[0016] Preferably, the top of the limit strip is higher than the self-locking groove, and the top of the limit strip is lower than the bottom of the self-locking block.

[0017] The beneficial effects of the present invention are as follows:

[0018] 1. This device has been optimized and uses Pascal's law to increase the anchoring external support hydraulic pressure. The overall design has high reliability. First, through the connection design of the transmission chamber and the boost chamber, the pressure on piston one is amplified several times by piston two. Then, the inclined surfaces between the active block and the passive block are abutted against each other to realize the external support anchoring function of the passive block and the external plate. Since the pressure of piston two is amplified several times through piston one, it is very easy for piston two to push the passive block downward through the connector and the active block to perform external support movement. The realization structure is mainly composed of several groups of interconnected sealed spaces: the oil inlet chamber, the transmission chamber and the boost chamber group. It has high reliability. Then, the large space inside the boost chamber is used to increase the downward movement stroke of piston 2 and the connector. Through the straight design of the outer side of the active block and the straight design of the inner side of the passive block, the connector drives the active block to move downward to the position where the inclined surface of the active block is out of sliding contact with the inclined surface of the passive block. The passive block no longer generates an upward reaction force on the active block. At this time, the pressure on piston 2 and piston 1 is reduced, and the power required for resetting piston 2, the connector and the active block is provided by spring 1. This design transfers most of the pressure of the reaction force of the passive block to the external oil pump, which can effectively extend the service life of the device.

[0019] 2. The device also realizes a self-locking function. A placement groove is provided on the inner side of the active block, and the self-locking block is installed by rotating inside the placement groove. The self-locking block uses the elastic reset component on its outer side to apply pressure so that the bottom of the self-locking block can always keep in contact with the outer surface of the installation tube. A self-locking groove is provided on the outer surface of the installation tube below the self-locking block, and the self-locking groove is automatically inserted into the self-locking groove under the action of the elastic reset component. At this time, the active block realizes a self-locking function for the passive block. The self-locking block is inserted into the self-locking groove, which limits the upward movement of the active block and offsets all the upward thrust acting on the surface of the active block. Even if the external hydraulic pressure fails, the device can maintain the anchoring state. The self-locking function has a simple structure and is durable. The top of the limit bar is higher than the self-locking slot, so that the self-locking block moves to the highest point and then resets under the elastic force of the spring four, thereby realizing the self-locking reset function. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings, which constitute a part of the specification, illustrate the embodiments disclosed in the present application and, together with the description, serve to explain the principles disclosed in the present application in a clear and understandable manner.

[0021] The present disclosure may be more clearly understood from the following detailed description with reference to the accompanying drawings, in which:

[0022] Figure 1 It is a three-dimensional cutaway schematic diagram of the overall structure;

[0023] Figure 2 It is a schematic diagram of the front appearance of the overall structure;

[0024] Figure 3 It is a front cutaway schematic diagram of the overall structure;

[0025] Figure 4 for Figure 3 A magnified schematic diagram of the structure at center A;

[0026] Figure 5 for Figure 3 A magnified schematic diagram of the structure at B in the middle;

[0027] Figure 6 It is a top view cutaway diagram of the installation pipe 1 and the active block;

[0028] Figure 7 for Figure 6A magnified schematic diagram of the structure at C in the middle;

[0029] Figure 8 It is a three-dimensional display diagram of the local structure;

[0030] Fig. 9 It is a cutaway schematic diagram of the overall structure;

[0031] Fig.10 for Fig. 9 A magnified schematic diagram of the structure at position D in the middle.

[0032] Among them: 1. Installation tube one; 2. Installation tube two; 3. Oil inlet chamber; 4. Transmission chamber; 5. Pressurization chamber; 6. Piston one; 7. Piston two; 8. Spring one; 9. Connector; 10. Active block; 11. Placement groove; 12. Fixed column; 13. Self-locking block; 14. Slide groove; 15. Connecting block; 16. Passive block; 17. Spring groove; 18. Spring two; 19. External plate; 20. Limit block; 21. Limit strip; 22. Self-locking groove; 23. Card slot; 24. Spring three; 25. Self-locking column; 26. Spring four. DETAILED DESCRIPTION

[0033] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0034] See also Figure 1-10 This example discloses an anchor for oil well casing, including a mounting pipe 1 and a mounting pipe 2. The mounting pipe 1 has an oil inlet chamber 3, a transmission chamber 4 and a pressure chamber 5 which are interconnected from top to bottom.

[0035] The boosting mechanism includes a piston 1 6, a piston 2 7, a spring 1 8 and a connector 9. The sealing sleeve of the piston 1 6 is arranged on the inner wall of the transmission chamber 4, and the sealing sleeve of the piston 2 7 is arranged on the inner wall of the boosting chamber 5. The inner cavity between the piston 1 6 and the boosting chamber 5 and the inner cavity of the oil inlet chamber 3 are filled with hydraulic oil. The cross-sectional area of ​​the piston 1 6 is smaller than the cross-sectional area of ​​the piston 2 7.

[0036] The external support mechanism is provided with four groups and is equidistantly distributed along the bottom of the outer surface of the mounting tube 1. The external support mechanism includes an active block 10 fixedly connected to the bottom of the connector 9 and a passive block 16 slidably mounted on the bottom of the outer surface of the mounting tube 1. The active block 10 and the passive block 16 abut against each other and the abutting surface is smoothly inclined, so that when the active block 10 moves downward, the passive block 16 can be horizontally pushed outward along the radial line of the mounting tube 1. A spring groove 17 is provided in the middle of the passive block 16, and a spring 18 is movably sleeved inside the spring groove 17.

[0037] The spring 1 8 is movably sleeved on the bottom of the inner wall of the boost chamber 5, and the two ends of the spring 1 8 are elastically connected to the piston 2 7 and the bottom of the inner wall of the boost chamber 5 respectively;

[0038] This device has been optimized and uses Pascal's law to increase the anchoring external support hydraulic pressure. The overall design has high reliability. First, through the connection design of the transmission chamber 4 and the boost chamber 5, the pressure on the piston 6 is amplified several times through the piston 2 7. Then, the inclined surfaces between the active block 10 and the passive block 16 are abutted against each other to achieve the external support anchoring function of the passive block 16 and the external plate 19. Since the pressure of the piston 2 7 is amplified several times through the piston 1 6, it is very easy for the piston 2 7 to push the passive block 16 downward through the connector 9 and the active block 10 to perform the external support movement. The implementation structure is mainly composed of several groups of interconnected sealed spaces: the oil inlet chamber 3, the transmission chamber 4 and the boost chamber 5, and has high reliability.

[0039] Then, the large space inside the boost chamber 5 is used to increase the downward movement stroke of the piston 2 7 and the connector 9. Through the straight design of the outer side of the active block 10 and the straight design of the inner side of the passive block 16, the connector 9 drives the active block 10 to move downward to the position where the inclined surface of the active block 10 and the inclined surface of the passive block 16 are out of sliding contact. The passive block 16 no longer generates an upward reaction force on the active block 10. At this time, the pressure on the piston 2 7 and the piston 1 6 is reduced, and the power required for the reset of the piston 2 7, the connector 9 and the active block 10 is provided by the spring 1 8. This design transfers most of the pressure of the reaction force of the passive block 16 to the external oil pump, which can effectively extend the service life of the device.

[0040] Example 2, please refer to Figure 1-Figure 10 :

[0041] A placement groove 11 is provided on the inner side of the active block 10, and a fixing column 12 is fixedly installed on the inner wall of the placement groove 11. A self-locking block 13 and a spring four 26 are movably sleeved on the outer surface of the fixing column 12. The two ends of the spring four 26 are elastically connected to the self-locking block 13 and one side of the inner wall of the placement groove 11 respectively. An elastic reset component is provided on the inner side of the self-locking block 13, and the elastic reset component enables the self-locking block 13 to maintain an abutment state with the outer surface of the mounting tube 1. A self-locking groove 22 located below the self-locking block 13 is provided at the bottom of the outer surface of the mounting tube 1. The bottom of the self-locking block 13 can be adapted and snap-fitted with the self-locking groove 22. A limit block 20 located directly below the self-locking groove 22 is also fixedly installed on the outer surface of the mounting tube 1, and a limit strip 21 is fixedly connected to one side of the top of the limit block 20.

[0042] The device also realizes a self-locking function, by opening a placement groove 11 on the inner side of the active block 10, and rotatably installing the self-locking block 13 inside the placement groove 11, the self-locking block 13 uses the elastic reset component on its outer side to apply pressure, so that the bottom of the self-locking block 13 can always keep in contact with the outer surface of the mounting tube 1, and by opening a self-locking groove 22 located below the self-locking block 13 on the outer surface of the mounting tube 1, and automatically snapping into the self-locking groove 22 under the action of the elastic reset component, the active block 10 realizes a self-locking function for the passive block 16 at this time, the self-locking block 13 is snapped into the self-locking groove 22, restricting the upward movement of the active block 10 and offsetting all upward thrusts acting on the surface of the active block 10, even if the external hydraulic pressure fails, the device can maintain the anchoring state, the self-locking function has a simple structure, is durable, and is fully capable of To achieve mass production or quick replacement, a limit block 20 is provided below the self-locking groove 22, and the top inclined surface of the limit block 20 pushes the self-locking block 13 moving downward toward the side close to the limit strip 21. At this time, the self-locking block 13 can move along the axis of the fixed column 12 and stretch the spring four 26. The self-locking block 13 passes over the limit strip 21 under the guidance of the limit block 20 and moves to the other side of the limit strip 21. At this time, the active block 10 drives the self-locking block 13 to move upward and reset, thereby utilizing the straight edge design on the other side of the limit strip 21 to prevent the self-locking block 13 from being re-stuck in the self-locking groove 22 during the upward movement. The top of the limit strip 21 is higher than the self-locking groove 22, so that the self-locking block 13 moves to the highest point and then resets under the elastic force of the spring four 26, thereby realizing the self-locking reset function.

[0043] Example 3, please refer to Figure 3-Figure 4 :

[0044] The elastic reset assembly includes a spring three 24 and a self-locking column 25. A slot 23 is provided at the bottom of the self-locking block 13 near the active block 10. The self-locking column 25 is elastically supported in the slot 23 by the spring three 24. One end of the self-locking column 25 facing the active block 10 abuts against the inner side surface of the active block 10.

[0045] The elastic reset component is located inside the card slot 23, and the spring three 24 applies elastic force to the self-locking column 25 outward, so that the outer end of the self-locking column 25 is always in contact with the inner side surface of the active block 10, thereby pushing the self-locking block 13 back to the outer surface of the mounting tube 1. As long as the self-locking block 13 enters the interior of the self-locking groove 22, it can be firmly stuck in the self-locking groove 22 under the elastic force of the spring three 24, thereby realizing the self-locking function of the device.

[0046] Example 4, please refer to Figure 5-Figure 8 , Fig.10 :

[0047] The spring 26 is arranged on the opposite side of the limit strip 21. The top view cross-section of the limit strip 21 is a triangle. The hypotenuse of the limit strip 21 faces the inclined side of the limit block 20, and the side of the limit strip 21 away from the limit block 20 is a straight side.

[0048] The spring four 26 is responsible for elastically connecting with the self-locking block 13 and keeping it in the middle position, ensuring that the self-locking block 13 can be stuck in the self-locking groove 22 downward. When the self-locking block 13 is limited and pushed to a position horizontally intersecting with the self-locking groove 22 by the limit block 20 and the limit strip 21, the spring four 26 is stretched until the self-locking block 13 moves upward to reset and automatically resets when it is free from the limit of the limit strip 21.

[0049] Example 5, please refer to Figure 1-Figure 3 :

[0050] The self-locking block 13 is in an "L" shape, and the bottom of the self-locking block 13 is in a right-angled trapezoid shape;

[0051] The “L”-shaped self-locking block 13 can always maintain contact with the outer surface of the mounting tube 1 under the action of the elastic reset component, thereby ensuring that the bottom of the self-locking block 13 can be smoothly inserted into the self-locking groove 22.

[0052] Example 6, please refer to Figure 1-Figure 3 , Figure 8-Figure 9 :

[0053] The second spring 18 runs through the four groups of spring slots 17, and the two ends of the second spring 18 are not connected to the inner wall of the spring slot 17. The second spring 18 is spirally wound around the inner wall of the four groups of spring slots 17 as a whole.

[0054] The four groups of passive blocks 16 are all provided with spring grooves 17, and spring 2 18 is spirally wound therein, so that the four groups of passive blocks 16 can be reset synchronously under the sliding cooperation of the connecting block 15. When the passive block 16 moves outward, the spring 2 18 is pulled to expand and generate tension, thereby ensuring that the passive block 16 can be automatically reset. This design reduces the number of spring 2 18, and the number of deployed spring 2 18 is reduced from four groups to one group.

[0055] Example 7, please refer to Figure 1-Figure 2 , Figure 8 :

[0056] Four groups of slide grooves 14 are provided at the bottom of the outer surface of the installation tube 1. The four groups of slide grooves 14 are equidistantly distributed on the outer surface of the installation tube 1 in a circumferential manner. A connecting block 15 is slidably installed on the inner wall of the slide groove 14. The top of the connecting block 15 is fixedly connected to the passive block 16.

[0057] The slide groove 14 is used for slidingly installing the connecting block 15 , and is fixedly connected to the passive block 16 through the connecting block 15 , so that the passive block 16 can expand outward horizontally and orderly along the axis of the slide groove 14 when being pressed downward by the active block 10 .

[0058] Example 8, please refer to Figure 1-Figure 3 , Figure 6 :

[0059] The outer side surface of the passive block 16 is fixedly connected with an outer plate 19, and the outer side surface of the outer plate 19 is in an arc shape;

[0060] The outer side surface of the outer plate 19 is in an arc shape, and can fit tightly with the inner wall of the oil well casing, thereby increasing the contact area.

[0061] Example 9, please refer to Figure 3 :

[0062] The axial cross-section of the connector 9 is in a "T" shape, and the bottom end of the connector 9 extends from the inner wall of the boost chamber 5 to the bottom of the outer surface of the mounting tube 1;

[0063] The connector 9 is composed of four groups of columns and a group of annular ring plates located outside the mounting tube 1. It receives the downward pressure from the piston 2 7 and drives the active block 10 to move downward, pressing the passive block 16 downward.

[0064] Example 10, please refer to Figure 2-Figure 5 :

[0065] The top of the limit strip 21 is higher than the self-locking groove 22, and the top of the limit strip 21 is lower than the bottom of the self-locking block 13;

[0066] The limit strip 21 is higher than the self-locking groove 22. When the self-locking block 13 moves downward along the straight edge of the limit strip 21 to the highest point, it can be reset under the elastic force of the spring four 26. During this process, the limit strip 21 limits the self-locking block 13 to the side of the self-locking groove 22 to prevent the self-locking block 13 from getting stuck in the self-locking groove 22 during the upward movement.

[0067] Working principle:

[0068] When the device is working, the oil pump is connected to the oil inlet at the top of the inner wall of the oil inlet chamber 3, and hydraulic oil is pumped into the inner cavity of the oil inlet chamber 3 to generate pressure on the piston 1 6. After the hydraulic oil enters the inner wall of the transmission chamber 4, the piston 1 6 pushes the hydraulic oil inside the transmission chamber 4 downward and transmits the pressure to the piston 2 7. According to Pascal's law, the ratio of the pressure on the piston 1 6 to the pressure on the piston 2 7 is equal to the ratio of the cross-sectional areas between the two. Therefore, the pressure transmitted downward by the piston 2 7 is doubled, and the spring 1 8 is compressed at the same time.

[0069] Then, the connector 9 drives the active block 10 and the self-locking block 13 to move downward continuously. The active block 10 pushes the passive block 16 horizontally toward the radial line of the installation pipe 1 by slidingly abutting against the passive block 16. At this time, the four groups of passive blocks 16 begin to expand outward synchronously, and at the same time stretch the spring 2 18. When the active block 10 drives the self-locking block 13 to move to the position where the self-locking block 13 is engaged with the self-locking groove 22, the passive block 16 expands outside and abuts against the oil well casing to generate friction, fixing the device. At this time, the outer side surface of the active block 10 abuts against the inner side surface of the passive block 16, and the inclined surfaces of the two are out of contact. The horizontal displacement of the passive block 16 remains unchanged, and the oil inlet cavity 3 is engaged in the self-locking groove 22, and the self-locking function is realized.

[0070] When the device is retracted, the connector 9 and the active block 10 continue to move downward under the action of hydraulic pressure, and drive the self-locking block 13 downward to break away from the inside of the self-locking groove 22, and then abut against the inclined surface of the limit block 20, and push the self-locking block 13 to the side close to the limit bar 21 through the limit block 20, so that the self-locking block 13 moves along the axis of the fixed column 12, stretching the spring 26. When the bottom of the self-locking block 13 contacts the limit bar 21, the self-locking block 13 passes over the inclined surface of the limit bar 21 and moves to the other side of the limit bar 21 to align with the installation pipe. 1, and the other side of the limit strip 21 is designed to be straight, so that the self-locking block 13 is limited, and the external oil pump absorbs the hydraulic oil in the oil chamber 3, so that the pressure on the piston 1 6 and the piston 2 7 is reduced. At the same time, the spring 1 8 is compressed to generate an upward rebound force, and begins to drive the piston 2 7, the connector 9, and the active block 10 to reset upward. At this time, after the self-locking block 13 is driven to move upward and reset, it begins to be higher than the limit strip 21 and resets under the action of the spring four 26, and the passive block 16 resets under the tension of the spring two 18.

[0071] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. An anchor for oil well casing, comprising a mounting tube 1 (1) and a mounting tube 2 (2), wherein the interior of the mounting tube 1 (1) is provided with an oil inlet chamber (3), a transmission chamber (4) and a pressure chamber (5) which are interconnected from top to bottom, characterized in that: Also includes A boosting mechanism, the boosting mechanism comprising a piston 1 (6), a piston 2 (7), a spring 1 (8) and a connector (9), the piston 1 (6) sealing sleeve being arranged on the inner wall of the transmission chamber (4), the piston 2 (7) sealing sleeve being arranged on the inner wall of the boosting chamber (5), the inner cavity between the piston 1 (6) and the boosting chamber (5) and the oil inlet chamber (3) being filled with hydraulic oil, and the cross-sectional area of ​​the piston 1 (6) being smaller than the cross-sectional area of ​​the piston 2 (7); An external support mechanism, which is provided with four groups and is equidistantly distributed along the bottom of the outer surface of the mounting tube (1), the external support mechanism comprising an active block (10) fixedly connected to the bottom of the connector (9) and a passive block (16) slidably installed on the bottom of the outer surface of the mounting tube (1), the active block (10) and the passive block (16) abutting against each other and the abutting surface is smoothly inclined, so that when the active block (10) moves downward, the passive block (16) can be horizontally pushed outward along the radial line of the mounting tube (1), a spring groove (17) is provided in the middle of the passive block (16), and a spring (18) is movably sleeved inside the spring groove (17); The spring one (8) is movably sleeved on the bottom of the inner wall of the boost chamber (5), and the two ends of the spring one (8) are elastically connected to the piston two (7) and the bottom of the inner wall of the boost chamber (5) respectively.

2. An oil well casing anchor according to claim 1, characterized in that: The inner side surface of the active block (10) is provided with a placement groove (11), the inner wall of the placement groove (11) is fixedly mounted with a fixing column (12), the outer surface of the fixing column (12) is movably sleeved with a self-locking block (13) and a spring four (26), the two ends of the spring four (26) are elastically connected to the self-locking block (13) and one side of the inner wall of the placement groove (11), and the inner side of the self-locking block (13) is provided with an elastic reset component, which enables the self-locking block (13) can maintain an abutment state with the outer surface of the mounting tube (1), the bottom of the outer surface of the mounting tube (1) is provided with a self-locking groove (22) located below the self-locking block (13), the bottom of the self-locking block (13) can be adapted to snap into the self-locking groove (22), and the outer surface of the mounting tube (1) is also fixedly provided with a limit block (20) located directly below the self-locking groove (22), and one side of the top of the limit block (20) is fixedly connected to the limit strip (21).

3. An anchor for oil well casing according to claim 2, characterized in that: The elastic reset assembly comprises a spring three (24) and a self-locking column (25); a bottom portion of the self-locking block (13) close to the active block (10) is provided with a slot (23); the self-locking column (25) is elastically supported in the slot (23) by the spring three (24); and one end of the self-locking column (25) facing the active block (10) abuts against the inner side surface of the active block (10).

4. An oil well casing anchor according to claim 3, characterized in that: The spring four (26) is arranged on the side opposite to the limit strip (21); the top-view cross-sectional shape of the limit strip (21) is a triangle; the hypotenuse of the limit strip (21) faces the inclined surface of the limit block (20); and the side of the limit strip (21) away from the limit block (20) is a straight side.

5. An oil well casing anchor according to claim 4, characterized in that: The self-locking block (13) is in an "L" shape, and the bottom of the self-locking block (13) is in a right-angled trapezoidal shape.

6. An oil well casing anchor according to claim 5, characterized in that: The second spring (18) passes through the four groups of spring slots (17), and the two ends of the second spring (18) are not connected to the inner walls of the spring slots (17). The second spring (18) is spirally wound around the inner walls of the four groups of spring slots (17).

7. An oil well casing anchor according to claim 6, characterized in that: Four groups of slide grooves (14) are provided at the bottom of the outer surface of the installation tube (1), and the four groups of slide grooves (14) are equidistantly distributed on the outer surface of the installation tube (1) in a circular shape. A connecting block (15) is slidably installed on the inner wall of the slide groove (14), and the top of the connecting block (15) is fixedly connected to the passive block (16).

8. An oil well casing anchor according to claim 7, characterized in that: The outer side surface of the passive block (16) is fixedly connected to an outer plate (19), and the outer side surface of the outer plate (19) is in an arc shape.

9. An oil well casing anchor according to claim 8, characterized in that: The axial cross-section of the connector (9) is in a "T" shape, and the bottom end of the connector (9) extends from the inner wall of the boost chamber (5) to the bottom of the outer surface of the mounting tube (1).

10. An oil well casing anchor according to claim 9, characterized in that: The top of the limiting strip (21) is higher than the self-locking groove (22), and the top of the limiting strip (21) is lower than the bottom of the self-locking block (13).

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