Dual oil drainage anchor and using method thereof

Abstract

The invention discloses a double oil drainage anchor and a using method thereof. The double oil drainage anchor comprises a central pipe, and the central pipe is sleeved with an anchor tile oil drainage mechanism; the upper end of the anchor tile oil drainage mechanism is further connected with an auxiliary oil drainage device. The auxiliary oil drainage device comprises a rotary oil drainage short section and a hydraulic oil drainage sliding sleeve; the anchor tile oil drainage mechanism comprises a slip mechanism and an anchor seal driving mechanism. Two oil drainage modes are provided, and the problems that oil drainage cannot be achieved due to anchor tile abrasion and scale blockage caused by conventional single-action oil drainage are solved. The application position method of the oil drainage anchor is provided, and a foundation is provided for long-term work of the oil drainage anchor.

Description

Technical Field

[0001] The invention relates to the technical field of oil drain anchors, in particular to a double oil drain anchor and a use method thereof. Background Art

[0002] The lifting pipe string of the pumping well mostly uses tools such as pin oil drainers and oil drain anchors to drain oil in the later stage of operation. When the plunger valve cover of the pipe string using the pin oil drainer breaks, the plunger in the pump barrel cannot be salvaged and the pipe string cannot drain oil; some oil wells use rotating oil drain anchors, but when the sand and iron filings in the well bury the pump barrel, it is also impossible to drain oil, or when the lifting pipe string vibrates for a long time, the slips of the oil drain anchor and the casing wear and fail, and cannot provide sufficient friction in the later stage, and cannot drain oil, etc. In the scaling well, the slips of the oil drain anchor will also be scaled and cannot effectively drain oil.

[0003] Publication (Announcement) No.: CN114151040B, discloses an oil pipe drainer, relates to the technical field of oil drainers, comprises a casing, an oil pipe is arranged inside the casing, an oil drain port is opened on the surface of the oil pipe, an oil drainer is arranged outside the oil drain port on the outer sleeve of the oil pipe, the oil drainer comprises a sealing tube sleeved outside the oil drain port, a driving tube is arranged on one side of the sealing tube on the outer sleeve of the oil pipe, an annular driving chamber is opened inside the driving tube, an annular driving piston is slidably connected inside the annular driving chamber, a connecting ring is fixedly connected to the side wall of the annular driving piston, the end of the connecting ring passes through the driving pipe and is sealed and slidably connected thereto, the end of the connecting ring is rotatably connected to the side wall of the sealing pipe, a first spring is elastically connected between the annular driving piston and the annular driving chamber, a limiting channel is opened on the side wall of the driving pipe, and a first limiting component for limiting the position of the annular driving piston is arranged in the limiting channel. The invention solves the problem of how to quickly and stably drain the oil in the oil pipe.

[0004] The anchoring method of the prior art is hydraulic anchoring, but due to its structural reasons, when the tubing anchor is lowered into the tubing string, friction occurs between the tubing anchor and the inner wall of the casing or collision occurs between the tubing anchor and the casing coupling, causing the slips of the anchor to wear and fall off, resulting in ineffective sealing and failure to drain oil later.

[0005] Publication (announcement) number: CN207701111U, discloses an anchoring oil drain device for an oil pump, comprising a center tube, an upper joint and a lower joint, characterized in that: the external thread at the lower end of the upper joint is screwed into the internal thread of the upper cone, an outer core tube is installed at the lower part of the upper cone, the outer core tube is threadedly connected to the rubber cylinder seat, a seating locking anchoring mechanism is sleeved on the outer ring space of the outer core tube, the upper end of the sealing cylinder is threadedly connected to the rubber cylinder seat, and the lower end is threadedly connected to the seating sealing sleeve, a locking ring is installed in the annulus between the sealing cylinder and the lower joint, when performing anchoring operation, the seating sealing sleeve is locked into the locking ring, and the lower end of the locking ring is supported by a support body, the unsealing shear pins arranged in the support body are embedded in the shear pin groove of the lower joint for fixing, and the seating shear pins arranged in the seating sealing sleeve are embedded in the shear groove of the support body for control and fixing. The utility model adopts a seat-card locking anchoring mechanism to make the anchoring of the oil pump pipe string more reliable. When the pump is inspected, the pipe string can be lifted up to discharge oil into the wellbore by itself, thereby realizing civilized and safe oil well operation and preventing environmental pollution.

[0006] The anchoring method of the prior art is hydraulic anchoring, but due to its structural reasons, when the tubing anchor is lowered into the tubing string, friction occurs between the tubing anchor and the inner wall of the casing or collision occurs between the tubing anchor and the casing coupling, causing the slips of the anchor to wear and fall off, resulting in ineffective sealing and failure to drain oil later.

[0007] Publication (Announcement) No.: CN210918945U discloses a pump anchor. The utility model has the following characteristics: internal pressure hydraulic sitting and hanging, lifting the pipe string to unhang, while lifting and unhanging, the slip seat slides down, opens the oil drain hole, lifts the pipe string to drain the liquid in the pipe string, and no oil drainer is installed; the on-site adjustment of the unhanging force is achieved by increasing or decreasing the number of unhanging pins; when the tool of the utility model is lowered into the well, the grouting sleeve is automatically opened by the pressure difference, the pressure inside and outside the pipe is kept balanced, and automatic grouting is achieved. The slip seat has a guide key, and the guide also ensures that the slip cannot rotate. The slip has a two-way anchoring function and the anchoring is reliable. There is a locking mechanism, and once anchored, it cannot be loosened. The slip is a wedge-shaped structure, and pressing down or pulling down will make the anchor tighter. The slip opens synchronously to ensure that the sitting and hanging are centered. There is a shear safety joint. When unhanging, once the unhanging force exceeds the shear force of the safety joint, the safety joint is disconnected to ensure that the upper part of the anchor is lifted out of the pipe, and the lower part of the anchor is fished out by other means.

[0008] The anchoring method of the prior art is hydraulic anchoring, but due to its structural reasons, when the tubing anchor is lowered into the tubing string, friction occurs between the tubing anchor and the inner wall of the casing or collision occurs between the tubing anchor and the casing coupling, causing the slips of the anchor to wear and fall off, resulting in ineffective sealing and failure to drain oil later.

[0009] In summary, the technical solutions of the above-disclosed technologies, the technical problems to be solved, and the beneficial effects produced are all different from the present invention. Regarding more technical features, technical problems to be solved, and beneficial effects of the present invention, the above-disclosed technical documents do not provide any technical inspiration. Summary of the invention

[0010] In view of the above-mentioned defects in the prior art, the purpose of the present invention is to provide a double oil drainage anchor and a method of using the same, providing two oil drainage methods to solve the problems of anchor shoe wear and oil drainage failure caused by conventional single-action oil drainage, and scale stuck and oil drainage failure.

[0011] In order to achieve the above object, the present invention adopts the following technical solutions:

[0012] A double oil-draining anchor and a method of using the same, comprising a central tube, on which an anchor shoe oil-draining mechanism is sleeved;

[0013] The upper end of the anchor shoe oil leakage mechanism is also connected to an auxiliary oil leakage device.

[0014] The auxiliary oil drain device includes a rotary oil drain nipple and a hydraulic oil drain sleeve;

[0015] The lower end of the rotary oil leakage short section is connected to the anchor shoe oil leakage mechanism, and the rotary oil leakage short section is provided with a first pressure transmission hole and a first oil leakage hole;

[0016] The hydraulic oil drain sleeve is sleeved on the outside of the rotary oil drain nipple and can block the first oil drain hole;

[0017] The inner wall of the hydraulic oil drain sleeve is provided with a pressure-bearing step surface corresponding to the first pressure transmission hole;

[0018] The hydraulic oil drain sliding sleeve is fixed in position by controlling the shear pins and the rotary oil drain short joint.

[0019] At least two control shear pins are provided.

[0020] The anchor shoe oil leakage mechanism includes a slip mechanism and an anchor seal driving mechanism;

[0021] The anchor seal driving mechanism is sleeved on the central pipe;

[0022] The slip mechanism is connected to the upper end of the central tube.

[0023] The slip mechanism comprises a cone and an anchor shoe;

[0024] The lower end of the cone is connected to the upper end of the central tube, and the rotary oil drain nipple is sleeved in the cone;

[0025] The rotary oil-draining nipple is provided with a second oil-draining hole at the cone portion; and the cone is provided with an anchor shoe oil-draining channel corresponding to the second oil-draining hole.

[0026] The upper end of the anchor shoe is provided with an inner conical surface, the lower end of the cone is provided with an outer conical surface, and the inner conical surface is in contact with the outer conical surface.

[0027] The anchor seal driving mechanism includes a piston sleeve, a fixed sleeve, and an automatic reset mechanism;

[0028] The piston sleeve is sleeved on the central tube, and the upper end of the piston sleeve is in contact with the lower end of the anchor shoe;

[0029] The fixed sleeve is sleeved on the outer wall of the central tube, and the fixed sleeve is located inside the piston sleeve, and the inner wall of the piston sleeve is slidably sealed with the outer wall of the fixed sleeve and the outer wall of the central tube at the same time;

[0030] The piston sleeve is connected to the fixed sleeve inside the piston sleeve through pressure test shear pins;

[0031] The central tube is provided with a second pressure transmission hole, and the space above the fixed sleeve in the piston sliding sleeve of the second pressure transmission hole is communicated with the central tube.

[0032] The automatic reset mechanism includes a spring and a pressing cap;

[0033] The outer wall of the pressing cap is fixedly connected to the lower end of the piston sliding sleeve, the inner wall of the pressing cap is slidably connected to the outer wall of the central tube, the upper end of the spring supports the lower end of the fixing sleeve, and the lower end of the spring supports the upper end of the pressing cap.

[0034] The outer wall of the piston sleeve extends upwards out of a pressure plate.

[0035] A dovetail groove matching with the cone is arranged on the outer periphery of the upper end of the central tube; the cone is connected with the central tube through the dovetail groove.

[0036] The inner wall of the hydraulic oil drain sleeve and the outer wall of the rotary oil drain nipple are sliding seals;

[0037] An upper pressure cap is provided at the upper end of the cone, and a sealing ring is provided inside the upper pressure cap;

[0038] The upper end of the auxiliary oil drain device is connected to the upper joint.

[0039] In order to achieve the above object, the present invention adopts the following technical solutions:

[0040] A method for using a double oil spill anchor.

[0041] S1: Preparation work, installing a double oil drain anchor 3 on the oil pipe 2, and lowering it into the well after installing other equipment;

[0042] S2: Anchoring in the well. The rod column carrying the plunger is lowered into the tubing. The plunger collides with the shear pins of the oil drain anchor, and the first and second pressure transmission holes are opened. The piston sleeve pushes the anchor shoe to move outward along the cone and anchor to the inner wall of the casing under the pressure difference between the pressure in the tubing and the pressure in the casing annulus.

[0043] S3: Unblock and drain oil. According to the anchor position and wellbore structure, the pipe string is lifted up a certain distance to make the oil drain anchor bear a tensile load of 200-500kg. Then the pipe string is rotated a certain number of times to cut off the control shear pins and drain oil.

[0044] S4: Auxiliary oil leakage. When the unblocking and oil leakage fails, auxiliary oil leakage is carried out. Pressure is applied to the oil pipe to break the control shear pins, so that the first oil leakage hole is exposed and oil leakage begins.

[0045] The specific position of the dual oil drain anchor on the oil pipe is calculated according to the following formula:

[0046]

[0047] h: distance from the top of the oil pump, m;

[0048] n: stroke times, min -1 ;

[0049] α: well inclination angle at the location of the drain anchor, degrees;

[0050] f w : moisture content, %;

[0051] m l :Ca 2+ Mg 2+ The sum of ions, mg / L.

[0052] Compared with the prior art, the present invention has the following beneficial effects:

[0053] 1. Two oil drainage methods are provided to solve the problems of anchor shoe wear and oil drainage failure caused by conventional single-effect oil drainage, and scale stuck and oil drainage failure.

[0054] 2. Provides a method for the application location of the oil spill anchor, laying a foundation for the long-term operation of the oil spill anchor.

[0055] In summary, the present invention can use the rotary oil leakage method to perform internal oil leakage in the oil pipe, and can also use the pressurization and sliding shearing methods to perform secondary oil leakage after the rotary oil leakage action fails. The use of two oil leakage methods makes the oil leakage effect more reliable, and the operation is simple and convenient, and the practicability is strong. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Figure 1 It is a structural schematic diagram of a double oil drain anchor of the present invention;

[0057] Figure 2 It is a structural schematic diagram of a first embodiment of a double oil spill anchor of the present invention;

[0058] Figure 3 It is a structural schematic diagram of a second embodiment of a double oil spill anchor of the present invention;

[0059] Figure 4 It is a structural schematic diagram of a third embodiment of a double oil drain anchor of the present invention;

[0060] In the figure: 1. sucker rod; 2. oil pipe; 3. a double oil leakage anchor; 4. oil pump; 5. screen pipe; 6. thread plug; 7. sand settling device; 8. disconnector; 31. upper joint; 32. rotary oil leakage short joint; 33. first pressure transmission hole; 34. first oil leakage hole; 35. hydraulic oil leakage sliding sleeve; 36. control shear pin; 37. upper pressure cap; 38. cone; 39. anchor shoe; 310. center pipe; 311. piston sliding sleeve; 312. second pressure transmission hole; 313. spring; 314. lower pressure cap; 315. second oil leakage hole. DETAILED DESCRIPTION

[0061] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0062] See also Figure 1 The present invention provides a double oil-draining anchor and a method for using the same, comprising a central tube 310, on which an anchor shoe oil-draining mechanism is sleeved; an auxiliary oil-draining device is also connected to the upper end of the anchor shoe oil-draining mechanism.

[0063] The auxiliary oil drain device includes a rotary oil drain nipple 32 and a hydraulic oil drain sleeve 35;

[0064] The lower end of the rotary oil leakage short section 32 is connected to the anchor shoe oil leakage mechanism, and the rotary oil leakage short section 32 is provided with a first pressure transmission hole 33 and a first oil leakage hole 34;

[0065] The hydraulic oil leakage sleeve 35 is sleeved on the outside of the rotary oil leakage short section 32, and can block the first oil leakage hole 34. At the same time, the inner wall of the hydraulic oil leakage sleeve 35 is provided with a pressure step surface corresponding to the first pressure transmission hole 33. The hydraulic pressure passes through the first pressure transmission hole 33 to generate pressure on the pressure step surface, so that the hydraulic oil leakage sleeve 35 moves axially downward, thereby releasing the first oil leakage hole 34.

[0066] The hydraulic oil drain sleeve 35 is fixedly positioned with the rotary oil drain nipple 32 by means of a control shear pin 36 , and the control shear pin 36 can prevent the first oil drain hole 34 from accidentally opening.

[0067] At least two control shear pins 36 are provided. By providing different numbers of control shear pins 36, it is convenient to adjust the pressure during oil leakage.

[0068] The inner wall of the hydraulic oil drain sleeve 35 and the outer wall of the rotary oil drain nipple 32 form a sliding seal.

[0069] The anchor shoe oil leakage mechanism includes a slip mechanism and an anchor seal driving mechanism;

[0070] The anchor seal driving mechanism is sleeved on the central tube 310, the slip mechanism is connected to the upper end of the central tube 310, and the auxiliary oil leakage device is sleeved in the slip mechanism.

[0071] The slip mechanism includes a cone 38 and an anchor shoe 39; the lower end of the cone 38 is connected to the upper end of the center tube 310, the rotary oil drain nipple 32 is sleeved in the cone 38, and the rotary oil drain nipple 32 is provided with a second oil drain hole 315 at the portion connected to the cone 38; the cone 38 is provided with an anchor shoe oil drain channel corresponding to the second oil drain hole 315;

[0072] The anchor shoe 39 is mounted on the center tube 310; an inner conical surface is arranged at the upper end of the anchor shoe 39, and an outer conical surface is arranged at the lower end of the cone 38. The inner conical surface contacts the outer conical surface. When the anchor shoe 39 moves upward along the axial direction, it will be pushed out and stuck with the casing. At the same time, the anchor shoe 39 will block the anchor shoe oil leakage channel, and open the oil leakage when unsealed.

[0073] The anchor seal driving mechanism includes a piston sleeve 311, a fixed sleeve, and an automatic reset mechanism;

[0074] The piston sleeve 311 is sleeved on the central tube 310, the upper end of the piston sleeve 311 contacts the lower end of the anchor shoe 39, the fixed sleeve is sleeved on the outer wall of the central tube 310, and the fixed sleeve is located inside the piston sleeve 311, and the inner wall of the piston sleeve 311 is slidably sealed with the outer wall of the fixed sleeve and the outer wall of the central tube 310;

[0075] The piston sleeve 311 is connected to the fixed sleeve inside the piston sleeve through pressure test shear pins;

[0076] The central tube 310 is provided with a second pressure transmission hole 312, and the second pressure transmission hole 312 can be connected to the space above the fixed sleeve in the piston sleeve 311;

[0077] The automatic reset mechanism includes a spring 313 and a pressing cap 314; the outer wall of the pressing cap 314 is fixedly connected to the lower end of the piston sleeve 311, the inner wall of the pressing cap 314 is slidably connected to the outer wall of the center tube 310, the upper end of the spring 313 supports the lower end of the fixed sleeve, and the lower end of the spring supports the upper end of the pressing cap 314.

[0078] A pressure plate extends upward from the outer wall of the piston sleeve 311 to prevent the anchor shoe 39 from falling off;

[0079] The cone 38 has an upper pressure cap 37 at its upper end, and a sealing ring is provided inside the upper pressure cap 37 to ensure a sealed sliding connection between the upper pressure cap 37 and the rotary oil drain nipple 32.

[0080] The outer periphery of the upper end of the central tube 310 is provided with a dovetail groove matching with the cone 38; the cone 38 is connected to the central tube 310 through the dovetail groove;

[0081] The upper end of the auxiliary oil drain device is connected to the upper joint 31 .

[0082] Embodiment 1:

[0083] according to Figure 2 As shown, a pumping unit screen tube string includes an oil pipe 2, in which a sucker rod 1, an oil pump 4, a screen tube 5, and a screw plug 6 are arranged from top to bottom. A double oil drainage anchor 3 is also arranged on the oil pipe 2.

[0084] Embodiment 2:

[0085] according to Figure 3 As shown, a sand settling pipe string for an oil pump comprises an oil pipe 2, in which a sucker rod 1, an oil pump 4, a sand settling device 7, and a screw plug 6 are arranged in sequence from top to bottom. A double oil drain anchor 3 is also arranged on the oil pipe 2.

[0086] Embodiment 3:

[0087] according to Figure 4 As shown, a pumping unit with a detachable oil rod column comprises an oil pipe 2, in which a sucker rod 1, an oil pump 4, a disconnector 8, a screen 5, and a plug 6 are arranged from top to bottom, and a double oil drain anchor 3 is also arranged on the oil pipe 2.

[0088] In combination with all embodiments, the method of using the present invention is as follows:

[0089] S1: Preparation work, installing a double oil drain anchor 3 on the oil pipe 2, and lowering it into the well after installing other equipment;

[0090] S2: Anchoring in the well, the rod column carrying the plunger is lowered into the oil pipe 2, the plunger collides with the shear pins of the oil drain anchor, the first and second pressure transmission holes (33, 312) are opened, and the piston sleeve 311 pushes the anchor shoe 39 to move outward along the cone and anchor to the inner wall of the casing under the pressure difference between the pressure in the oil pipe 2 and the pressure in the casing annulus.

[0091] S3: Unblocking and draining oil. According to the anchoring position and wellbore structure, the pipe string is lifted up a certain distance, so that the drain anchor is subjected to a tensile load of 200-500 kg. Then the pipe string is rotated a certain number of times to cut off the control shear pin 36 and drain the oil.

[0092] S4: auxiliary oil leakage. When the unblocking and oil leakage fails, auxiliary oil leakage is performed by pressing the inside of the oil pipe 2 to break the control shear nail 36, so that the first oil leakage hole 34 is exposed and the oil leakage begins.

[0093] The specific position of the double oil drain anchor 3 on the oil pipe can be calculated according to the following formula in different well conditions to better meet the working needs:

[0094]

[0095] h: distance from the top of the oil pump, m;

[0096] n: stroke times, min -1 ;

[0097] α: well inclination angle at the location of the drain anchor, degrees;

[0098] f w : moisture content, %;

[0099] m l :Ca 2+ Mg 2+ The sum of ions, mg / L.

[0100] All components and connection methods of components not discussed in this application belong to the known technologies in this technical field and can be directly applied without further explanation.

[0101] In the present invention, the term "plurality" refers to two or more than two, unless otherwise clearly defined. The terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; "connected" can be a direct connection or an indirect connection 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 the specific circumstances.

[0102] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by terms such as “upper”, “lower”, “left”, “right”, “front” and “back” are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or unit referred to must have a specific direction, be constructed and operated in a specific orientation, and therefore, cannot be understood as a limitation on the present invention.

[0103] 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.

[0104] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A double oil drain anchor, comprising a central tube, characterized in that: The central tube is provided with an anchor shoe oil drain mechanism; The upper end of the anchor shoe oil leakage mechanism is also connected to an auxiliary oil leakage device.

2. A double oil drain anchor according to claim 1, characterized in that: The auxiliary oil drain device includes a rotary oil drain nipple and a hydraulic oil drain sleeve; The lower end of the rotary oil leakage short section is connected to the anchor shoe oil leakage mechanism, and the rotary oil leakage short section is provided with a first pressure transmission hole and a first oil leakage hole; The hydraulic oil drain sleeve is sleeved on the outside of the rotary oil drain nipple and can block the first oil drain hole; The inner wall of the hydraulic oil drain sleeve is provided with a pressure-bearing step surface corresponding to the first pressure transmission hole; The hydraulic oil drain sliding sleeve is fixed in position by controlling the shear pins and the rotary oil drain short joint.

3. A double oil drain anchor according to claim 2, characterized in that: The anchor shoe oil leakage mechanism includes a slip mechanism and an anchor seal driving mechanism; The anchor seal driving mechanism is sleeved on the central pipe; The slip mechanism is connected to the upper end of the central tube.

4. A double oil drain anchor according to claim 3, characterized in that: The slip mechanism comprises a cone and an anchor shoe; The lower end of the cone is connected to the upper end of the central tube, and the rotary oil drain nipple is sleeved in the cone; The rotary oil-draining nipple is provided with a second oil-draining hole at the cone portion; and the cone is provided with an anchor shoe oil-draining channel corresponding to the second oil-draining hole.

5. A double oil drain anchor according to claim 4, characterized in that: The upper end of the anchor shoe is provided with an inner conical surface, the lower end of the cone is provided with an outer conical surface, and the inner conical surface is in contact with the outer conical surface.

6. A dual oil drain anchor according to claim 5, characterized in that: The anchor seal driving mechanism includes a piston sleeve, a fixed sleeve, and an automatic reset mechanism; The piston sleeve is sleeved on the central tube, and the upper end of the piston sleeve is in contact with the lower end of the anchor shoe; The fixed sleeve is sleeved on the outer wall of the central tube, and the fixed sleeve is located inside the piston sleeve, and the inner wall of the piston sleeve is slidably sealed with the outer wall of the fixed sleeve and the outer wall of the central tube at the same time; The piston sleeve is connected to the fixed sleeve inside the piston sleeve through pressure test shear pins; The central tube is provided with a second pressure transmission hole, and the space above the fixed sleeve in the piston sliding sleeve of the second pressure transmission hole is communicated with the central tube.

7. A dual oil drain anchor according to claim 6, characterized in that: The automatic reset mechanism includes a spring and a pressing cap; The outer wall of the pressing cap is fixedly connected to the lower end of the piston sliding sleeve, the inner wall of the pressing cap is slidably connected to the outer wall of the central tube, the upper end of the spring supports the lower end of the fixing sleeve, and the lower end of the spring supports the upper end of the pressing cap.

8. A dual oil drain anchor according to claim 7, characterized in that: The outer wall of the piston sleeve extends upwards out of a pressure plate.

9. A dual oil drain anchor according to claim 8, characterized in that: A dovetail groove matching with the cone is arranged on the outer periphery of the upper end of the central tube; the cone is connected with the central tube through the dovetail groove.

10. A double oil drain anchor according to claim 9, characterized in that: The inner wall of the hydraulic oil drain sleeve and the outer wall of the rotary oil drain nipple are sliding seals; An upper pressure cap is provided at the upper end of the cone, and a sealing ring is provided inside the upper pressure cap; The upper end of the auxiliary oil drain device is connected to the upper joint.

11. A double oil drain anchor according to any one of claims 2 to 10, characterized in that: At least two control shear pins are provided.

12. A method for using a double oil spill anchor, characterized in that: S1: Preparation work, install a double oil drain anchor on the oil pipe, and lower it into the well after installing other equipment; S2: Anchoring downhole, lower the rod string carrying the plunger into the tubing, the plunger hits the shear pins of the oil drain anchor, the first and second pressure transmission holes are opened, and the piston sleeve pushes the anchor shoe to move outward along the cone and anchor to the inner wall of the casing under the pressure difference between the pressure in the tubing and the pressure in the casing annulus; S3: Unblock the oil and drain the oil. According to the anchor position and wellbore structure, lift the pipe string so that the oil drain anchor bears a tensile load of 200-500kg. Then rotate the pipe string forward to cut off the control shear pins and drain the oil. S4: Auxiliary oil leakage. When the unblocking and oil leakage fails, auxiliary oil leakage is carried out. Pressure is applied to the oil pipe to break the control shear pins, so that the first oil leakage hole is exposed and oil leakage begins.

13. A method for using a dual oil spill anchor according to claim 12, characterized in that: The specific position of the dual oil drain anchor on the oil pipe is calculated according to the following formula: h: distance from the top of the oil pump, m; n: stroke times, min -1 ; α: well inclination angle at the location of the drain anchor, degrees; f w : moisture content, %; m l :Ca 2+ Mg 2+ The sum of ions, mg / L.

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