Anti-blocking hydraulic anchor with forcibly recycled anchor teeth

Abstract

The invention relates to the technical field of hydraulic anchors, in particular to an anti-blocking hydraulic anchor with forcibly recycled anchor teeth, which comprises an anchor body, anchor teeth, a sand prevention pipe and a depression bar, three vertically through liquid passing grooves are arranged on the outer side of the anchor body along the circumference, a through fluid channel is arranged in the middle of the anchor body, and at least one anchor tooth group is arranged on the anchor body at intervals left and right. Each anchor tooth group comprises at least two anchor tooth holes which are formed along the circumference, anchor teeth are arranged in each anchor tooth hole, tooth tips of the anchor teeth face outwards, the inner side of the middle part of the fluid channel is in threaded connection with a sand prevention pipe, a slot is formed in the sand prevention pipe corresponding to each anchor tooth hole, a groove with an outward opening is formed in the outer end of each anchor tooth, and an elastic sheet is arranged in each groove; and a pressing strip capable of pressing the elastic sheet is fixedly arranged on the anchor body corresponding to the position of the groove. The device is reasonable and compact in structure and convenient to use, anchoring is carried out by arranging the anchor teeth, the anchor teeth can be assisted to be recycled by arranging the elastic pieces, and the effect that a drill is not prone to being stuck is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of hydraulic anchors, in particular to an anti-stuck hydraulic anchor with forcedly recovered anchor teeth. Background Art

[0002] During the downhole operations such as fracturing, water injection and testing in oil and gas fields, in order to prevent the axial creep of the pipe string under the piston effect and the internal and external pressure difference, the packer will be displaced up and down, the rubber tube will be worn, and the packer will be lost. In order to avoid the above situation, hydraulic anchors are generally added to the pipe string for anchoring. Under the action of the internal and external pressure difference, the anchor teeth of the hydraulic anchor extend out and anchor on the casing wall, fixing the pipe string axially to prevent the relative displacement of the working pipe string and tools and the casing, causing damage or failure of the tool. However, in the actual operation process, after the extension of some hydraulic anchor teeth, the anchor teeth are not smoothly returned because the anchor teeth are embedded in the inner wall of the casing, or because of the scaling of the tools and the inner wall of the casing, etc., the hydraulic anchor teeth cannot be recovered under the elastic force of the spring or shrapnel, and the pipe string and tools are stuck when drilling. If the jam is to be released, it is necessary to repeatedly move vigorously or reverse circulation pressure to force the jam, which increases the operation risk, affects the operation time, and increases the operation cost. Summary of the invention

[0003] The present invention provides an anti-stuck hydraulic anchor with forced recovery of anchor teeth, which overcomes the deficiencies of the above-mentioned prior art and can effectively solve the existing problems of time-consuming and labor-intensive construction, low construction efficiency and potential safety hazards.

[0004] The technical solution of the present invention is achieved through the following measures: an anti-stuck hydraulic anchor with forced recovery of anchor teeth, comprising an anchor body, anchor teeth, a sand control tube, and a pressure strip, wherein three liquid flow grooves penetrating up and down are arranged along the circumference of the outer side of the anchor body, a penetrating fluid channel is arranged in the middle of the anchor body, at least one group of anchor tooth groups are arranged on the left and right sides of the anchor body at intervals, each group of anchor tooth groups comprises at least two anchor tooth holes arranged along the circumference, each anchor tooth is arranged in each anchor tooth hole, the anchor tooth tip faces outward, a sand control tube is threadedly connected to the inner side of the middle of the fluid channel, a slit is arranged on the sand control tube corresponding to the position of each anchor tooth hole, a groove opening outward is arranged at the outer end of each anchor tooth, a spring sheet is arranged in the groove, and a pressure strip capable of pressing the spring sheet is fixedly installed on the anchor body corresponding to the position of the groove.

[0005] The following are further optimizations and / or improvements to the above technical solutions: The above-mentioned anchor tooth may include a first straight section and a second straight section that are integrally arranged, the outer diameter of the first straight section is larger than that of the second straight section, the first straight section is located at the outer end, and installation grooves are provided on the outer sides of the first straight section and the second straight section, and a first sealing ring and a second sealing ring are respectively installed in each installation groove, and the size of the first sealing ring is larger than that of the second sealing ring.

[0006] The anchor body corresponding to the outer position of each anchor tooth may be provided with a buffer cavity that penetrates inside and outside, and a plug is installed at the open end of the buffer cavity. The anchor body corresponding to the position between the first sealing ring and the second sealing ring is provided with a pressure-conducting hole connected to the adjacent buffer cavity.

[0007] The anchor body may be provided with two groups of anchor teeth at intervals on the left and right sides, and each group of anchor teeth includes three anchor teeth holes evenly distributed along the circumference.

[0008] The surface of the anchor tooth tip can be nitrided.

[0009] The invention has a reasonable and compact structure and is easy to use. It is anchored by arranging anchor teeth, and can assist the anchor teeth in recovery by arranging spring pieces, so that the drill is not easily stuck. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Attached Figure 1 It is a schematic diagram of the front cross-sectional structure of an embodiment of the present invention.

[0011] Attached Figure 2 For attachment Figure 1 Schematic diagram of the cross-sectional structure at AA.

[0012] Attached Figure 3 For attachment Figure 1 Schematic diagram of the main structure of the middle anchor tooth.

[0013] Attached Figure 4 For attachment Figure 3 Schematic diagram of the structure of the middle anchor tooth from above.

[0014] The codes in the accompanying drawings are: 1 is the anchor body, 2 is the anchor tooth, 3 is the sand control pipe, 4 is the pressure strip, 5 is the liquid flow groove, 6 is the spring piece, 7 is the first sealing ring, 8 is the second sealing ring, 9 is the buffer cavity, 10 is the pressure guide hole, 11 is the installation groove, 12 is the plug, 13 is the groove, 14 is the first straight section, and 15 is the second straight section. DETAILED DESCRIPTION

[0015] The present invention is not limited by the following embodiments, and specific implementation methods can be determined based on the technical solution of the present invention and actual conditions.

[0016] In the present invention, for the convenience of description, the relative position relationship of each component is described according to the attached Figure 1 The positional relationships such as front, back, top, bottom, left, and right are described according to the layout directions of the drawings in the specification.

[0017] The present invention will be further described below in conjunction with embodiments and drawings: Embodiment 1: As attached Figure 1 , 2As shown in Figures 3 and 4, the anti-stuck hydraulic anchor for forced recovery of anchor teeth comprises an anchor body 1, anchor teeth 2, a sand control tube 3 and a pressure strip 4. Three liquid flow grooves 5 penetrating from top to bottom are provided along the circumference of the outer side of the anchor body 1, a penetrating fluid channel is provided in the middle of the anchor body 1, at least one group of anchor tooth groups are provided on the anchor body 1 at intervals on the left and right, each group of anchor tooth groups comprises at least two anchor tooth holes arranged along the circumference, an anchor tooth 2 is provided in each anchor tooth hole, the tooth tip of the anchor tooth 2 faces outward, a sand control tube 3 is threadedly connected to the inner side of the middle of the fluid channel, a slit is provided on the sand control tube 3 corresponding to the position of each anchor tooth hole, a groove 13 opening outward is provided at the outer end of each anchor tooth 2, a spring sheet 6 is provided in the groove 13, and a pressure strip 4 capable of pressing the spring sheet 6 is fixedly installed on the anchor body 1 corresponding to the position of the groove 13.

[0018] When the oil pressure is greater than the casing pressure, the pressure difference between the inside and outside of the anchor body 1 flows into the anchor hole through the slit of the sand control tube 3 to push out the anchor 2. When the anchor 2 outside the groove 13 extends outward, it squeezes the spring piece 6 to store elastic force, and the anchor 2 is anchored on the inner wall of the casing to prevent the pipe string from creeping. When it is necessary to raise and lower the pipe string, the oil pipe pressure is released or the oil casing is connected to make the pressure difference between the oil casing at the hydraulic anchor zero. When the elastic force of the spring piece 6 of the anchor 2 is released, the anchor 2 is pushed back into the anchor hole, and the anchor 2 is automatically recovered into the anchor hole, thereby avoiding the problem of pipe string and tool jamming due to the extension or incomplete recovery of the anchor 2 when drilling.

[0019] According to actual needs, the above-mentioned anti-stuck hydraulic anchor with forced recovery of anchor teeth can be further optimized and / or improved: Embodiment 2: As attached Figure 1 , 2 As shown in Figures 3 and 4, the anchor tooth 2 includes a first straight section 14 and a second straight section 15 which are integrally arranged. The outer diameter of the first straight section 14 is larger than that of the second straight section 15. The first straight section 14 is located at the outer end. The outer sides of the first straight section 14 and the second straight section 15 are both provided with mounting grooves 11. A first sealing ring 7 and a second sealing ring 8 are respectively installed in each mounting groove 11. The size of the first sealing ring 7 is larger than that of the second sealing ring 8.

[0020] By setting a stepped anchor tooth 2 with a larger outer end than an inner end, there is a piston area difference at both ends of the anchor tooth 2. Under the same bottom hole pressure, the thrusts on the inner and outer ends of the anchor tooth 2 are different, and the thrust at the larger end is greater than the thrust at the smaller end, so that the anchor tooth 2 is pushed back into the anchor tooth hole. The greater the bottom hole pressure, the greater the thrust. Under the joint action of the piston pressure difference generated by the spring piece 6 and the stepped anchor tooth 2, the anchor tooth 2 can be more stably retracted into the anchor tooth hole, thereby further avoiding the problem of tool jamming when the drill is free.

[0021] Embodiment 3: As attached Figure 1 , 2As shown, a buffer cavity 9 penetrating inside and outside is provided on the anchor body 1 corresponding to the external position of each anchor tooth 2, a plug 12 is installed at the open end of the buffer cavity 9, and a pressure-conducting hole 10 communicating with the adjacent buffer cavity 9 is provided on the anchor body 1 corresponding to the position between the first sealing ring 7 and the second sealing ring 8.

[0022] When installing the anchor 2, the air between the first sealing ring 7 and the second sealing ring 8 of the anchor 2 is squeezed into the buffer cavity 9 to ensure that the anchor 2 is installed in place.

[0023] Embodiment 4: As attached Figure 1 , 2 As shown, two groups of anchor teeth are arranged at intervals on the left and right sides of the anchor body 1, and each group of anchor teeth includes three anchor teeth holes evenly distributed along the circumference. The two groups of anchor teeth are arranged to ensure stable anchoring.

[0024] Embodiment 5: As attached Figure 1 , 2 As shown in 3, the surface of the anchor tooth 2 is nitrided. This arrangement improves the hardness and anchoring force of the anchor tooth 2.

[0025] The above technical features constitute the embodiments of the present invention, which have strong adaptability and implementation effect. Non-essential technical features can be added or reduced according to actual needs to meet the requirements of different situations.

Claims

1. An anti-stuck hydraulic anchor with forced recovery of anchor teeth, characterized in that The anchor body comprises an anchor tooth, a sand control tube and a pressure strip. Three liquid flow grooves penetrating up and down are arranged on the outer side of the anchor body along the circumference. A penetrating fluid channel is arranged in the middle of the anchor body. At least one group of anchor tooth groups are arranged on the anchor body at intervals on the left and right sides. Each group of anchor tooth groups comprises at least two anchor tooth holes arranged along the circumference. An anchor tooth is arranged in each anchor tooth hole, and the anchor tooth tip faces outward. A sand control tube is threadedly connected on the inner side of the middle of the fluid channel. A slit is arranged on the sand control tube corresponding to the position of each anchor tooth hole. A groove opening outward is arranged on the outer end of each anchor tooth, and a spring sheet is arranged in the groove. A pressure strip capable of pressing the spring sheet is fixedly installed on the anchor body corresponding to the position of the groove.

2. The anti-stuck hydraulic anchor with forced recovery of anchor teeth according to claim 1 is characterized in that The anchor tooth includes a first straight section and a second straight section that are integrally arranged. The outer diameter of the first straight section is larger than that of the second straight section. The first straight section is located at the outer end. The outer sides of the first straight section and the second straight section are both provided with mounting grooves. A first sealing ring and a second sealing ring are respectively installed in each mounting groove. The size of the first sealing ring is larger than that of the second sealing ring.

3. The anti-stuck hydraulic anchor with forced recovery of anchor teeth according to claim 2 is characterized in that A buffer cavity penetrating inside and outside is provided on the anchor body corresponding to the outer position of each anchor tooth, a plug is installed at the open end of the buffer cavity, and a pressure-conducting hole communicating with the adjacent buffer cavity is provided on the anchor body corresponding to the position between the first sealing ring and the second sealing ring.

4. The anti-stuck hydraulic anchor with forced recovery of anchor teeth according to claim 1, 2 or 3, characterized in that Two groups of anchor tooth groups are arranged on the anchor body at intervals on the left and right sides, and each group of anchor tooth groups includes three anchor tooth holes evenly distributed along the circumference.

5. The anti-stuck hydraulic anchor with forced recovery of anchor teeth according to claim 1, 2 or 3, characterized in that The surface of the anchor tooth tip is nitrided.

6. The anti-stuck hydraulic anchor with forced recovery of anchor teeth according to claim 4, characterized in that The surface of the anchor tooth tip is nitrided.

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