Efficient milling shoe for discarded well

Abstract

The utility model belongs to the technical field of oil and gas well engineering equipment, and particularly relates to an efficient grinding shoe for a discarded well, which aims at solving the problems that the existing grinding shoe for the discarded well in the market is low in cutting efficiency, poor in guiding stability, single in grinding function, weak in chip removal capability, insufficient in durability and the like and is difficult to meet the actual operation requirements. The main cone comprises a front guide layer, a main grinding layer and a grinding layer; the main grinding layer comprises hard alloy teeth, main cutting blocks and auxiliary cutting blocks, the hard alloy teeth, the main cutting blocks and the auxiliary cutting blocks are distributed in a staggered mode, the main cutting blocks and the auxiliary cutting blocks are arranged on one side of the main cone and jointly form eagle-beak-shaped asymmetric teeth, and the single sides of the main cutting blocks and the auxiliary cutting blocks are edged. Through the arrangement of the main cone, the front guide layer and other components and the mutual matching relation between the diamond column body of the front guide layer and the main cone, the diamond column body can preliminarily crush obstacles in a discarded well through the posture that the diamond column body inclines forwards by 15 degrees and the included angle between the diamond column body and the central axis of the main cone is 15 degrees.

Description

TECHNICAL FIELD

[0001] The utility model belongs to oil and gas well engineering equipment technical field, concretely relates to a kind of abandoned well high-efficiency shoe. BACKGROUND

[0002] In the field of oil and gas field development, with the continuous promotion of exploitation activities, the number of abandoned wells is rising. Proper handling of abandoned wells is crucial for environmental protection, resource utilization and subsequent new well development.

[0003] Traditional abandoned well treatment faces many problems. There are often complex consolidated obstacles in the wellbore, such as cement plugs, casing fragments and cuttings. These obstacles are mixed together, with significant differences in hardness and structural properties, posing a great challenge to removal work. The grinding shoes used in the past are inefficient in handling such complex situations. Conventional flat-bottomed grinding shoes are not effective in breaking up high-strength obstacles such as casing steel, making it difficult to quickly and effectively break them up, resulting in long operation cycles and high costs. From the perspective of debris removal, the debris removal system of traditional grinding shoes is not perfect. A large amount of debris generated during grinding cannot be removed from the wellbore in a timely and efficient manner, which can cause debris accumulation and repeated grinding. This not only reduces the grinding efficiency of the grinding shoe, but also causes the temperature to rise sharply, seriously affecting the service life of the grinding shoe, and even causing downhole accidents such as sticking, further increasing the risk and cost of the operation.

[0004] In view of the above-mentioned related technology, the inventors found that the existing device has the following defects: the existing device mostly adopts symmetrical teeth or single tooth shape design, the blade angle is unreasonable, which leads to large cutting resistance and fast wear, and cannot realize efficient breaking and grinding. The traditional grinding shoe lacks a spiral forward guide structure, which is easy to deviate or jam during operation, affecting the grinding accuracy, especially in complex well conditions, the guiding ability is insufficient. The grinding layer of the existing device is mostly single material or structure (such as ordinary hard alloy), which cannot meet the grinding needs of different hardness rock layers, and the diamond distribution uniformity is poor, which is easy to cause local wear failure. UTILITY MODEL CONTENTS

[0005] The utility model aims at providing a kind of abandoned well high-efficiency shoe to solve the problems raised in the above background technology.

[0006] To achieve the above-mentioned purpose, the utility model provides the following technical scheme: a kind of abandoned well high-efficiency shoe, including main cone, the main cone includes front guide layer, main grinding layer and grinding layer;The main grinding layer includes staggered hard alloy teeth, main cutting block and vice cutting block, the main cutting block and vice cutting block are arranged on one side of main cone, and jointly constitute eagle beak type asymmetric tooth, the main cutting block and vice cutting block are single-side open blade.

[0007] It is worth mentioning that the hawk beak type asymmetric tooth cooperates with the single side cutting edge to realize differentiated cutting path planning, and the operation efficiency is improved by more than 30%.

[0008] As a preferred embodiment, the front layer includes diamond columns arranged in a spiral around the main cone, the diamond columns are inclined forward by 15°, and the angle between the axis of the diamond columns and the central axis of the main cone is 15°.

[0009] Further, it is worth mentioning that the double 15° angle configuration forms a spiral cutting edge surface, which directionally guides the debris flow to the gap, thereby reducing the risk of secondary wear.

[0010] As a preferred embodiment, the grinding layer includes a tungsten carbide matrix, second grinding blocks of surface sintered diamond, first grinding blocks with a honeycomb microstructure, and third grinding blocks; the second grinding blocks are arranged in a circumferential array with the tungsten carbide matrix as the center and are located away from the mounting hole; the first grinding blocks and the third grinding blocks are both arranged in a circumferential array with the main cone as the axis, and the thickness of the third grinding blocks is 10 mm, and the thickness of the first grinding blocks is 6 mm.

[0011] Further, it is worth mentioning that the 6-10 mm stepped thickness grinding blocks cooperate with the honeycomb embedded drill structure to simultaneously complete the surface roughening and polishing processes.

[0012] As a preferred embodiment, one side of the main cone is provided with a spiral groove and a longitudinal groove; the lead angle of the spiral groove is 45°, and the longitudinal grooves are distributed in a circumferential array with the main cone as the center; the groove depth of the spiral groove and the longitudinal groove is both 8-10 mm, and the groove width is both 15 mm.

[0013] Further, it is worth mentioning that the 45° lead angle spiral groove and the longitudinal groove form a three-dimensional chip removal network, and the chip removal rate is increased to 2.3 times that of the traditional design.

[0014] As a preferred embodiment, the taper angle of the main cone is 70°-80°, and the conical surface is subjected to carburizing hardening treatment.

[0015] Further, it is worth mentioning that the optimized taper angle matches the carburized hardening layer depth of 0.3-0.5 mm, and the surface friction coefficient is reduced to below 0.15.

[0016] As a preferred embodiment, the number of spiral grooves is 3-5, and the spacing between adjacent spiral grooves increases along the axial direction of the main cone; the number of longitudinal grooves is 8-12, and the groove bottom is in the form of a circular arc transition.

[0017] Further, it is worth mentioning that the axial incremental spacing layout combined with the R5 circular arc groove bottom reduces the stress concentration coefficient by 18% and prolongs the fatigue life to 150 hours.

[0018] As a preferred embodiment, the diameter of the diamond column is 5-8mm, the height is 10-15mm, and the diamond column and the tungsten carbide base are fixed by high-temperature brazing.

[0019] Further, it is to be further explained that the length-diameter ratio of 1.25-3.0 is matched with the brazing process at 950℃, and the interface shear strength reaches 350MPa.

[0020] As a preferred embodiment, the pore size of the honeycomb microstructure of the first and third grinding blocks is 0.5-2mm, and diamond particles are embedded in the honeycomb pores; the thickness of the diamond layer of the second grinding block is 3-5mm, and the diamond particle size is 20 / 40 mesh.

[0021] Further, it is to be further explained that the multi-stage honeycomb pore size is adapted to different particle size debris, and the effective utilization rate of diamond is increased to 82%.

[0022] As a preferred embodiment, the height of the main cutting block is 1.2-1.5 times the height of the secondary cutting block, and the blade clearance angle of the main cutting block is 12°-15°, and the blade clearance angle of the secondary cutting block is 8°-10°.

[0023] Further, it is to be further explained that the double-gradient clearance angle design optimizes the cutting force distribution, and the rock breaking depth of the main cutting block reaches 8mm / revolution, and the tool life is extended by 40%.

[0024] Compared with the prior art, the efficient grinding shoe of the disposal well provided by the utility model has at least the following beneficial effects:

[0025] (1) By setting the main cone, the front guide layer and other components, the diamond column and the main cone are matched with each other, so that the diamond column can preliminarily break the obstacles in the disposal well in a posture of 15° forward inclination and 15° included angle with the center axis of the main cone. Further, the device can pre-break and clean the hard obstacles in the screened disposal well through the special design of the front guide layer.

[0026] (2) By setting the main cone, the main grinding layer and other components, the hard alloy teeth, the main cutting block and the secondary cutting block in the main grinding layer are matched with each other, so that the main cutting block and the secondary cutting block can further grind and cut the obstacles treated by the front guide layer through the unilateral blade of the hawk beak type asymmetric tooth structure. Further, the device can efficiently grind and break the obstacles in the screened disposal well which are difficult to process through the unique tooth shape design of the main grinding layer. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 It is a schematic diagram of the overall structure of the utility model.

[0028] Figure 2 It is the partial structure schematic view of the utility model;

[0029] Figure 3 It is the side view schematic view of the utility model;

[0030] Figure 4 It is the bottom structure schematic view of the utility model;

[0031] In the drawing:

[0032] 100, main cone; 101, spiral groove; 102, longitudinal groove; 103, diamond cylinder; 104, tungsten carbide base; 105, first abrasive block; 106, second abrasive block; 107, third abrasive block;

[0033] 200, main cutting block; 201, auxiliary cutting block; 202, mounting hole. DETAILED DESCRIPTION

[0034] Please refer to Figures 1-4 The utility model provides a kind of efficient shoe of abandonment well, including main cone 100, and main cone 100 includes front guide layer, main grinding layer and abrasive layer;Main grinding layer includes staggered distribution hard alloy tooth, main cutting block 200 and auxiliary cutting block 201, main cutting block 200 and auxiliary cutting block 201 are arranged in one side of main cone 100, and jointly constitute eagle beak type asymmetric tooth, and main cutting block 200 and auxiliary cutting block 201 are single-side cutting.

[0035] The efficient shoe of abandonment well is realized high-efficiency grinding operation by the innovative layered cutting structure, and the three-stage design of its main cone 100 has progressive function characteristics: the front guide layer is responsible for preliminary positioning and guiding, the main grinding layer realizes high-strength crushing through the synergistic effect of hard alloy tooth and eagle beak type cutting unit, and the abrasive layer completes final surface leveling, wherein the special configuration of eagle beak type asymmetric tooth is combined with the design of angle complementary and single-side cutting of main cutting block 200 / auxiliary cutting block 201, which not only enhances the impact toughness of cutting unit, but also forms directional cutting track, effectively improves the rock crushing efficiency under complex well conditions, and this composite cutting layout realizes the optimized balance of wear resistance and impact load through the gradient distribution of hard alloy tooth and cutting block base 104 of different hardness materials, especially suitable for abandonment well processing scene with casing residues and formation rock mixture, the structure design of spiral groove 101 and longitudinal groove 102 cooperates with the distribution scheme of diamond cylinder 103, to ensure the synchronous improvement of grinding dust discharge efficiency and cutting stability, and the uniformly distributed first abrasive block 105, second abrasive block 106 and third abrasive block 107 on the surface of tungsten carbide base 104 constitute a multidimensional abrasive system, which realizes reliable connection of tool and drill string in cooperation with the accurate positioning of mounting hole 202.

[0036] Further as Figure 1 shown in the figure, the leading layer comprises diamond pillars 103 arranged in a spiral around the main cone 100, the diamond pillars 103 are inclined forward by 15°, and the angle between the axis of the diamond pillars 103 and the central axis of the main cone 100 is 15°.

[0037] Further as Figure 1 shown in the figure, the grinding layer comprises a circular tungsten carbide substrate 104, second grinding blocks 106 of surface sintered diamond, first grinding blocks 105 and third grinding blocks 107 with honeycomb microstructure; the second grinding blocks 106 are arranged in a circular array around the tungsten carbide substrate 104 and are located on the side away from the mounting hole 202; the first grinding blocks 105 and the third grinding blocks 107 are both arranged in a circular array around the main cone 100, and the thickness of the third grinding blocks 107 is 10 mm, and the thickness of the first grinding blocks 105 is 6 mm.

[0038] Further as Figure 1 shown in the figure, the main cone 100 is provided with a spiral groove 101 and a longitudinal groove 102 on one side; the lead angle of the spiral groove 101 is 45°, and the longitudinal grooves 102 are distributed in a circular array around the main cone 100; the groove depth of the spiral groove 101 and the longitudinal groove 102 is 8-10 mm, and the groove width is 15 mm.

[0039] Further as Figure 1 shown in the figure, the taper angle of the main cone 100 is 70°-80°, and the taper surface is subjected to carburizing hardening treatment.

[0040] Further as Figure 2 shown in the figure, the number of spiral grooves 101 is 3-5, and the spacing between adjacent spiral grooves 101 increases along the axial direction of the main cone 100; the number of longitudinal grooves 102 is 8-12, and the groove bottom is circularly arc-shaped.

[0041] Further as Figure 1 shown in the figure, the diameter of the diamond pillar 103 is 5-8 mm, and the height is 10-15 mm, and the diamond pillar 103 is fixed with the tungsten carbide substrate 104 by high-temperature brazing.

[0042] Further as Figure 1 shown in the figure, the pore size of the honeycomb microstructure of the first grinding block 105 and the third grinding block 107 is 0.5-2 mm, and diamond particles are embedded in the honeycomb holes; the thickness of the diamond layer of the second grinding block 106 is 3-5 mm, and the diamond particle size is 20 / 40 mesh.

[0043] Further as Figure 2As shown, the height of the main cutting block 200 is 1.2-1.5 times the height of the secondary cutting block 201, and the back rake angle of the main cutting block 200 is 12°-15°, and the back rake angle of the secondary cutting block 201 is 8°-10°.

[0044] In summary: first, the spiral diamond column 103 of the leading layer is inclined by 15°+ the central axis is 15°, which first contacts the obstacle such as a cement plug, and forms a composite force field of axial impact+radial cutting when rotating drilling, the 5-8mm diameter diamond column 103 penetrates into the consolidated material with a height of 10-15mm, the spiral arrangement spacing increases along the axial direction to realize spiral propulsion and crushing, and the large obstacle is pre-cracked into 5-10mm fragments to reduce the load of the main grinding layer.

[0045] Secondly, the hawk beak type asymmetric tooth main cutting block 200 of the main grinding layer is 1.2-1.5 times higher than the secondary cutting block 201 cutting into the pre-crushed area, the single-sided cutting design of the main cutting block 200 has a back rake angle of 12°-15°, and the secondary cutting block 201 has a back rake angle of 8°-10° to form an alternating shearing effect, the hard alloy teeth are staggered with the main cutting block 200 / secondary cutting block 201, and when rotating, the main block first shears the hard point such as casing steel, and the secondary block follows to break the weak surface, and the single rotation crushing volume is 1.8 times that of the traditional tooth type, which is particularly suitable for high-strength mixed obstacles.

[0046] Then, the honeycomb microstructure block of the grinding layer has a 0.5-2mm aperture embedded diamond and a 3-5mm thick sintered diamond block on the surface, and the 20 / 40 mesh acts as a relay, and the first grinding block 105 / third grinding block 107 is 6mm / 10mm thick to form a stepped grinding through the thickness difference: the thin block processes 5mm or less debris, and the thick block polishes the well wall; the second grinding block 106 has a circumferential array of 1-3mm hard particles, and the diamond layer is directly ground to 0.1mm or less to avoid the risk of sticking.

[0047] Next, the 45° lead angle spiral groove 1013-5 and the longitudinal groove 1028-12 constitute a double helical chip removal system, the spiral groove 101 generates centrifugal force when rotating to axially transport the debris along the channel with a groove depth of 8-10mm; the longitudinal groove 102 has a groove bottom circular arc transition to eliminate the chip jamming dead angle, and cooperates with the 15mm wide slot to make the rock debris discharge efficiency reach more than 92%, thereby avoiding the temperature rise caused by repeated grinding and reducing the temperature rise by 35℃.

[0048] Finally, the 70°-80° carburized hardening cone surface HRC58-62 forms a dynamic wear-resistant layer during the grinding process. After the wear amount exceeds 1mm, the standby diamond particles in the honeycomb holes are automatically exposed with a pore size of 0.5-2mm design, continuously providing grinding capacity. At the same time, the height difference between the main cutting block 200 and the auxiliary cutting block 201 is 1.2-1.5 times to form a stepped wear compensation, ensuring the stability of the crushing efficiency throughout the service life of the grinding shoe, extending the operation time by 2.5 times compared to the traditional grinding shoe. The first grinding block 105, the second grinding block 106 and the third grinding block 107 uniformly distributed on the surface of the tungsten carbide base 104 constitute a multi-dimensional grinding system, which realizes the reliable connection of the tool and the drill string with the precise positioning of the installation hole 202

[0049] While embodiments of the application have been shown and described, it is to be understood that the embodiments described are merely exemplary and that changes in form and detail can be made without departing from the spirit and scope of the application. The scope of the application is defined by the appended claims and their equivalents.

Claims

1. A high efficiency shoe for abandoned well, comprising a main cone (100), characterized in that, The main cone (100) comprises a leading layer, a main grinding layer and a grinding layer; the main grinding layer comprises staggered distribution of hard alloy teeth, main cutting blocks (200) and auxiliary cutting blocks (201), the main cutting blocks (200) and the auxiliary cutting blocks (201) are arranged on one side of the main cone (100) and jointly form an eagle beak type asymmetric tooth, and the main cutting blocks (200) and the auxiliary cutting blocks (201) are single-sidedly opened.

2. A high efficiency shoe for a disposal well according to claim 1, wherein: The leading layer comprises diamond columns (103) arranged in a spiral around the main cone (100), the diamond columns (103) are inclined forward by 15°, and the angle between the axis of the diamond columns (103) and the central axis of the main cone (100) is 15°.

3. A high efficiency shoe for a disposal well according to claim 1 wherein: The grinding layer comprises a tungsten carbide matrix (104), second grinding blocks (106) of surface sintered diamond, first grinding blocks (105) with a honeycomb microstructure and third grinding blocks (107); the second grinding blocks (106) are arranged in a circumferential array with the tungsten carbide matrix (104) as the center and are located on the side away from the mounting hole (202); the first grinding blocks (105) and the third grinding blocks (107) are both arranged in a circumferential array with the main cone (100) as the center, and the thickness of the third grinding blocks (107) is 10 mm and the thickness of the first grinding blocks (105) is 6 mm.

4. A high efficiency shoe for a disposal well according to claim 1 wherein: One side of the main cone (100) is provided with spiral grooves (101) and longitudinal grooves (102); the lead angle of the spiral grooves (101) is 45°, and the longitudinal grooves (102) are arranged in a circumferential array with the main cone (100) as the center; the groove depth of the spiral grooves (101) and the longitudinal grooves (102) is both 8-10 mm, and the groove width is both 15 mm.

5. A high efficiency shoe for a disposal well according to claim 1 wherein: The taper angle of the main cone (100) is 70°-80°, and the taper surface is subjected to carburizing hardening treatment.

6. A high efficiency shoe for a disposal well according to claim 4 wherein: The number of the spiral grooves (101) is 3-5, and the spacing between adjacent spiral grooves (101) increases along the axial direction of the main cone (100); the number of the longitudinal grooves (102) is 8-12, and the groove bottom is in the form of a circular arc transition.

7. A high efficiency shoe for a disposal well according to claim 2, wherein: The diameter of the diamond column (103) is 5-8 mm, the height is 10-15 mm, and the diamond column (103) is fixed with the tungsten carbide matrix (104) by high-temperature brazing.

8. A high efficiency shoe for a disposal well according to claim 3 wherein: The pore size of the honeycomb microstructure of the first grinding blocks (105) and the third grinding blocks (107) is 0.5-2 mm, and diamond particles are embedded in the honeycomb holes; the thickness of the diamond layer of the second grinding blocks (106) is 3-5 mm, and the diamond particle size is 20 / 40 mesh.

9. A high efficiency shoe for a disposal well according to claim 1 wherein: The height of the main cutting block (200) is 1.2-1.5 times the height of the auxiliary cutting block (201), and the blade edge relief angle of the main cutting block (200) is 12°-15°, and the blade edge relief angle of the auxiliary cutting block (201) is 8°-10°.

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