Reverse circulation sidetracking window opener

Abstract

A reverse circulation sidetracking window opener comprises a connector, a body and a cutting head which are sequentially connected, and is characterized in that the connector, the body and the cutting head are all of a hollow structure, the cutting head comprises a matrix and a cutting body, the matrix is connected with the front end of the body through threads, and the cutting body is connected with the body through threads. The cutting body is composed of a plurality of hard alloy teeth which are circumferentially and uniformly distributed and fixedly embedded at the front end of the matrix; a wear-resistant alloy belt and hard alloy gauge teeth which are arranged front and back are uniformly welded on the outer edge of the body along the circumferential direction, the outer diameter of the hard alloy gauge teeth is greater than that of the body and that of the wear-resistant alloy belt and is equal to that of the cutting body, and the hard alloy gauge teeth are used for continuously grinding the window of the sleeve after windowing; and a conical salvage thread making thread is arranged at the front part of the inner hole of the joint and is used for making a thread for the casing pipe body cut off after windowing. The sidetracking windowing device has the advantages that sidetracking windowing is free of dead points, abrasion to the whipstock is small, windowing drilling jamming can be avoided, windowing milling workload can be greatly reduced, and windowing efficiency and window quality are remarkably improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to a side drilling windowing tool, especially to a reverse circulation side drilling windowing device. BACKGROUND

[0002] The current side drilling windowing tool mainly comprises a milling cone for milling and opening a window in a well and a whipstock for supporting the milling cone to mill a casing until a window is opened, the whipstock serves to support the milling cone to open a window and guide a drill bit into a new wellbore, and the milling cone is an important tool for penetrating a casing and a formation. The milling cone is composed of a milling cone head, a milling cone body and a joint. The outer edge of the milling cone head and the milling cone body is arranged with cutting teeth in a specific manner to optimize the cutting effect, and the milling cone head is provided with a water eye in communication with the inner hole of the milling cone body for circulating drilling fluid to remove the debris generated by milling and cool the cutting teeth. The milling cone works by being supported by the whipstock, and the milling cone is rotated by a drilling tool to cut and mill the casing through the cutting teeth on the milling cone head and the milling cone body. Under the premise that the whipstock is not damaged, the casing on the inclined surface of the whipstock is milled and drilled into the formation to form a window through which a side drilling drill bit can pass in the old wellbore.

[0003] For thick-walled high-strength casing or even multilayer casing windowing, the volume of casing to be milled by the milling cone is large, and multiple milling cones are needed to open a window, which not only reduces the working efficiency, but also easily causes downhole accidents. Because the milling cone can only be used in a positive circulation mode, the debris generated by the milling of the milling cone is returned from the annular space through the outer edge of the milling cone. Since the outer edge of the milling cone is in close contact with the newly cut casing, the accumulation of slightly larger metal debris can cause a stuck drill pipe, resulting in a downhole accident, especially in deep wells. In addition, the center point of various milling cone heads has a linear velocity of zero during the windowing process. When this point passes through the wall of a high-grade casing, there is no cutting force, and a dead point is inevitably formed. Overcoming the dead point not only reduces the windowing efficiency, but also easily causes damage to the whipstock, resulting in windowing failure. It is necessary to adjust the windowing position and lower the whipstock again to open the window. SUMMARY

[0004] The utility model provides a kind of side drilling windowing dead point, and the technical problems to be solved by the utility model are to provide a kind of reverse circulation side drilling windowing device, which is small in wear to whipstock, can avoid windowing stuck drill pipe, can greatly reduce the work load of windowing milling, and significantly improve the efficiency and window quality of windowing.

[0005] To achieve the above object, the utility model adopts the following technical scheme:

[0006] A reverse circulation side drilling windowing device, comprising a joint, a body and a cutting head connected in sequence, wherein the joint, the body and the cutting head are all hollow structures, the cutting head comprises a matrix and a cutting body, the matrix is connected to the front end of the body by screw thread, and the cutting body is composed of a plurality of hard alloy teeth fixedly embedded in the front end of the matrix in a circumferential distribution.

[0007] The outer edge of the body is evenly inlaid with abrasion-resistant alloy strips and hard alloy gage teeth arranged in front and back directions in the circumferential direction, the outer diameter of the hard alloy gage teeth is greater than the outer diameter of the body and the abrasion-resistant alloy strips and equal to the outer diameter of the cutting body, and the hard alloy gage teeth are used for continuously grinding the casing window during the windowing process.

[0008] A tapered fishing thread is arranged at the front part of the inner hole of the joint and is used for making a thread on the casing body cut down after the windowing.

[0009] As a further optimization, the hard alloy teeth include YG hard alloy teeth and YW hard alloy teeth, the YG hard alloy teeth and the YW hard alloy teeth are alternately welded and arranged in the gap at the front end of the body and protrude from the front end of the body, and the front ends of the YG hard alloy teeth and the YW hard alloy teeth are welded by YD hard alloy electrodes.

[0010] As a further optimization, a plurality of auxiliary cutting strips are evenly arranged at the outer edge of the body in the circumferential direction, the auxiliary cutting strips are formed by YD hard alloy overlaying, the outer diameter of the auxiliary cutting strips is slightly greater than the outer diameter of the body and slightly smaller than the outer diameter of the cutting body, and the auxiliary cutting strips are used for protecting the body and repairing the opened casing window.

[0011] As a further optimization, the number of the auxiliary cutting strips is 4-12, and is determined according to the outer diameter of the body.

[0012] As a further optimization, the inner hole diameter of the body is greater than the inner diameter of the body, and an annular shoulder is formed in the body and is used for clamping the cut-down casing body.

[0013] As a further optimization, two radial symmetrical pressure distribution holes are arranged in the middle part of the joint to prevent pump blocking.

[0014] As a further optimization, axial chip removal grooves penetrating the fishing thread are symmetrically arranged at the front part of the inner hole of the joint to facilitate chip removal during the thread making.

[0015] As a further optimization, the abrasion-resistant alloy strips and the hard alloy gage teeth are evenly arranged at the outer edge of the body in 3-6 strips, the width of each abrasion-resistant alloy strip is 10-15 mm, and the width of each hard alloy gage tooth is 8-10 mm.

[0016] The utility model discloses the beneficial effect is:

[0017] 1. Since the joint, the body and the cutting head are all hollow structures, the linear speed of any point on the cutting body arranged at the front end of the cutting head is not zero during the windowing process, so there is no dead point during the windowing, thereby avoiding long-time fixed-point milling to overcome the dead point, and the windowing causes less wear of the whipstock, and the cutting body is always in a continuous cutting state during the windowing process, thereby avoiding drilling blocking and drilling jumping during the windowing, ensuring that the window is regular and smooth, and being beneficial to subsequent operations after the lateral drilling.

[0018] 2. Because the cutting head is hollow, it cuts off a piece of the tube in the shape of a date pit from the sleeve opposite the inclined surface of the guide through the cutting body, unlike the traditional milling taper window opening which grinds away the entire sleeve body. Therefore, it greatly reduces the amount of grinding and milling work, which can improve the efficiency and quality of window opening, and save grinding and milling materials.

[0019] 3. Since the connector, body and cutting head are all hollow structures, reverse circulation of drilling fluid can be achieved when opening the window. That is, drilling fluid is injected through the annular space between the window opener and the downhole casing and returns through the inner hole of the window opener. This not only helps to carry the debris generated during window opening to the surface, but also avoids stuck drill accidents caused by the debris generated during window opening.

[0020] 4. The overall structure is simple, easy to process and maintain. After wear, only the worn cutting head, body or connector needs to be replaced, resulting in low maintenance costs. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of this utility model;

[0022] Figure 2 yes Figure 1 A-direction view.

[0023] Figure 3 yes Figure 2 Enlarged view of part C.

[0024] Figure 4 yes Figure 1 BB cross-sectional view.

[0025] In the figure: 1. Connector; 2. Body; 3. Carbide gauge protection tooth; 4. Wear-resistant alloy strip; 5. Annular shoulder; 6. Carbide body; 7. Secondary cutting strip; 8. Cutting body; 9. Cutting head; 101. Fishing and threading; 102. Pressure dividing hole; 103. Axial chip removal groove. Detailed Implementation

[0026] like Figures 1-4 As shown, this utility model relates to a reverse circulation side-drilling window opener, comprising a connector 1, a body 2, and a cutting head 9 connected in sequence. The connector 1, body 2, and cutting head 9 are all hollow structures. The cutting head 9 includes a tubular matrix 6 and a cutting body 8. The matrix 6 is threadedly fixed to the front end of the body 2. The cutting body 8 is composed of multiple carbide teeth evenly distributed and fixedly embedded in the front end of the matrix 6. Multiple secondary cutting bands 7 are evenly distributed along the circumferential direction on the outer edge of the matrix 6. The secondary cutting bands 7 are made of YD carbide welded together, and their outer diameter is slightly larger than the outer diameter of the matrix 6 and slightly smaller than the outer diameter of the cutting body 8, to protect the matrix 6 and repair the opened casing window.

[0027] The hard alloy teeth include YG hard alloy teeth and YW hard alloy teeth, which are alternately welded in the radial notch at the front end of the matrix 6 and protrude from the front end of the matrix 6, and the front ends of the YG hard alloy teeth and the YW hard alloy teeth are filled and welded on the matrix 6 by YD hard alloy welding rods. The number of the auxiliary cutting bands 7 is 4-12, and is determined according to the outer diameter of the matrix 6. When the outer diameter of the matrix 6 is large, the number of the auxiliary cutting bands can be increased.

[0028] The inner hole of the body 2 is provided with internal threads at both ends, which are used to connect the joint 1 and the cutting head 9; the diameter of the inner hole of the body 2 is larger than the inner diameter of the matrix 6, and an annular shoulder 5 is formed in the body 2 to clamp the cut casing body.

[0029] The outer edge of the body 2 is stepped and the front outer diameter is slightly smaller than the rear outer diameter, and the wear-resistant alloy bands 4 and the hard alloy gauge teeth 3 are evenly embedded and welded on the outer edge of the body 2 in the circumferential direction, which are arranged in front and back, the outer diameter of the hard alloy gauge teeth 3 is larger than the outer diameter of the body 2 and the wear-resistant alloy bands 4 and is equal to the outer diameter of the cutting body 8, which is used to continue to grind the casing window during the windowing process to prevent the body 2 from being worn.

[0030] The wear-resistant alloy bands 4 and the hard alloy gauge teeth 3 are evenly distributed along the outer edge of the body 2, and there are 3-6 of each, wherein the width of each wear-resistant alloy band 4 is 10-15 mm, and the width of each hard alloy gauge tooth 3 is 8-10 mm.

[0031] A tapered fishing and making-up thread 101 is provided in the front part of the inner hole of the joint 1, which is used to make up the casing body cut after windowing. Two radial symmetrical pressure relief holes 102 are provided in the middle of the joint 1 to prevent pump blocking. Axial chip removal grooves 103 are provided symmetrically in the front part of the inner hole of the joint 1, which penetrate the fishing and making-up thread, so as to facilitate chip removal during making up.

[0032] When working, the recoverable near-wall hydraulic whipstock is first fixed in the well at the designed orientation of the window position and the running-in and pulling-out tool is pulled out, and then the reverse circulation side drilling window opener is connected with the drilling tool through the drilling tool thread on the upper end of the joint 1, and is stably lowered to 2 meters above the near-wall whipstock, and the pump is opened for reverse circulation through the square drill pipe on the upper end of the drilling tool, and if the top drive drilling machine directly opens the pump for reverse circulation and rotates the drilling tool at low speed, the cutting body 8 is slowly lowered to the top of the whipstock, and the display will be shown when the cutting body 8 encounters the top of the inclined surface of the whipstock; then the casing is milled at low speed with 5KN drilling pressure, and the drilling footage is increased to 0.5 meters, and then the drilling pressure and the milling speed are gradually increased, and when the casing body against the inclined surface of the whipstock is milled and cut off, that is, the cutting body 8 enters the stratum, the pump pressure is increased, the stratum is continuously milled, the upper part of the cut-off jujube core-shaped casing body is contacted and the fished-up thread is started to increase the drilling pressure, and with the increase of the footage, the jujube core-shaped casing body is gradually fished up and threaded up, that is, the cut-off jujube core-shaped casing body is fished up; then the drilling tool is slowly lifted by 1 meter and is lowered again, and if it can be returned to the original position, it is indicated that the window opening is successful and the cut-off casing body is fished up.

[0033] When working, the recoverable near-wall hydraulic whipstock is first fixed in the well at the designed orientation of the window position and the running-in and pulling-out tool is pulled out, and then the reverse circulation side drilling window opener is connected with the drilling tool through the drilling tool thread on the upper end of the joint 1, and is stably lowered to 2 meters above the near-wall whipstock, and the pump is opened for reverse circulation through the square drill pipe on the upper end of the drilling tool, and if the top drive drilling machine directly opens the pump for reverse circulation and rotates the drilling tool at low speed, the cutting body 8 is slowly lowered to the top of the whipstock, and the display will be shown when the cutting body 8 encounters the top of the inclined surface of the whipstock; then the casing is milled at low speed with 5KN drilling pressure, and the drilling footage is increased to 0.5 meters, and then the drilling pressure and the milling speed are gradually increased, and when the casing body against the inclined surface of the whipstock is milled and cut off, that is, the cutting body 8 enters the stratum, the pump pressure is increased, the stratum is continuously milled, the upper part of the cut-off jujube core-shaped casing body is contacted and the fished-up thread is started to increase the drilling pressure, and with the increase of the footage, the jujube core-shaped casing body is gradually fished up and threaded up, that is, the cut-off jujube core-shaped casing body is fished up; then the drilling tool is slowly lifted by 1 meter and is lowered again, and if it can be returned to the original position, it is indicated that the window opening is successful and the cut-off casing body is fished up.

[0034] For soft stratum, the cut-off casing body can not be fished up by the fished-up thread, and the drilling footage in the stratum needs to be appropriately increased, so that the lower end of the cut-off jujube core-shaped casing body passes through the annular shoulder 5 in the body 2, and the cut-off jujube core-shaped casing body is necessarily inclined in the body, so that the lower end of the cut-off jujube core-shaped casing body is clamped at the annular shoulder 5, and thus the cut-off jujube core-shaped casing body can also be taken to the bottom.

[0035] The above is only the preferred specific implementation manner of the present application, but the protection scope of the present application is not limited to this, any skilled person in the art can make equivalent replacement or change according to the technical scheme and the inventive concept of the present application within the technical range disclosed by the present application, which should be covered in the protection scope of the present application.

Claims

1. A reverse circulation sidetracking window mill comprising a joint, a body and a cutting head connected in sequence, characterized in that: The joint, the body and the cutting head are all hollow structures, the cutting head comprises a matrix and a cutting body, the matrix is connected with the front end of the body through threads, and the cutting body is composed of a plurality of hard alloy teeth fixedly embedded in the front end of the matrix in a circumferential distribution manner; A wear-resistant alloy strip and a hard alloy gage tooth are symmetrically embedded and welded on the outer edge of the body in a circumferential direction, the hard alloy gage tooth has an outer diameter greater than the outer diameters of the body and the wear-resistant alloy strip and equal to the outer diameter of the cutting body, and is used for continuously grinding the casing window during the windowing process; A tapered fishing and threading tap is arranged at the front part of the inner hole of the joint, and is used for threading the cut casing body after the windowing.

2. The underreamer of claim 1, wherein: The hard alloy teeth comprise YG hard alloy teeth and YW hard alloy teeth, the YG hard alloy teeth and the YW hard alloy teeth are alternately welded and arranged in the gap at the front end of the matrix and protrude from the front end of the matrix, and the front ends of the YG hard alloy teeth and the YW hard alloy teeth are welded through YD hard alloy welding rods.

3. The underreamer of claim 1, wherein: A plurality of auxiliary cutting strips are symmetrically arranged on the outer edge of the matrix in a circumferential direction, the auxiliary cutting strips are formed by YD hard alloy overlay welding, have an outer diameter slightly greater than the outer diameter of the matrix and slightly less than the outer diameter of the cutting body, and are used for protecting the matrix and repairing the opened casing window.

4. The underreamer of claim 3, wherein: The number of the auxiliary cutting strips is 4-12, and is determined according to the outer diameter of the matrix.

5. The underreamer of claim 1, wherein: The inner hole diameter of the body is greater than the inner diameter of the matrix, and an annular shoulder is formed in the body, and is used for clamping the cut casing body.

6. The underreamer of claim 1, wherein: Two radial symmetric pressure distribution holes are arranged in the middle part of the joint, so as to prevent the pump from being blocked.

7. The underreamer of claims 1 or 6, wherein the underreamer further comprises a second cutting element disposed on the second cutting element support. 5 An axial chip removal groove penetrating the fishing and threading tap is symmetrically arranged at the front part of the inner hole of the joint, so as to facilitate chip removal during threading.

8. The underreamer of claim 1, wherein: The wear-resistant alloy strip and the hard alloy gage tooth are respectively distributed in 3-6 strips along the outer edge of the body, each wear-resistant alloy strip has a width of 10-15 mm, and each hard alloy gage tooth has a width of 8-10 mm.

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