Composite drill bit

Abstract

The utility model provides a combined type drill bit which comprises a tricone bit and a casing milling barrel, the tricone bit and the casing milling barrel are both fixedly connected to the end of a drill column, the tricone bit is located in the casing milling barrel, and a casing milling head is integrally formed and connected to the end of the casing milling barrel. The tricone bit comprises a main body, chain wheels and cones, the three cones are connected with the chain wheels through chain wheel shafts respectively, bearings are arranged between the cones and the chain wheels, a mounting seat is fixedly arranged in the main body, the three chain wheels are rotatably mounted on the mounting seat, a drilling fluid channel is formed in the main body, an outlet of the drilling fluid channel is communicated with a water hole, and a lubricating grease storage cavity is formed in the main body. And the lubricating grease storage cavity is communicated with the bearing mounting cavity. According to the structural design, the drill bit and the casing milling barrel are integrated, the roller bit rolls to crush materials at the bottom of the well during drilling and grinding of the bottom of the well, the peripheral casing milling head slides to crush materials on the wall of the well, the wall of the drilled hole is fully protected, the manufacturing cost is low, and application and popularization can be achieved.

Description

TECHNICAL FIELD

[0001] The utility model relates to a drill bit for drilling and milling in complex downhole accident treatment, in particular to a composite drill bit. BACKGROUND

[0002] In the middle and late stage of oil exploitation, well repair or accident well treatment needs well repair operation, and the roller bit or the drag bit is often used in the drilling and milling operation in the well, and the conventional drill bit cannot reach the effect of fast footage and scraping the casing wall. Therefore, a more reasonable composite drill bit with more complete functions and better use effect needs to be designed. UTILITARY MODEL

[0003] The utility model provides a composite drill bit, the device structure design is scientific and reasonable, and the characteristics of the roller bit and the drag bit are fully combined, the function can be effectively expanded, the broken range is expanded and the well wall is trimmed on the basis of broken footage, the use effect is good, the manufacturing cost is low, the practicality is strong, and the utility model can be popularized and used.

[0004] To solve the above technical problems, the utility model adopts the technical scheme of a composite drill bit, characterized by comprising a three-roller bit and a milling sleeve, the three-roller bit and the milling sleeve are fixedly connected at the end of the drill string, the three-roller bit is located in the milling sleeve, a wedge-shaped milling head is integrally connected at the end of the milling sleeve, and the milling head is made of hard alloy.

[0005] The three-roller bit comprises a main body, a roller disc and rollers, the rollers are connected to the roller disc through roller shafts, bearings are arranged between the rollers and the roller disc, an installation seat is fixedly arranged in the main body, the roller discs are rotatably installed on the installation seat, a drilling fluid channel is arranged in the main body, the outlet of the drilling fluid channel is connected to a water eye, the inlet of the drilling fluid channel is connected to a drilling fluid conveying pipe on the drill string, the water eye sprays drilling fluid to clean the broken bottom material and cool the drill bit, a grease storage cavity is arranged in the main body, the grease storage cavity is connected to the bearing installation cavity, and the bearing is fully lubricated by the grease stored in the grease storage cavity.

[0006] Preferably, the water eye is arranged at the center of the main body, the rollers are arranged in a ring array around the water eye, the drilling fluid channel is arranged below the water eye on the main body, a lower gasket is arranged on the water eye, and an upper gasket is connected to the lower gasket.

[0007] Preferably, the wall thickness of the sleeve milling cylinder is 4mm, the tooth disc extends out of the sleeve milling cylinder, the cone is a semispherical type, the cone is provided with multiple layers of grinding teeth arranged in a concentric circle layer by layer, the grinding teeth are wedge-shaped teeth, and the cone is provided with a bearing race shoulder matched with a bearing.

[0008] Compared with the prior art, the utility model has the following advantages:

[0009] 1、The utility model discloses a scientific and reasonable design, and fully combines the characteristics of the roller bit and the drag bit, effectively expands the implementable function, enlarges the crushing range through the sleeve milling cylinder on the basis of the crushing footage and has the trimming effect on the well wall, has good use effect, low manufacturing cost and strong practicality, and can be widely used.

[0010] 2、The utility model discloses a scientific and reasonable design, and fully combines the characteristics of the roller bit and the drag bit, effectively expands the implementable function, enlarges the crushing range through the sleeve milling cylinder on the basis of the crushing footage and has the trimming effect on the well wall, has good use effect, low manufacturing cost and strong practicality, and can be widely used.

[0011] The utility model will be further explained in detail in connection with the drawings and examples. DRAWINGS

[0012] Figure 1 It is the structure schematic diagram of the utility model.

[0013] Figure 2 It is the structure schematic diagram of the first support rod of the utility model.

[0014] Mark explanation:

[0015] Specific implementation

[0016] As Figure 1 And Figure 2 The utility model discloses a three-cone drill bit and sleeve milling cylinder 13, three-cone drill bit and sleeve milling cylinder 13 all are fixedly connected at the end of drill string, three-cone drill bit is located in sleeve milling cylinder 13, the end of sleeve milling cylinder 13 is integrally connected with sleeve milling head 4 of wedge shape, and the sleeve milling head is made of hard alloy.

[0017] The three cone drill bit comprises a main body 1, a cone disc 5 and three cone wheels 8, the three cone wheels 8 are connected to the cone disc 5 through cone wheel shafts 11 respectively, bearings 12 are arranged between the cone wheels 8 and the cone disc 5, a mounting seat 2 is fixedly arranged in the main body 1, the three cone discs 5 are rotatably mounted on the mounting seat 2, a drilling fluid channel 6 is arranged in the main body 1, an outlet of the drilling fluid channel 6 is communicated with a water eye 3, an inlet of the drilling fluid channel 6 is connected to a drilling fluid conveying pipe on a drill string, the water eye 3 sprays out drilling fluid to clean broken bottom-hole materials and cool the drill bit, a lubricating grease storage cavity 9 is arranged in the main body 1, the lubricating grease storage cavity 9 is communicated with a bearing mounting cavity, the bearing is fully lubricated by the lubricating grease stored in the lubricating grease storage cavity and flowing into the bearing mounting cavity.

[0018] In the embodiment, the water eye 3 is located at the center of the main body 1, the three cone wheels 8 are arranged in a ring array with the water eye 3 as the center, the drilling fluid channel 6 is arranged below the water eye 3 on the main body 1, a lower gasket 7 is arranged on the water eye 3, and an upper gasket 10 is connected to the lower gasket 7 in a matching mode.

[0019] In the embodiment, the wall thickness of the sleeve milling barrel 13 is 4 mm, the cone disc 5 extends out of the sleeve milling barrel 13, the cone wheel 8 is a semi-spherical type, a plurality of layers of abrasive teeth are arranged on the cone wheel 8 in a nested mode according to concentric circles, the abrasive teeth are wedge-shaped teeth, and a bearing runway shoulder that cooperates with the bearing 12 is arranged in the cone wheel 8.

[0020] In use, the drilling pressure acts on the rock through the abrasive teeth, the cone wheel rolls to make the abrasive teeth staggered contact with the single-tooth and double-tooth at the bottom of the well, which causes the cone wheel to exchange up and down at the center position, so that the drill bit makes up-and-down reciprocating motion along the axis, that is, longitudinal vibration. This makes the drill string continuously compress and stretch, and generates an impact load, which together with the static load pressure generated by the drilling pressure forms an impact and crushing effect on the formation rock, which is the main way to break the rock. When the three cone drill bit works, the overtop and compound cone can make the teeth slide in the tangential direction, which can break the rock in the tangential direction together with the impact and crushing effect, and can also shear off the rock between the broken pits of adjacent teeth in the same tooth ring; in addition to the axial sliding and cutting effect on the formation, the radial sliding generated by the shift shaft can shear off the rock between the tooth rings, and the tangential sliding together with the tangential sliding generated by the overtop and compound cone can shear off the rock between the broken pits in the same tooth ring. The sleeve milling barrel 13 and the three cone drill bit rotate with the rotation of the drill string, the sleeve milling barrel 13 can expand the broken range and has a trimming effect on the well wall, and when the three cone drill bit rotates as a whole, each cone wheel 8 rotates by itself when it is pressed and broken, and the drilling fluid channel 6 continuously sprays out high-pressure drilling fluid to cool the cone wheel 8 and clean the accumulated cuttings.

[0021] The above is only the preferred embodiment of the present application, and does not limit the present application. Any simple modification, change and equivalent change of the above embodiment according to the technical essence of the present application still belong to the protection scope of the technical scheme of the present application.

Claims

1. A combination drill bit, comprising: The three cone drill bit and the sleeve milling barrel (13) are fixedly connected at the end of the drill string, the three cone drill bit is located in the sleeve milling barrel (13), and the sleeve milling head (4) is integrally formed at the end of the sleeve milling barrel (13); The three cone drill bit comprises a main body (1), a tooth disc (5) and a cone (8), three tooth discs (5) are connected to the tooth disc (5) through a cone shaft (11), a bearing (12) is arranged between the cone (8) and the tooth disc (5), an installation seat (2) is fixedly arranged in the main body (1), three tooth discs (5) are rotatably installed on the installation seat (2), a drilling fluid channel (6) is arranged in the main body (1), the outlet of the drilling fluid channel (6) is communicated with a water eye (3), the inlet of the drilling fluid channel (6) is connected with a drilling fluid conveying pipe located on the drill string, and a lubricating grease storage cavity (9) is arranged in the main body (1) and communicated with the bearing (12) mounting cavity.

2. The combination drill bit of claim 1 wherein, The water eye (3) is located at the center of the main body (1), three cones (8) are arranged in an annular array with the water eye (3) as the center, the drilling fluid channel (6) is arranged below the water eye (3) on the main body (1), the lower gasket (7) is arranged on the water eye (3), and the upper gasket (10) is connected to the lower gasket (7) in a matched mode.

3. The combination drill bit of claim 1 wherein, The wall thickness of the sleeve milling barrel (13) is 4mm, the tooth disc (5) extends out of the sleeve milling barrel (13), the cone (8) is a semispherical type, a plurality of layers of grinding teeth are arranged on the cone (8) in a concentric circle layer-by-layer nesting mode, the grinding teeth are wedge-shaped teeth, and the cone (8) is provided with a bearing runway shoulder matched with the bearing (12).

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