CN116411813A - PDC drill bit suitable for hard rock heavy-calibre is carried and is bored coring - Google Patents

Abstract

The invention discloses a PDC drill bit suitable for hard rock large-caliber drilling and coring, which belongs to the technical field of geological drilling and comprises a drill bit body and a drill bit crown connected with the drill bit body, and is characterized in that the bottom of the drill bit crown is provided with a plurality of cutting structures at intervals along the circumferential direction, and each cutting structure comprises a bottom wing and a plurality of bottom surface composite sheets and reinforcing teeth which are specially arranged on the bottom wing; a vertical groove is arranged in the center of the inner wall of each bottom wing, and alloy materials are welded in the groove to form an inner gauge; the periphery of the bit crown is provided with spiral side wings corresponding to the bottom wings, and each side wing is provided with a plurality of side composite sheets and reinforcing teeth to form an outer gauge; a bottom surface and a side surface water tank are arranged between the bottom wing and the side wing of the drill crown, and an elliptical bottom water spraying hole is arranged in the bottom surface water tank. By using the device, the rock crushing efficiency of the hard rock stratum is improved, and the use cost of the drill bit is reduced.

Description

A PDC drill bit suitable for hard rock large-caliber drill core extraction

technical field

The invention belongs to the technical field of geological drilling, and in particular relates to a PDC drill bit suitable for large-caliber drilling core extraction in hard rock.

Background technique

Energy and the environment are two major issues in today's society. As society pays more and more attention to environmental protection, my country has put forward the "double carbon" goal of reaching the peak of carbon emissions by 2030 and achieving carbon neutrality by 2060. Energy Structural adjustment is imperative.

Geothermal energy is the thermal energy stored in the earth. It has the characteristics of large reserves, wide distribution, green and low carbon, recyclable, stable and reliable, and is a feasible and competitive clean energy. The development and utilization of geothermal energy can reduce greenhouse gas emissions and improve the ecological environment. It has become a new direction of energy structure transformation and is of great significance to my country's adjustment of energy structure, ensuring energy security, and achieving the goal of "double carbon".

Coring is the only way to obtain physical data of strata, which is of great significance for understanding the characteristics of underground thermal storage and evaluating and planning geothermal resources. With the exploration, development and utilization of geothermal resources, the exploration, development and utilization of geothermal resources gradually develop to the deep. In the exploration of deep geothermal resources, it is often necessary to drill into rock formations with higher hardness; at the same time, in order to meet the requirements of later test and development and utilization, Geothermal exploration wells are generally designed with a larger diameter. In the large-diameter core drilling of hard rock, the impregnated diamond bit used in the small-caliber hard rock core drilling is used. Due to the large diameter of the drill bit and the thick bottom lip surface, the drilling efficiency is low and the cost of the drill bit is high; while the conventional PDC drill bits are not suitable for hard rock formations.

Contents of the invention

In order to solve the above problems, the present invention has taken the following technical solutions:

A PDC drill bit suitable for large-diameter hard rock drill core extraction, including a drill body, a drill crown connected to the drill body, a plurality of cutting structures arranged at intervals along the circumferential direction at the bottom of the drill crown, each of which The cutting structure includes a bottom wing and a plurality of bottom composite sheets and a plurality of bottom reinforcement teeth arranged on the bottom wing;

A first vertical groove is provided at the center of the inner wall of each bottom wing, and an alloy material is deposited and welded in the first vertical groove;

The periphery of the drill bit crown is provided with a plurality of side wings corresponding to the bottom wing, and each side wing is arranged with a plurality of side composite sheets and a plurality of side reinforcement teeth at intervals;

Bottom water tanks are provided between two adjacent bottom wings, and bottom spray holes are provided in the bottom water tanks, and side water tanks are provided between adjacent two side wings.

Further, the number of the bottom composite sheet and the bottom reinforcement teeth on each bottom wing is the same, and the bottom reinforcement teeth are provided in one-to-one correspondence with the bottom composite sheet along the cutting direction.

Further, a plurality of side composite sheets are arranged on the cutting side of the side flap and located at the bottom of the side flap, and a plurality of side reinforcement teeth are arranged on the side flap around the side composite sheet.

Further, the bottom lip surface profile of the cutting structure is a short parabola.

Further, the multiple bottom composite sheets on each bottom wing are arranged in a pattern.

Further, a second vertical groove is milled near the center of the chip side of the bottom wing, and three bottom composite sheets are arranged on each bottom wing, and two of the bottom composite sheets are arranged on the second vertical groove. On both sides of the groove, one of the bottom composite sheets in the middle is arranged in a retreating manner.

Further, the flanks are helical.

Further, the inner and outer widths of the bottom water tank are equal.

Beneficial effect:

1. The second vertical groove is milled out near the center of the chip side of the bottom surface of the PDC drill designed by the present invention to realize the retreating arrangement of the middle composite sheet on the bottom surface, which is beneficial to protect the middle composite sheet on the bottom surface, increase the stability of the drill bit rotation and improve Rock breaking efficiency.

2. The bottom surface of the PDC bit designed by the present invention is arranged in a font shape to strengthen teeth, which is conducive to improving its protection performance on the bottom composite sheet and improving the impact resistance of the bottom composite sheet.

3. The shape of the flanks of the PDC bit designed by the present invention is designed to be helical, which is conducive to the stability of the drill bit during rotation, thereby reducing the extra impact force on the composite sheet caused by the unstable rotation during the rotation process, and improving the life of the composite sheet. Thereby improving the service life of the drill bit.

4. The inner gauge of the PDC drill bit designed by the present invention adopts welded alloy material, and the side composite sheet and the side reinforcement teeth of the outer gauge are also coated with welded alloy material, which is conducive to improving the gauge performance of the drill bit and improving the performance of the drill bit in hard rock formations. service life.

5. The water tank on the bottom surface of the PDC bit designed by the present invention is designed to be of equal width inside and outside, and the shape of the bottom spray water hole is designed to be elliptical, which is conducive to carrying the cuttings carved by the cutting structure in time.

6. The profile of the bottom lip surface of the PDC bit designed by the present invention is designed as a short parabola, which has better impact resistance and is suitable for use in hard rock formations.

7. The bottom composite sheet and side composite sheet of the PDC bit designed by the present invention all adopt an impact-resistant diamond composite sheet with a composite layer thickness of more than 3mm, and the diamond composite layer of the composite sheet is decobalted, and the decobalt thickness is not less than 0.5mm , to further strengthen the impact resistance of the composite sheet to better meet the drilling needs of hard rock formations.

8. The PDC drill bit designed by the present invention adopts the design of the bottom spray water hole, which reduces the erosion of the core by drilling fluid circulation and is beneficial to protect the core.

Description of drawings

Fig. 1 is a kind of cross-sectional view of the PDC drill bit that is applicable to hard rock large-caliber drilling;

Fig. 2 is a kind of side view of the PDC drill bit that is applicable to hard rock large-caliber drilling;

Fig. 3 is a kind of schematic diagram of the bottom lip surface structure of a PDC drill bit suitable for hard rock large-caliber drilling;

Among them, 1. Drill bit body, 2. Side wings, 3. Bottom lip surface contour, 4. Bottom wing, 5. Bottom spray eye, 6. Bottom water tank, 7. Side water tank, 8. Bottom composite sheet, 9. Bottom surface reinforcement Teeth, 10, side composite sheets, 11, side reinforcement teeth, 12, internal gauge, 13, connecting threaded buckles.

Detailed ways

Example 1

Referring to Fig. 1-Fig. 3, a PDC drill bit suitable for hard rock large-diameter drill core extraction includes a drill bit body 1 and a drill bit crown connected to the drill bit body 1, including:

A plurality of cutting structures arranged at intervals along the circumferential direction at the bottom of the crown of the drill bit, each cutting structure includes a bottom wing 4 and a plurality of bottom surface composite sheets 8 and a plurality of bottom surface reinforcement teeth 9 arranged on the bottom wing 4;

A first vertical groove is milled at the center of the inner wall of each bottom wing 4, and an alloy material is deposited and welded in the first vertical groove;

The periphery of the drill bit crown is provided with a plurality of side wings 2 corresponding to the bottom wing 4, and each side wing 2 is arranged with a plurality of side composite sheets 10 and a plurality of side reinforcement teeth 11 at intervals;

Preferably, the side composite sheet 10 and the side reinforcement teeth 11 are gap-welded with alloy materials to enhance the outer gauge performance.

Bottom water tanks 6 are arranged between adjacent two bottom wings 4 , bottom water tanks 6 are provided with bottom spray eyes 5 , and side water tanks are arranged between adjacent two side wings 2 .

In this embodiment, the number of the bottom composite sheet 8 and the bottom reinforcement teeth 9 on each bottom wing 4 is the same, and the bottom reinforcement teeth 8 and the bottom composite sheet 9 are provided in one-to-one correspondence along the cutting direction.

In this embodiment, a plurality of side composite sheets 10 are disposed on the cutting side of the side flap 2 and located at the bottom of the side flap 2 , and a plurality of side reinforcement teeth 11 are disposed on the side flap 2 around the side composite sheet 10 .

In this embodiment, the upper end of the drill bit body 1 is provided with a connecting threaded button 13 which is a rectangular button for connecting the upper core drilling tool;

In this embodiment, the inner gage 12 is formed by milling the first vertical groove at the center of the inner wall of each bottom wing 4 and the alloy material welded in the first vertical groove;

A plurality of side composite sheets 10 and a plurality of side reinforcing teeth 11 are arranged on the side wings 2 to form an outer diameter gauge.

Preferably, the core body 1 adopts a rigid body, which is convenient for design and processing.

During specific implementation, the bottom surface of the bottom wing 4 first mills out the composite sheet groove, and then inlays the bottom surface composite sheet 8 and the bottom surface reinforcement teeth 9.

In this embodiment, the side composite sheet 10 and the side reinforcement teeth 11 are gap-welded with alloy materials to enhance the performance of outer gauge.

In this embodiment, the bottom lip profile 3 of the cutting structure is in the shape of a short parabola.

This chip structure lip profile has strong impact resistance and is suitable for use in hard rock formations.

In this embodiment, a plurality of bottom composite sheets 8 on each bottom wing 4 are arranged in a pattern.

In this embodiment, a second vertical groove is milled near the center of the chip side of the bottom wing 4, so as to realize the retreating arrangement of the bottom composite sheet 8 in the middle of the bottom lip.

Preferably, the number of bottom composite sheet 8 and bottom reinforcement teeth 9 on each bottom wing 4 is the same, and each bottom composite sheet 8 is provided with one bottom reinforcement tooth 9 behind it.

Preferably, each bottom wing 4 is provided with three bottom composite sheets 8, wherein two bottom composite sheets 8 are arranged on both sides of the second vertical groove, and one bottom composite sheet 8 in the middle is arranged in a retreating manner .

The bottom surface composite sheet 8 in the middle of the bottom wing 4 is arranged in a retreating manner, which is conducive to increasing the stability of the drill bit rotation and improving the rock-breaking efficiency.

Preferably, the bottom spray eye 5 is designed to be oval.

In this embodiment, the side wings 2 are helical, which is beneficial to keep the drill bit stable during rotation, and avoid damage to the composite sheet due to the extra impact caused by the unstable rotation of the drill bit.

Preferably, both the bottom composite sheet 8 and the side composite sheet 10 adopt an impact-resistant diamond composite sheet with a composite layer thickness of more than 3mm, and the diamond composite layer of the composite sheet is decobalted, and the decobalt thickness is not less than 0.5mm, further strengthening The impact resistance of the composite sheet can better meet the needs of drilling in hard rock formations.

In this embodiment, the water tank on the bottom surface has the same width inside and outside, so as to facilitate carrying cuttings carved by the cutting structure.

Preferably, the side water tank 7 is designed in a spiral shape along with the side wings 2 .

The above are only preferred embodiments of the present invention, and do not limit the technical scope of the present invention in any way, so any minor modifications, equivalent changes and modifications made to the above embodiments according to the technical essence of the present invention still belong to The scope of the technical solution of the present invention.

Claims (8)

1. The PDC drill bit suitable for the hard rock large-caliber drilling core extraction comprises a drill bit body and a drill bit crown part connected with the drill bit body, and is characterized in that the bottom of the drill bit crown part is provided with a plurality of cutting structures at intervals along the circumferential direction, and each cutting structure comprises a bottom wing, a plurality of bottom surface composite sheets and a plurality of bottom surface reinforcing teeth, wherein the bottom surface composite sheets and the bottom surface reinforcing teeth are distributed on the bottom wing;

a first vertical groove is formed in the center of the inner wall of each bottom wing, and alloy materials are welded in the first vertical grooves;

the periphery of the drill bit crown is provided with a plurality of side wings which are arranged corresponding to the bottom wings, and each side wing is provided with a plurality of side composite sheets and a plurality of side reinforcing teeth in an interval arrangement manner;

a bottom water tank is arranged between two adjacent bottom wings, bottom water spraying holes are arranged in the bottom water tank, and side water tanks are arranged between two adjacent side wings.

2. The PDC bit of claim 1 wherein the number of the bottom face composite pieces and the bottom face reinforcing teeth on each bottom wing are the same and the bottom face reinforcing teeth and the bottom face composite pieces are arranged in a one-to-one correspondence along the cutting direction.

3. The PDC bit of claim 1 wherein a plurality of side composite blades are disposed on the cutting side of the flank and on the bottom of the flank and a plurality of side reinforcing tooth ring around the side composite blades are disposed on the flank.

4. The PDC bit of claim 1 wherein the bottom lip profile of the cutting structure is a short parabolic shape suitable for hard rock heavy gauge extraction coring.

5. The PDC bit of claim 1 wherein a plurality of the bottom face compacts on each bottom wing are arranged in a delta configuration.

6. The PDC drill bit of claim 5 wherein a second vertical recess is milled near the center of the chip side of the bottom wing, each bottom wing is configured as 3 bottom surface composite pieces, 2 bottom surface composite pieces are disposed on two sides of the second vertical recess, and 1 bottom surface composite piece in the middle is disposed in a back-off manner.

7. The PDC bit of claim 1 wherein the flanks are helical.

8. The PDC bit of claim 1 adapted for hard rock heavy gauge extraction coring wherein the bottom face trough is of equal width inside and outside.

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