WO2020062741A1

WO2020062741A1 - Efficient composite drill bit suitable for deep well stratum difficult to drill

Info

Publication number: WO2020062741A1
Application number: PCT/CN2019/072903
Authority: WO
Inventors: 刘清友; 曾松; 毛良杰; 王国荣
Original assignee: 西南石油大学; 成都理工大学
Priority date: 2018-09-26
Filing date: 2019-01-24
Publication date: 2020-04-02
Also published as: CN109057715A

Abstract

An efficient composite drill bit suitable for a deep well stratum difficult to drill, comprising a drill bit body (1), a cone (2), and a nozzle anti-blocking mechanism. A fluid cavity (3) is formed in the drill bit body (1). A crown (4) is provided at the bottom of the drill bit body (1). A tapered drill bit (5) is fixedly provided at the center of the bottom surface of the crown (4). A plurality of nozzles (6) distributed around the tapered drill bit (5) is formed on the bottom surface of the crown (4). Each nozzle (6) is communicated with the fluid cavity (3). A plurality of main blades (7) is fixedly provided on the bottom surface of the crown (4) in the circumferential direction of the drill bit body (1). An auxiliary blade (8) is fixedly provided between two adjacent main blades (7). The composite drill bit is compact in structure and low in manufacturing cost, and can improve the rock breaking efficiency, prolong the service life of PDC cutting teeth, and avoid the nozzle from being blocked by rock or debris.

Description

Efficient composite drill bit for deep well difficult to drill formation

Technical field

The invention relates to the technical field of a PDC speed-up bit structure, in particular to a high-efficiency composite bit for deep well difficult to drill formations.

Background technique

DC bit and diamond bit are more and more widely used in petroleum and geological drilling. It can obtain good use effect and good economic benefits in hard formations, and has been widely valued by the petroleum and geological circles. The design of conventional PDC and diamond drills is based on the principle of balanced design, and crown shapes such as deep cones and double cones are used as passive anti-tilt technology. They are applied to the design and play a certain centering and stabilizing role. At present, the PDC bit is mainly composed of a bit body (matrix), PDC cutting teeth, a nozzle, a gauge material, and a connecting body. The PDC cutting teeth are used to cut the ground to achieve drilling. The nozzle is a hydraulic channel between the inner cavity of the bit and the outside. The main role of the nozzle is to clean the bottom of the well, to remove rock cuttings from the bottom of the well, to prevent the mud bit of the drill bit, to reduce repeated cutting, and to improve the efficiency of rock breaking. In addition, there are hydraulic rock breaking effects under certain drilling parameters. During work, the high-speed rotating bit body drives the PDC cutting teeth to rotate at high speed. The PDC cutting teeth cut hard formations, while the fluid ejected from the nozzles expels debris from the well.

However, in the process of cutting hard formations, because the rock is too hard and large in size, the PDC cutting teeth are damaged. The long-term use will also cause the PDC cutting teeth to fatigue and shorten the service life of the drill bit. After the PDC cutting teeth are damaged, they need to be re- Replacing a new drill bit severely reduced the rock breaking efficiency. In addition, during the drilling of hard formations, the debris generated just stuck in the nozzle, causing the fluid flowing into the drill body to be unable to be smoothly ejected from the nozzle, resulting in the PDC cutting teeth not being cooled, and the debris could not be removed. Well discharge, which further reduces rock breaking efficiency.

technical problem

The purpose of the present invention is to overcome the shortcomings of the prior art, and provide an efficient compound formation of deep well difficult to drill formations with compact structure, improved rock breaking efficiency, prolonged PDC cutting tooth life, avoiding nozzles blocked by rocks or debris, and low manufacturing cost. drill.

Technical solutions

The object of the present invention is achieved by the following technical solution: an efficient composite drill bit in deep well difficult to drill formations, comprising a drill bit body, a roller cone and a nozzle anti-blocking mechanism, a fluid cavity is provided in the drill bit body, and a bottom of the drill body is provided with A crown, a cone drill is fixed on the bottom surface of the crown and located at the center thereof; a plurality of nozzles distributed around the cone drill are provided on the bottom surface of the crown, and each nozzle is in communication with the fluid cavity A plurality of main blades are fixed on the bottom surface of the crown and in the circumferential direction of the drill body, and a secondary blade is fixed between two adjacent main blades; There are a plurality of PDC cutting teeth, and a roller is also fixed on the main blade. The roller includes a cone fixed on the top surface of the main blade. The outer surface of the cone is sequentially fixed from the small end to the large end. A circle of insert teeth, disc teeth and milling teeth are provided, and the exposure heights of the insert teeth, disc teeth and milling teeth are greater than the exposure height of the PDC cutting teeth; a fluid cavity is arranged above each nozzle Nozzle anti-blocking mechanism in body, nozzle anti-blocking mechanism package Hollow steel pipe, discharge plate, push plate, spring and plug, the plug is fixed in the nozzle, a guide hole is opened in the plug, and a hollow steel pipe that can move up and down is installed in the guide hole, and the upper end of the hollow steel pipe extends A push plate is welded in the fluid cavity, and the push plate is located in the fluid cavity, the lower end portion of the hollow steel pipe extends into the nozzle, and a discharge plate is welded outside the extension end, and the discharge plate is located in the nozzle, A spring is also sleeved on the hollow steel pipe, one end of the spring is fixed on the bottom surface of the fluid cavity, and the other end of the spring is fixed on the bottom surface of the push plate.

The auxiliary blade is fixed on the bottom surface of the crown, and the auxiliary blade and the main blade are welded together.

The main blades are evenly distributed on the crown.

The crown includes at least three main blade wings.

The discharge plate is arranged parallel to the push plate.

The hollow steel pipe is arranged parallel to the axis of the drill body.

An internal thread is provided in the nozzle, and an external thread is provided on the outside of the plug. The external thread and the internal thread of the plug are connected and fixed on the nozzle.

The cross section of the roller is triangular, semi-circular, trapezoidal or wedge-shaped.

Beneficial effect

The invention has the following advantages: the invention has a compact structure, improves rock breaking efficiency, prolongs the service life of PDC cutting teeth, prevents the nozzle from being blocked by rocks or debris, and has low manufacturing cost.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a half cross-sectional view of the present invention;

Figure 2 is a bottom view of Figure 1;

3 is a schematic cross-sectional view of a roller;

4 is a partially enlarged view of part I in FIG. 1;

In the picture, 1-bit body, 2-roller, 3-fluid cavity, 4-crown, 5-conical drill, 6-nozzle, 7-main blade, 8-secondary blade, 9-PDC cutting tooth , 10-cone, 11-set teeth, 12-disc teeth, 13-milling teeth, 14-hollow steel tube, 15-discharge plate, 16-push plate, 17-spring, 18-plug, 19-guide hole.

Embodiments of the invention

The following further describes the present invention with reference to the accompanying drawings. The protection scope of the present invention is not limited to the following:

As shown in Figures 1 to 4, a high-efficiency composite drill bit in deep well difficult to drill formations includes a drill bit body 1, a roller 2 and a nozzle blocking mechanism. The drill bit body 1 is provided with a fluid cavity 3, and the drill bit body 1 A crown portion 4 is provided at the bottom, and a cone drill bit 5 is fixed on the bottom surface of the crown portion 4 and located at the center thereof. The bottom surface of the crown portion 4 is provided with a plurality of nozzles 6 distributed around the cone drill bit 5, Each nozzle 6 is in communication with the fluid cavity 3, and a plurality of main blades 7 are fixed on the bottom surface of the crown 4 and along the circumferential direction of the drill body 1. The main blades 7 are evenly distributed in this embodiment. The crown 4 includes at least three main blades 7, and the auxiliary blades 8 are fixed between two adjacent main blades 7. A plurality of the main blades 7 are fixed along the length direction. PDC cutting teeth 9.

The main blade wing 7 is also fixed with a roller 2. In this embodiment, the cross section of the roller 2 is triangular, semi-circular, trapezoidal, or wedge-shaped. The roller 2 includes a roller 2 fixed on the top surface of the main blade 7. On the outer surface of the cone body 10, a circle of insert teeth 11, disk teeth 12 and milling teeth 13 are sequentially fixed on the outer surface of the cone body 10 from the small end face to the large end face. The dew-height of the teeth 13 is greater than the dew-height of the PDC cutting teeth 9; a nozzle anti-blocking mechanism located in the fluid cavity 3 is provided above each of the nozzles 6.

The nozzle anti-blocking mechanism includes a hollow steel pipe 14, a discharge plate 15, a push plate 16, a spring 17, and a plug 18. The plug 18 is fixed in the nozzle 6, and a guide hole 19 and a guide hole 19 are opened in the plug 18. A hollow steel pipe 14 that can be moved up and down is installed in the inner slide. The hollow steel pipe 14 is arranged parallel to the axis of the drill body 1. The upper end of the hollow steel pipe 14 extends into the fluid cavity 3, and a push plate 16 is welded at the extended end. The plate 16 is located in the fluid cavity 3, and the lower end portion of the hollow steel pipe 14 extends into the nozzle 6, and the outside of the extended end is welded with a discharge plate 15, the discharge plate 15 is arranged parallel to the push plate 16, and the discharge plate 15 is located at the nozzle In FIG. 6, a spring 17 is also sleeved on the hollow steel pipe 14. One end of the spring 17 is fixed on the bottom surface of the fluid cavity 3, and the other end of the spring 17 is fixed on the bottom surface of the push plate 16.

The auxiliary blade 8 is fixed on the bottom surface of the crown 4, and the auxiliary blade 8 and the main blade 7 are welded together. The nozzle 6 is provided with an internal thread, and the plug 18 is provided with an external thread. The external thread and the internal thread of the plug 18 are connected and fixed on the nozzle 6.

The working process of the present invention is as follows:

Before work, connect the tapered thread head at the upper end of the drill body 1 with the internal thread of the drill rod to install the entire PDC speed-up drill bit; when working, lower the drill rod and rotate it at high speed, and the drill rod drives the PDC speed-up drill bit to rotate at high speed. The PDC speed-up bit was eaten into the hard formation, and the conical drill bit 5 initially crushed the large rock. After the crushing, the milling teeth 13, the disc teeth 12 and the insert teeth 11 further crushed the rock. Finally, the PDC cutting teeth 9 were crushed. Debris is obtained, so the PDC cutting teeth 9 will not directly crush hard large-sized rocks, which protects the PDC cutting teeth, ensures that the PDC cutting teeth can work for a long time, and improves the rock breaking efficiency.

During the drilling process, the worker operates a high-pressure pump on the ground, and pumps high-pressure fluid into the fluid cavity 3 through the high-pressure pump. Some of the high-pressure fluid hits the top surface of the push plate 16, and another part of the high-pressure fluid passes directly through the hollow. The inner cavity of the steel pipe 14 and the nozzle 6 finally act on the bottom of the well, and the fluid reduces the temperature of the PDC cutting teeth to ensure its normal operation. If the debris generated during drilling blocks the nozzle 6, the high-pressure fluid hitting the top surface of the push plate 16 exerts a downward force on the push plate 16 to drive the hollow steel pipe 14 to move downward along the guide hole 19 and compress at the same time The spring 17 further drives the unloading plate 15 to move downwards. The unloading plate 15 discharges the debris stuck in the nozzle 6 downward to the outside of the nozzle 6 and blocks the lower port of the nozzle 6 to prevent the debris from entering into it. Effectively prevents nozzle blockage, thereby ensuring that the PDC cutting teeth can be continuously cooled and further ensuring the smooth progress of rock breaking.

Claims

An efficient composite drill bit for deep well difficult to drill formations, which is characterized in that it comprises a drill bit body (1), a roller (2) and a nozzle anti-blocking mechanism, and a fluid cavity (3) is provided in the drill bit body (1), A crown portion (4) is provided at the bottom of the drill body (1), and a conical drill bit (5) is fixed on the bottom surface of the crown portion (4) and located at the center of the crown portion (4). A plurality of nozzles (6) distributed around the conical drill bit (5) are provided, and each of the nozzles (6) is in communication with the fluid cavity (3). The bottom surface of the crown (4) is along the drill body ( 1) A plurality of main blades (7) are fixed in the circumferential direction, and an auxiliary blade (8) is fixed between two adjacent main blades (7). The main blades (7) are along the length direction of the main blades (7). A plurality of PDC cutting teeth (9) are fixedly fixed, and a roller (2) is also fixed on the main blade (7). The roller (2) includes a cone (10) fixed on the top surface of the main blade (7). ), A ring of teeth (11), disc teeth (12), and milling teeth (13) are sequentially fixed on the outer surface of the cone (10) and from the small end face to the large end face, said insert teeth (11 ) The exposed height of the disc teeth (12) and the milling teeth (13) are greater than the exposed height of the PDC cutting teeth (9); a nozzle located in the fluid cavity (3) is provided above each nozzle (6). Nozzle anti-blocking mechanism. The nozzle anti-blocking mechanism includes a hollow steel pipe (14), a discharge plate (15), a push plate (16), a spring (17), and a plug (18). The plug (18) is fixed to the nozzle ( 6) Inside, the plug (18) is provided with a guide hole (19). A hollow steel pipe (14) that can be moved up and down is slidably installed in the guide hole (19). The upper end of the hollow steel pipe (14) extends into the fluid cavity. (3), and a push plate (16) is welded at the extended end, the push plate (16) is located in the fluid cavity (3), the lower end portion of the hollow steel pipe (14) extends into the nozzle (6), and the A discharge plate (15) is welded on the outside of the extension end, the discharge plate (15) is located in the nozzle (6), and a spring (17) is sleeved on the hollow steel pipe (14). One end of the spring (17) is fixed to the fluid cavity. The bottom surface of the body (3), the other end of the spring (17) is fixed on the bottom surface of the push plate (16).
The high-efficiency composite drill bit for deep well difficult to drill formation according to claim 1, characterized in that the auxiliary blade (8) is fixed on the bottom surface of the crown (4), and the auxiliary blade (8) and the main blade The wings (7) are welded together.
The high-efficiency composite drill bit for deep well difficult to drill formation according to claim 1, characterized in that the main blades (7) are evenly distributed on the crown (4).
The high-efficiency composite drill bit for deep well difficult to drill formation according to claim 1, characterized in that the crown (4) includes at least three main blades (7).
The high-efficiency composite drill bit for deep-hole difficult-to-drill formations according to claim 1, characterized in that the discharge plate (15) is arranged parallel to the push plate (16).
The high-efficiency composite drill bit for deep well difficult to drill formation according to claim 1, characterized in that the hollow steel pipe (14) is arranged parallel to the axis of the drill bit body (1).
The high-efficiency composite drill bit for deep well difficult to drill formation according to claim 1, characterized in that the nozzle (6) is provided with an internal thread, and the plug (18) is provided with an external thread on the outside, and the plug ( 18) The external and internal threads are connected and fixed on the nozzle (6).
The high-efficiency composite drill bit for deep well difficult to drill formation according to claim 1, characterized in that the cross section of the roller (2) is triangular, semi-circular, trapezoidal or wedge-shaped.