CN105275402A - Particle jet flow-based drill bit for impacting and breaking rocks - Google Patents

Abstract

The invention belongs to the field of petroleum drilling, and particularly relates to a rock-breaking drill bit impacted by a particle jet, which includes a drill body, a drill blade, a nozzle jacket, an inner nozzle and cutting teeth. The nozzle channel connected to the inner cavity of the drill bit, the bottom of the nozzle channel runs through the drill body, the nozzle channel includes the nozzle upper channel and the nozzle lower channel, the inner nozzle is installed in the nozzle lower channel, and the inner nozzle and the nozzle lower channel are arranged The nozzle jacket, the end of the nozzle jacket exposes the bottom of the drill bit body, and three inner nozzles are arranged in the drill bit body, and there is a difference in nozzle diameter. The invention can effectively improve the rock-breaking efficiency of the drill bit and increase the drilling speed of the oil drilling machine. It can prevent the drill bit from deflecting during drilling. Using the special particle jet to impact the roller cone bit can not only improve the drilling speed of the roller cone bit, but also effectively prevent the well deviation.

Description

Particle jet impact rock breaking drill bit

technical field

The invention relates to a particle jet impact rock-breaking drill bit, which belongs to the field of petroleum drilling.

Background technique

With the continuation of oilfield exploration and development, shallow oil resources have been developed, and the focus of oil exploration and development has gradually shifted to deep wells, hard formations, and unconventional oil and gas resources. In the drilling process of these formations, there are problems such as slow drilling speed, easy well deviation, and high drilling costs, which seriously affect the development speed and benefits of deep hard formations and unconventional oil and gas resources. Particle jet drilling technology is one of the effective methods to solve this problem. This technology adds a certain proportion of steel particles to the drilling fluid. The steel particles are carried by the drilling fluid into the downhole drill bit from the drill string. The particles flow from the drill bit After the nozzle is sprayed at high speed, a high-speed particle jet is formed. The high-speed particle jet impacts and breaks the rock, producing a series of impact cracks on the rock surface. After the cracks are generated, the strength of the rock decreases rapidly. The subsequent drill bit can easily break the rock through mechanical action, resulting in large pieces. of broken pieces. By using the particle jet impact combined with the mechanical rock breaking method of the drill bit, the rock breaking efficiency of the drill bit can be effectively improved, and the mechanical speed of oil drilling can be increased. Moreover, during the particle jet drilling process, the drill bit pressure required is much smaller than that of conventional drilling, so the drill bit lateral force generated is much smaller, which can prevent the drill bit from deflecting during the drilling process. Therefore, using the special particle jet to impact the roller cone bit can not only effectively increase the ROP of the roller cone bit, but also effectively prevent the well deviation.

The particle jet drill bit is an important part of the particle jet drilling technology. The efficiency of the particle jet drill bit will directly affect the energy utilization rate of the particle jet drill bit and affect whether the drill bit can achieve efficient mechanical rock breaking. At the same time, the life of the particle jet drill bit is directly related to the entire particle jet drilling technology. Job run time. After the steel particles are added to the drilling fluid, the high-speed particles are ejected from the nozzle to impact and break the rock, realizing the combined rock breaking of the particle jet impact and the drill bit mechanically, and changing the mechanical rock breaking method of the conventional drill bit. How to make full use of the energy of the particle jet, realize the efficient rock breaking of the particle jet, ensure the good cooperation between the particle jet and the mechanical rock breaking of the drill bit, avoid the erosion of the drill bit by the particle jet, and continuously improve the impact efficiency of the particle jet and the life of the drill bit have become key problems to be solved .

Contents of the invention

The technical problem to be solved by the present invention is: to provide a method that can ensure the full use of particle jet energy, realize the efficient rock breaking of the combination of particle jet and drill bit machinery, effectively improve the flow field at the bottom of the well, timely return the particles, and have high erosion resistance. The ability of the particle jet to impact the rock-breaking drill bit.

The particle jet impact rock-breaking drill bit described in the present invention includes a drill body, a drill blade, a nozzle jacket, an inner nozzle and cutting teeth, a drill cavity is arranged on the upper part of the drill body, and a nozzle communicating with the drill cavity is arranged at the bottom of the drill cavity. The flow channel, the bottom of the nozzle flow channel runs through the drill bit body, the nozzle flow channel includes the upper nozzle flow channel and the lower nozzle flow channel, the inner nozzle is installed in the lower nozzle flow channel, and the nozzle jacket is arranged between the inner nozzle and the lower nozzle flow channel, and the nozzle jacket The bottom of the drill bit body is exposed at the end, and three inner nozzles are arranged in the drill bit body, and there are steps in the diameter of the nozzles.

The drill bit is a PDC drill bit structure, and the lower part of the nozzle jacket should protrude from the drill bit body for a certain distance, so as to ensure that the distance between the lower part of the nozzle jacket and the bottom of the well is relatively short. The length of the inner nozzle is longer, ranging from 50mm to 80mm, and the particles can be well accelerated in the inner nozzle under the carrying of the drilling fluid, which ensures that the impact velocity of the particles is basically the same as that of the jet flow. The lower part of the drill body is the drill blade; each nozzle is evenly distributed in the circumferential direction of the drill bit, and each nozzle has a different diameter. By uniformly arranging the nozzles, there are steps in the diameter of the nozzles, which can effectively improve the flow field at the bottom of the hole, and is more conducive to the efficient impact of particles broken rock.

The nozzle casing is connected with the flow channel at the lower part of the nozzle through threads, and the inner nozzle is sintered inside the nozzle casing to form a whole with the nozzle casing.

The nozzle jacket is made of stainless steel, and the inner nozzle is made of hard alloy. The nozzle jacket is made of stainless steel. The nozzle jacket has a large wall thickness, large diameter, and high strength, which can well protect the internal inner nozzle. The inner nozzle is made of hard alloy, which has strong impact resistance and can effectively improve the life of the drill nozzle.

The inner surface of the drill bit is nickel-plated. In order to prevent the erosion and wear of the inner cavity of the drill bit by the particle jet, the contact surface between the particles and the inner cavity of the drill bit is treated with electroless nickel plating to improve the erosion resistance of the inner cavity of the drill bit.

The distance between the end of the nozzle jacket and the bottom of the drill body is 20mm-40mm.

The inner nozzle includes an upper conical section and a lower cylindrical section, the side wall of the conical section is an inwardly concave arc surface, the length of the conical section and the length of the cylindrical section are 1:6, and the inner diameter and wall thickness of the cylindrical section The ratio is 1:4, the inner diameter of the cylindrical section ranges from 7mm to 18mm, and the included angle between the axis of the inner nozzle and the axis of the drill bit body ranges from 0° to 10°. The arc section realizes good shrinkage of particles and drilling fluid, and the cylindrical section of the inner nozzle is longer, and the acceleration distance of particles in the nozzle is longer, which can better realize particle acceleration.

The diameter ratio of the three inner nozzles is 0.95:1.15:1.60, the angle between adjacent inner nozzles is 120°, and the positions of the inner nozzles are evenly arranged.

The drill blades are set to three, the angle between the drill blades is 120°, the back of the drill blades is a plane, the number of cutting teeth on the drill blades is 6-7, and the distance between the bottom of the drill blades and the drill The distance between the bottom of the body is 120-160mm. The number of drill blades is three, and the back of the drill blade is flat, which can better facilitate the upward return of particles after rebounding. The horizontal distance between the blade blades of the drill bit is 30mm-50mm, and the vertical distance is large. Two factors make the space between the blade blades of the drill bit larger, which can ensure that the particles after impacting the rock can be returned in time and smoothly. It can leave the bottom of the well while avoiding the erosion and wear of the bit body.

The beneficial effects of the present invention are:

After the particles are ejected from the drill nozzle at high speed, a high-speed particle jet is formed. The high-speed particle jet impacts and breaks the rock, producing a series of impact cracks on the rock surface. Large chunks of broken pieces. By using the particle jet impact combined with the mechanical rock breaking method of the drill bit, the rock breaking efficiency of the drill bit can be effectively improved, and the mechanical speed of oil drilling can be increased. Moreover, in the process of particle jet drilling, the drilling pressure of the drill bit is much smaller than that of conventional drilling, and the lateral force of the drill bit is much smaller, which can prevent the deflection of the drill bit during the drilling process. Using the special particle jet to impact the roller cone bit can not only improve the drilling speed of the roller cone bit, but also effectively prevent the well deviation.

The back of the drill blade is flat. If the drill blade is arc-shaped, the particles will easily hit the drill blade after impact and rebound, causing erosion to the drill blade. Using a flat drill blade can be more conducive to the upward return of particles. The surface of the inner cavity of the drill bit is treated with electroless nickel plating to improve the erosion resistance of the inner cavity surface of the drill bit and improve the working life of the drill bit.

The wall thickness of the nozzle jacket is large, the diameter is large, and the nozzle strength is high, so the nozzle jacket can effectively protect the inner carbide nozzle from collision damage. In order to increase the space between the blades of the drill bit, facilitate the upward return of particles, and avoid collisions, it is necessary to increase the longitudinal distance between the drill bit body and the bottom of the well; the nozzle jacket and inner nozzle structure are adopted, and the distance between the nozzle jacket and the bottom of the well is larger than that of ordinary PDC drill bits. short. Therefore, after the particle jet is ejected from the drill bit nozzle, the distance to the bottom of the well is smaller than that of the conventional drill bit, which effectively reduces the movement distance of the particle jet to the bottom of the well, thereby reducing the energy loss during the operation of the particle jet and effectively improving the energy of the particle jet. The utilization rate improves the rock-breaking efficiency of the particle jet. At the same time, due to the short distance from the bottom of the well, the movement distance of the particle jet to the bottom of the well is shortened, which effectively avoids the rebound of the particles after impacting the rock and the collision between the subsequent impact particles, and avoids the impact of the collision between particles on the flow field at the bottom of the well. Therefore, the bottom hole flow field of the drill bit is improved, which is more conducive to the upward return of particles and cuttings, and is also conducive to the full use of particle impact energy.

Description of drawings

Fig. 1 is a structural schematic diagram of the present invention.

Fig. 2 is a schematic bottom view of Fig. 1 .

In the figure: 1, drill bit body 2, drill bit blade 3, nozzle jacket 4, inner nozzle 5, cutting teeth 6, drill bit inner chamber 7, nozzle upper flow channel 8, inner nozzle flow channel.

detailed description

The present invention will be further described below in conjunction with accompanying drawing:

As shown in Figures 1 to 2, the particle jet impact rock-breaking drill bit of the present invention includes a drill body 1, a drill blade blade 2, a nozzle outer cover 3, an inner nozzle 4 and a cutting tooth 5, and a drill bit is arranged on the upper part of the drill body 1. Inner cavity 6, the bottom of the drill bit inner cavity 6 is provided with a nozzle flow channel communicating with the drill bit inner cavity 6, the bottom of the nozzle flow channel runs through the drill bit body 1, the nozzle flow channel includes the nozzle upper flow channel 7 and the nozzle lower flow channel, and the inner nozzle 4 is installed on the In the flow channel of the lower part of the nozzle, the inner nozzle flow channel 8 is formed in the inner nozzle 4, and the nozzle outer cover 3 is arranged between the inner nozzle 4 and the lower flow channel of the nozzle. The nozzle 4 has a step difference in the diameter of the inner nozzle 4 . The nozzle outer casing 3 is connected with the flow channel at the lower part of the nozzle through threads, and the inner nozzle 4 is sintered inside the nozzle outer casing 3, and the inner nozzle 4 and the nozzle outer casing 3 form a whole. The nozzle jacket 3 is made of stainless steel, and the inner nozzle 4 is made of hard alloy. The surface of the drill bit inner cavity 6 is nickel-plated. The distance between the end of the nozzle jacket 3 and the bottom of the well is 20 mm to 40 mm. The inner nozzle 4 includes an upper conical section and a lower cylindrical section, the side wall of the conical section is an inwardly concave arc surface, the length of the conical section and the length of the cylindrical section are 1:6, and the ratio of the inner diameter of the cylindrical section to the wall thickness is 1:4, the inner diameter of the cylindrical section ranges from 7mm to 18mm, and the angle between the 4-axis of the inner nozzle and the 1-axis of the drill body ranges from 0° to 10°. The diameter ratio of the three inner nozzles 4 is 0.95:1.15:1.60, the angle between adjacent inner nozzles 4 is 120°, and the positions of the inner nozzles 4 are evenly arranged. There are three drill blades 2, an inner nozzle 4 is arranged between every two adjacent drill blades 2, the angle between the drill blades 2 is 120°, the back of the drill blades 2 is a plane, and the drill blades The number of cutting teeth 5 on the wing 2 is 6-7, and the distance between the bottom of the drill blade blade 2 and the bottom of the drill body 1 is 120-160 mm.

After the mixed liquid enters the drill bit body 1, it first passes through the drill bit inner chamber 6, and then enters the upper flow channel 7 of the nozzle. After being sprayed out from the inner nozzle flow channel 8, it is sprayed from the drill bit body 1 to impact the rock at high speed, realizing the crushing efficiency of the rock. The rock-breaking efficiency of the drill bit is improved. The lower part of the drill body 1 is the drill blade 2, the drill adopts three blades, and the lateral distance between the drill blades is relatively large; the longitudinal distance between the bottom of the drill blade 2 and the bottom of the drill body 1 is large; two aspects The factors make the space between the bit blades 2 larger, which can ensure that the particles after impacting the rock can be returned in time and leave the bottom of the well smoothly, while avoiding the erosion of the drill body 1 and the bit blades 2 wear and tear.

Claims (8)

1. A particle jet impacts a rock-breaking drill bit, comprising a drill bit body (1), a drill bit blade (2), a nozzle overcoat (3), an inner nozzle (4) and a cutting tooth (5), characterized in that: the drill bit body ( 1) The inner upper part of the drill bit cavity (6), the bottom of the drill bit inner cavity (6) is provided with a nozzle flow channel communicating with the drill bit inner cavity (6), the bottom of the nozzle flow channel runs through the drill bit body (1), and the nozzle flow channel includes the upper part of the nozzle The flow channel (7) and the lower flow channel of the nozzle, the inner nozzle (4) is installed in the lower flow channel of the nozzle, the nozzle jacket (3) is arranged between the inner nozzle (4) and the lower nozzle runner, and the end of the nozzle jacket (3) is exposed At the bottom of the drill body (1), three inner nozzles (4) are arranged in the drill body (1), and there is a difference in diameter of the inner nozzles (4). 2. The rock-breaking drill bit impacted by the particle jet according to claim 1, characterized in that: the nozzle jacket (3) is connected to the nozzle lower flow passage through threads, the inner nozzle (4) is sintered inside the nozzle jacket (3), and the inner nozzle (4) and the nozzle jacket (3) form a whole. 3. The particle jet impact rock-breaking drill bit according to claim 1 or 2, characterized in that: the material of the nozzle jacket (3) is stainless steel, and the material of the inner nozzle (4) is cemented carbide. 4. The particle jet impact rock-breaking drill bit according to claim 1, characterized in that: the inner cavity (6) of the drill bit is nickel-plated on the surface. 5. The particle jet impact rock-breaking drill bit according to claim 1, characterized in that the distance between the end of the nozzle casing (3) and the bottom of the drill body (1) is 20 mm to 40 mm. 6. The particle jet impact rock-breaking drill bit according to claim 1, characterized in that: the inner nozzle (4) comprises an upper conical section and a lower cylindrical section, the sidewall of the conical section is an arc surface concave inward, and the conical section The length of the cylindrical section and the length of the cylindrical section are 1:6, the ratio of the inner diameter of the cylindrical section to the wall thickness is 1:4, the inner diameter of the cylindrical section ranges from 7mm to 18mm, and the clamping between the axis of the inner nozzle (4) and the axis of the drill body (1) The angle range is 0°～10°. 7. The particle jet impact rock-breaking drill bit according to claim 1, characterized in that: the diameter ratio of the three inner nozzles (4) is 0.95:1.15:1.60, and the angle between adjacent inner nozzles (4) is 12° °, the positions of the inner nozzles (4) are evenly arranged. 8. The particle jet impact rock-breaking drill bit according to claim 1, characterized in that: the drill blade blades (2) are set to three, and an inner nozzle ( 4), the angle between the drill blades (2) is 120°, the back of the drill blades (2) is flat, the number of cutting teeth on the drill blades (2) is 6-7, and the drill blades (2) ) from the bottom of the drill body (1) to a distance of 120-160mm.