Jet compound variable diameter spiral drill bit and drilling method thereof

Abstract

The application discloses a jet flow combined variable-diameter spiral drill bit and a drilling method thereof, and belongs to the technical field of combined drill bits. The application solves the problems of the existing combined drill bit, such as fast drill bit loss and low energy utilization rate caused by single rock breaking structure and fixed mechanical and hydraulic energy distribution mode. The drill bit comprises a drill bit main body, and the drill bit main body comprises a rotating shaft. A double-spiral gradually-changing wing piece structure is arranged on the rotating shaft. The double-spiral gradually-changing wing piece structure comprises a structure main body. A plurality of main spiral wing pieces, a plurality of auxiliary spiral wing pieces and a plurality of nozzles for spraying pulse jet flow are spirally arranged on the structure main body. A sensor assembly is arranged on the drill bit main body. The double-spiral gradually-changing wing piece structure can reduce eccentric wear caused by uneven load in a hard rock section, prevent rock debris accumulation in a soft rock section, improve drilling speed and prolong the service life of the drill bit. Meanwhile, the sensor assembly can collect data in real time, and a controller can dynamically adjust mechanical and hydraulic energy distribution, thereby avoiding energy waste.

Description

Technical Field

[0001] This invention relates to the field of composite drill bit technology, specifically to a jet composite variable diameter auger drill bit and its drilling method. Background Technology

[0002] Existing composite drill bits consist of a single helical blade and a nozzle. In oil drilling, geological exploration, or mining, these bits typically exhibit high mechanical drilling speeds and efficiency when drilling into relatively homogeneous formations with uniform lithology, thanks to their mature design and stable operating modes. However, when encountering complex and variable formation environments, especially in sections where hard and soft rocks frequently alternate, existing composite drill bits, due to their simple rock-breaking structure, are prone to uneven blade wear in hard rock sections due to uneven blade loads, and reduced drilling speed in soft rock sections due to cuttings accumulation. Furthermore, the fixed mechanical and hydraulic energy distribution methods of existing composite drill bits lead to energy waste. Summary of the Invention

[0003] To address the aforementioned problems in the prior art, this invention provides a jet-composite variable-diameter auger drill bit and its drilling method, which solves the problems of rapid drill bit wear and low energy utilization caused by the single rock-breaking structure and fixed mechanical and hydraulic energy distribution method of existing composite drill bits.

[0004] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0005] On one hand, a jet-composite variable-diameter auger drill bit is provided, including a drill bit body. The drill bit body includes a rotating shaft, on which a conical double-helix gradually changing vane structure is arranged. The double-helix gradually changing vane structure includes a structural body, on which multiple main helical vanes, multiple auxiliary helical vanes, and multiple nozzles for jetting pulse jets are spirally arranged. The multiple auxiliary helical vanes and multiple nozzles are respectively located between the cutting teeth of the multiple main helical vanes. A sensor assembly is provided on the drill bit body, and the sensor assembly is signal-connected to a controller for controlling the mechanical and hydraulic energy distribution of the drill bit body.

[0006] In this design, the main helical blade bears the primary rock-breaking load, while the auxiliary helical blade serves as a secondary rock-breaking unit. The nozzle emits pulsed jets between the teeth of the main helical blade. This dual-helix tapered blade structure reduces uneven wear caused by load imbalance in hard rock sections and prevents cuttings accumulation in soft rock sections, thereby increasing drilling speed and extending drill bit life. Simultaneously, data is collected in real-time by sensor components, and the controller dynamically adjusts the distribution of mechanical and hydraulic energy to achieve on-demand energy supply and avoid energy waste.

[0007] Furthermore, the height of each main helical blade gradually decreases along its helical extension direction, while the pitch of each auxiliary helical blade gradually increases along its helical extension direction. The gradually decreasing height of the main helical blades enhances the structural strength of the blades at the drill bit root, reduces stress concentration and uneven wear in hard rock sections, and reduces sliding friction between the main helical blades and the borehole wall. The gradually increasing pitch of the auxiliary helical blades expands the cuttings flow channel, effectively preventing cuttings accumulation in soft rock sections.

[0008] Furthermore, the sensor assembly includes a micro-pressure sensor structure and a vibration acceleration sensor structure. The micro-pressure sensor structure includes a first micro-pressure sensor and two second micro-pressure sensors. The first micro-pressure sensor is located in a blind hole at the root of the main propeller blade. The two second micro-pressure sensors are symmetrically arranged on the side of the main structure. The vibration acceleration sensor structure includes a first vibration acceleration sensor, a second vibration acceleration sensor, and a third vibration acceleration sensor. The first and second vibration acceleration sensors are located in the upper middle part of the main propeller blade and the auxiliary propeller blade, respectively. The third vibration acceleration sensor is located on the rotating shaft. The first micro-pressure sensor is used to collect pressure fluctuations caused by mechanical rock breaking and pressure changes of the pulse jet. The two second micro-pressure sensors are used to monitor mud pressure and compare it with the data from the main monitoring point to eliminate pressure measurement deviations caused by mud flow. The first and second vibration acceleration sensors are located on the main and auxiliary helical blades in the high-frequency regions affected by rock cuttings collisions and mechanical impacts, respectively. They can capture the acceleration peak of the blade "bouncing effect". The third vibration acceleration sensor is used to monitor the torsional and axial vibrations transmitted by the drill pipe. The position of the shaft is less affected by local impacts, and it can obtain the basic signal of the overall vibration of the drill bit body.

[0009] Furthermore, the angle between the axis of each nozzle and the surface of the main structure is 90°. This vertical nozzle design ensures that the pulsed jet impacts the rock surface directly and perpendicularly, enhancing the jet's penetration and fragmentation effect.

[0010] On the other hand, a drilling method for a jet-composite variable-diameter auger drill bit is provided, including the following steps:

[0011] S1. Real-time acquisition of drilling data via sensor components;

[0012] S2. Establish a linear inversion model for DRI, where DRI is the Drillability Rock Index;

[0013] S3. Allocate the proportion of mechanical energy according to the DRI value. The ratio of mechanical energy to hydraulic energy distribution in the drill bit body is set to... ).

[0014] In this scheme, DRI is used to measure rock drillability. It establishes a drillability rock index model by collecting data in real time, and dynamically calculates the mechanical energy ratio based on rock hardness. And set the energy distribution ratio between mechanical and hydraulic power as follows: This allows the drill bit body to increase the proportion of mechanical energy and reduce hydraulic dependence in hard rock sections, and increase the proportion of hydraulic energy in soft rock sections, promoting cuttings removal, dynamically adjusting energy distribution, and avoiding energy waste.

[0015] Furthermore, drilling data includes mechanical rock-breaking pressure. jet pressure Annular mud pressure Axial vibration acceleration Radial vibration acceleration and torsional vibration acceleration .

[0016] Furthermore, the characteristic is that the calculation expression of the DRI linear inversion model is:

[0017]

[0018]

[0019]

[0020] in, and All of these are calibration coefficients, which can be determined experimentally and are easy to implement in drilling equipment, thus improving the practicality and scalability of the method. , , The energy characteristic values ​​of the axial, radial, and torsional vibrations of the drill bit body are respectively. By performing root mean square (RMS) calculation on the vibration acceleration signal using a sliding window, high-frequency noise is eliminated and effective features are extracted. Sampling frequency, The length of the window; The radius from the cutting teeth of the main propeller blade to the center line of the shaft; J is the cutting torque of the drill bit body; J is the moment of inertia of the drill bit body about its axis. This is a constant term.

[0021] Furthermore, the proportion of mechanical energy The allocation expression is:

[0022]

[0023] In this plan, DRI>80, 40 DRI 80 and DRI<40 correspond to hard rock, alternating layers, and soft rock, respectively. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of a jet-type composite variable diameter auger drill bit.

[0025] Figure 2 This is a schematic diagram of a jet-type composite variable diameter auger drill bit.

[0026] Among them: 1. Main propeller blade; 2. Auxiliary propeller blade; 3. Rotating shaft; 4. Nozzle; 51. First micro-pressure sensor; 52. Second micro-pressure sensor; 61. First vibration acceleration sensor; 62. Second vibration acceleration sensor; 63. Third vibration acceleration sensor. Detailed Implementation

[0027] The specific embodiments of the present invention are described below to enable those skilled in the art to understand the present invention. However, it should be understood that the present invention is not limited to the scope of the specific embodiments. For those skilled in the art, various changes are obvious as long as they are within the spirit and scope of the present invention as defined and determined by the appended claims. All inventions utilizing the concept of the present invention are protected.

[0028] Example 1

[0029] This embodiment provides a jet-composite variable diameter auger drill bit, including a drill bit body.

[0030] refer to Figure 1 The drill bit body includes a shaft 3, on which a conical double-helix gradually tapered vane structure is mounted. The double-helix gradually tapered vane structure includes a main body on which multiple main helical vanes 1, multiple auxiliary helical vanes 2, and multiple nozzles 4 for injecting pulse jets are spirally arranged. The auxiliary helical vanes 2 and nozzles 4 are located between the cutting teeth of the main helical vanes 1. The nozzles 4 emit pulse jets between the teeth of the main helical vanes 1. Therefore, the double-helix gradually tapered vane structure can reduce uneven wear caused by load unevenness in hard rock sections and prevent rock cuttings accumulation in soft rock sections, thereby increasing drilling speed and extending drill bit life.

[0031] In this embodiment, the angle between the axis of each nozzle 4 and the surface of the main structure is 90°, ensuring that the jet directly acts on the rock surface to be broken in front of the cutting teeth. At the same time, the nozzle 4 converts the continuous jet into a high-frequency pulsed jet, which enhances the breaking efficiency of soft soil through jet pressure.

[0032] Specifically, the main helical blade 1 is made of high-strength alloy and is used to bear the main rock-breaking load. The blade height of each main helical blade 1 gradually decreases along its helical extension direction. The gradual decrease in the height of the main helical blade 1 enhances the structural strength of the blade at the root of the drill bit, reduces stress concentration and uneven wear in hard rock sections, and reduces the sliding friction between the main helical blade 1 and the borehole wall.

[0033] Specifically, the auxiliary spiral blade 2 is made of high-toughness steel and serves as a secondary rock-breaking unit. The pitch of each auxiliary spiral blade 2 gradually increases along its spiral extension direction. The gradually increasing pitch of the auxiliary spiral blade 2 expands the rock cuttings flow channel and effectively prevents rock cuttings from accumulating in soft rock sections.

[0034] A sensor assembly is installed on the drill bit body, and the sensor assembly is connected to a controller for regulating the mechanical and hydraulic energy distribution of the drill bit body. The sensor assembly collects data in real time, and the controller dynamically adjusts the jet pressure via a micro-valve on nozzle 4, thereby dynamically regulating the mechanical and hydraulic energy distribution of the drill bit body.

[0035] Specifically, the sensor components include a micro-pressure sensor structure and a vibration acceleration sensor structure.

[0036] refer to Figure 2 The micro-pressure sensor structure includes a first micro-pressure sensor 51 and two second micro-pressure sensors 52. The first micro-pressure sensor 51 is located in the root blind hole on the main propeller blade 1; the two second micro-pressure sensors 52 are symmetrically arranged on the side of the main body of the structure.

[0037] The vibration acceleration sensing structure includes a first vibration acceleration sensor 61, a second vibration acceleration sensor 62, and a third vibration acceleration sensor 63. The first and second vibration acceleration sensors 61 and 62 are located in the upper middle part of the main helical blade 1 and the auxiliary helical blade 2, respectively; the third vibration acceleration sensor 63 is located on the rotating shaft 3. The first and second vibration acceleration sensors 61 and 62 are located in the high-frequency region of the main helical blade 1 and the auxiliary helical blade 2, respectively, which are subject to rock cuttings collision and mechanical impact, and can capture the acceleration peak of the blade "bouncing effect". The third vibration acceleration sensor 63 is used to monitor the torsional vibration and axial vibration transmitted by the drill pipe. Furthermore, the position of the rotating shaft 3 is less affected by local impacts, and can obtain the basic signal of the overall vibration of the drill bit body.

[0038] Example 2

[0039] This embodiment is a further limitation based on Embodiment 1. Its purpose is to specifically provide a drilling method for a jet composite variable diameter auger drill bit. Other parts not mentioned refer to Embodiment 1 or the prior art.

[0040] This embodiment provides a drilling method for a jet-composite variable-diameter auger drill bit, including the following steps:

[0041] S1. Real-time acquisition of drilling data via sensor components; drilling data includes mechanical rock-breaking pressure. jet pressure Annular mud pressure Axial vibration acceleration Radial vibration acceleration and torsional vibration acceleration .

[0042] Specifically, the blind hole at the root of the first micro-pressure sensor 51 can directly contact the rock being cut, mainly capturing low-frequency pressure fluctuations generated by mechanical cutting and collecting mechanical rock-breaking pressure. .

[0043] The raw signals collected by the two symmetrically arranged second micro-pressure sensors 52 are ,in ; For annular mud pressure, The pulse frequency is less than 10Hz; For jet pressure, The pulse frequency is 1~10kHz, focusing on capturing the high-frequency pulse pressure generated by the jet impact; by extracting the high-frequency component through a bandpass filter, the pulse can be separated. and .

[0044] The total energy of the jet-composite variable-diameter auger drill bit is provided by both the drill bit drive system (mechanical energy) and the hydraulic system (jet energy), satisfying the expression:

[0045]

[0046] in, Total energy; As mechanical rock-breaking energy, through Calculated; As jet energy, through Acquisition, i.e. , Proportional to the sign, For traffic; This refers to the duration of action. It is controlled by... and Adjustable mechanical energy ratio .

[0047] S2. Establish a linear inversion model for DRI, which stands for Drillability Rock Index, used to measure rock drillability.

[0048] The calculation expression for the DRI linear inversion model is:

[0049]

[0050]

[0051]

[0052] in, and All of these are calibration coefficients, which can be determined experimentally and are easy to implement in drilling equipment, thus improving the practicality and scalability of the method. , , The energy characteristic values ​​of the axial, radial, and torsional vibrations of the drill bit body are respectively. By performing root mean square (RMS) calculation on the vibration acceleration signal using a sliding window, high-frequency noise is eliminated and effective features are extracted. Sampling frequency, The length of the window; The radius from the cutting teeth of the main propeller blade to the center line of the shaft; J is the cutting torque of the drill bit body; J is the moment of inertia of the drill bit body about its axis. This is a constant term.

[0053] S3. Allocate the proportion of mechanical energy according to the DRI value. The ratio of mechanical energy to hydraulic energy distribution in the drill bit body is set to... ).

[0054] mechanical energy percentage The allocation expression is:

[0055]

[0056] In this embodiment, DRI>80, 40 DRI 80 and DRI<40 correspond to hard rock, alternating layers, and soft rock, respectively.

[0057] In summary, the beneficial effects of this plan are as follows:

[0058] 1. Existing composite drill bits, due to their single helical blades and fixed nozzles, are prone to uneven wear in hard rock sections due to uneven blade loads, and reduced drilling speed in soft rock sections due to rock cuttings accumulation. This solution, through a double helical gradient blade structure, can reduce uneven wear caused by uneven loads in hard rock sections and prevent rock cuttings accumulation in soft rock sections, thereby improving drilling speed and extending drill bit life. Together with nozzle 4, it achieves efficient rock breaking across all formations.

[0059] 2. Existing drill bits suffer from energy waste due to the fixed distribution of mechanical and hydraulic energy. This can be addressed by collecting real-time data and establishing a drillability rock index model, while dynamically calculating the proportion of mechanical energy based on rock hardness. And set the energy distribution ratio between mechanical and hydraulic power as follows: This allows the drill bit body to increase the proportion of mechanical energy and reduce hydraulic dependence in hard rock sections, and increase the proportion of hydraulic energy in soft rock sections, promoting cuttings removal, dynamically adjusting energy distribution, and avoiding energy waste.

[0060] 3. Existing composite drill bits with fixed nozzles have limited jet coverage, which easily leads to rock cuttings accumulation, causing problems such as stuck drill bits and borehole wall wear. In this solution, nozzle 4 converts the continuous jet into a high-frequency pulsed jet, which enhances the breaking efficiency of soft soil through jet pressure. It is located between the cutting teeth of the main helical blade 1, thus the main helical blade has a guiding effect, realizing dynamic removal of rock cuttings.

[0061] 4. Existing composite drill bits have an average lifespan of only 50-80 hours due to issues such as blade wear and nozzle clogging. This solution extends the lifespan through structural optimization of the helical gradient blade structure and nozzle position.

[0062] Although specific embodiments of the invention have been described in detail with reference to the accompanying drawings, this should not be construed as limiting the scope of protection of this invention. Various modifications and variations that can be made by those skilled in the art without inventive effort within the scope described in the claims still fall within the scope of protection of this invention.

Claims

1. A drilling method for a jet-composite variable-diameter auger drill bit, characterized in that, The jet composite variable diameter auger drill bit includes a drill bit body, the drill bit body includes a rotating shaft (3), the rotating shaft (3) is provided with a conical double helical gradient vane structure, the double helical gradient vane structure includes a structural body, the structural body is spirally provided with multiple main helical vanes (1), multiple auxiliary helical vanes (2) and multiple nozzles (4) for jetting pulse jets, the multiple auxiliary helical vanes (2) and the multiple nozzles (4) are respectively located between the cutting tooth gaps of the multiple main helical vanes (1); The drill bit body is equipped with a sensor assembly, which is connected to a controller for regulating the mechanical and hydraulic energy distribution of the drill bit body. The sensor assembly includes a micro-pressure sensor structure and a vibration acceleration sensor structure; The micro-pressure sensor structure includes a first micro-pressure sensor (51) and two second micro-pressure sensors (52); the first micro-pressure sensor (51) is located in the root blind hole on the main spiral blade (1); the two second micro-pressure sensors (52) are symmetrically arranged on the side of the main body of the structure. The vibration acceleration sensing structure includes a first vibration acceleration sensor (61), a second vibration acceleration sensor (62), and a third vibration acceleration sensor (63); the first vibration acceleration sensor (61) and the second vibration acceleration sensor (62) are located in the upper middle part of the main rotor blade (1) and the auxiliary rotor blade (2), respectively; the third vibration acceleration sensor (63) is located on the rotating shaft (3); The drilling method of a jet-composite variable-diameter auger drill bit includes the following steps: S1. Real-time acquisition of drilling data via sensor components; the drilling data includes mechanical rock-breaking pressure. jet pressure Annular mud pressure Axial vibration acceleration Radial vibration acceleration and torsional vibration acceleration ; S2. Establish a linear inversion model for DRI, where DRI is the Drillability Rock Index; The calculation expression for the DRI linear inversion model is: in, and All are calibration coefficients; , , These are the energy characteristic values ​​of the axial, radial, and torsional vibrations of the drill bit body, respectively. Sampling frequency, The length of the window; The radius from the cutting teeth of the main propeller blade to the center line of the shaft; J is the cutting torque of the drill bit body; J is the moment of inertia of the drill bit body about its axis. For constant terms; S3. Allocate the proportion of mechanical energy according to the DRI value. The ratio of mechanical energy to hydraulic energy distribution in the drill bit body is set to... .

2. The drilling method of the jet composite variable diameter auger drill bit according to claim 1, characterized in that, The blade height of each main rotor blade (1) gradually decreases along its spiral extension direction, and the pitch of each auxiliary rotor blade (2) gradually increases along its spiral extension direction.

3. The drilling method of the jet composite variable diameter auger drill bit according to claim 1, characterized in that, The angle between the axis of each nozzle (4) and the surface of the main body of the structure is 90°.

4. The drilling method of the jet composite variable diameter auger drill bit according to claim 1, characterized in that, mechanical energy percentage The allocation expression is: .

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