A drilling tool for negative pressure transport of drill cuttings and a method of using the same

Abstract

The application discloses a drilling tool for transporting drill cuttings under negative pressure and a use method thereof. The drilling tool comprises a drill bit, a mounting opening is arranged at the bottom end of the drill bit, a plurality of blades are arranged on the side wall of the drill bit, main cutting teeth are arranged at the top end of the blades, positive helical cutting teeth are arranged on the upper middle part of the blades, auxiliary cutting teeth B are arranged on the lower middle part of the blades, negative helical cutting teeth are arranged at the bottom end of the blades, and main chip removal holes are arranged between adjacent auxiliary cutting teeth B; auxiliary cutting teeth A are arranged at the top end of the drill bit, auxiliary chip removal holes are arranged at the bottom end of the auxiliary cutting teeth A, the main chip removal holes and the auxiliary chip removal holes are in communication with the mounting opening at the bottom end of the drill bit, and the use method comprises the following steps: S1, sequentially connecting the drill bit, a drill rod, a gas-electric combined slip ring and a negative pressure pipeline; S2, cutting the coal body by using the drill bit to complete the drilling operation of the first drill rod; S3, increasing a second connecting multi-channel negative pressure chip guide drill rod to continue the drilling operation; and S4, after the drilling cuttings measurement is completed, disassembling all the components.

Description

Technical Field

[0001] This invention relates to the field of geological exploration, and in particular to a drilling tool for transporting drill cuttings under negative pressure and its method of use. Background Technology

[0002] The drill cuttings method is a manual method for predicting rockbursts. It refers to the preliminary assessment of the potential hazard level of rockbursts and is a commonly used method for preventing rockburst disasters. Currently, when conducting drill cuttings method construction on site, handheld drilling rigs are commonly used with twist drill rods and corresponding drill bits to drill holes. During the drilling process, the helical structure of the twist drill rod is used to remove drill cuttings from the borehole. Parameters such as the amount of drill cuttings per meter of borehole, drill cuttings particle size, and drill cuttings temperature are recorded and analyzed, thereby enabling the prediction of the rockburst hazard at the work site.

[0003] During drill cuttings collection, there are frequent instances of drill cuttings loss and accumulation, making it impossible to accurately reflect the amount of drill cuttings per meter. For example, the coal seam in shallow boreholes is often fragmented, and the contact between the drill cuttings collection sleeve and the borehole wall is poor, leading to some drill cuttings loss during collection. The helical structure of the twist drill rod has a cuttings guiding function, but it also cuts the borehole wall during drilling. As the drilling depth increases, the cutting amount also increases, and the cut drill cuttings are also guided out of the borehole by the helical structure, thus increasing the amount of drill cuttings per meter and affecting the prediction of impact hazards at the work site. Because the contact area between the helical structure of the twist drill rod and the drill cuttings is large, and the helical structure provides a propulsive force into the coal seam when the twist drill rod rotates forward, when the coal seam stress is high, the generated drill cuttings... When the amount of cuttings is large, "drill jamming" or even "drill suction" can occur, causing the drill rod to remain in the borehole, affecting the construction of the cuttings hole and causing certain economic losses. The spiral structure of the twist drill rod results in a relatively long transport path for the cuttings. At the same time, the twist drill rod will grind up larger cuttings during the cuttings guiding process, which will affect the accuracy of the impact hazard analysis results from the perspective of particle size. Regarding the cuttings temperature, field measurements have found that the cuttings temperature in shallow boreholes changes significantly. As the borehole depth increases, the cuttings temperature decreases and tends to stabilize. This phenomenon occurs because as the borehole depth increases, the cuttings transport path increases, and the long-distance transport of cuttings will cause the temperature to assimilate with the borehole wall. Therefore, it will affect the accuracy of the impact hazard analysis results from the perspective of cuttings temperature.

[0004] The aforementioned problems are mainly caused by the structure of the drill bit and drill rod and the method of chip removal. In order to solve these problems, ensure the accuracy of the cuttings removal method, and provide guidance for safe production in coal mines, it is necessary to develop a drilling tool that can transport cuttings under negative pressure. Summary of the Invention

[0005] The purpose of this invention is to address the above-mentioned problems by providing a drilling tool for negative pressure transport of drill cuttings that has a simple structure and improves the accuracy of rockburst prediction, as well as its method of use.

[0006] To achieve the above objectives, the technical solution of the present invention is as follows:

[0007] A drilling tool for negative pressure transport of drill cuttings includes a drill bit and a drill rod. One end of the drill bit is connected to the drill rod, and the other end of the drill rod is connected to a negative pressure pipeline. The drill bit is cylindrical, with a hollow cavity inside. The bottom end of the hollow cavity communicates with an installation opening at the bottom of the drill bit. Several blades are arranged along the circumference of the drill bit on its sidewall. The blades have a main cutting tooth at their tip, located at the top of the drill bit. A positive helical cutting tooth is located at the upper middle part of the blade, and an auxiliary cutting tooth is located at the lower middle part of the blade. The drill bit has an auxiliary cutting tooth B with a reverse helical cutting tooth at its bottom end, and a main chip removal hole between adjacent auxiliary cutting teeth B. A protruding hemispherical sphere is located at the center of the drill bit's tip, and an auxiliary cutting tooth A is positioned at the top of the hemispherical sphere. Auxiliary cutting tooth A is inclined, and an auxiliary chip removal hole is located at its bottom end, with the axis of the auxiliary chip removal hole aligned with the inclination direction of the auxiliary cutting tooth A. Both the main chip removal hole and the auxiliary chip removal hole are connected to the hollow cavity inside the drill bit. The drill bit is connected to the drill rod through an installation opening.

[0008] Furthermore, a temperature sensor is provided on one side of the blade tip, and the temperature sensor is electrically connected to the signal line amplification contact A located at the bottom of the blade.

[0009] Furthermore, the drill rod includes a tail-end multi-channel negative pressure cutting drill rod; there is one tail-end multi-channel negative pressure cutting drill rod, one end of which is connected to the drill bit, and the other end of which is connected to the negative pressure pipeline.

[0010] Furthermore, the drill pipe also includes a multi-channel negative pressure chip guide drill pipe, which is disposed between the drill bit and the tail multi-channel negative pressure chip guide drill pipe. There are several multi-channel negative pressure chip guide drill pipes connected end to end. One end of the multi-channel negative pressure chip guide drill pipe after the end is connected to the drill bit, and the other end of the multi-channel negative pressure chip guide drill pipe after the end is connected to the tail multi-channel negative pressure chip guide drill pipe.

[0011] Furthermore, both the connecting multi-channel negative pressure chip guide drill rod and the tail multi-channel negative pressure chip guide drill rod are triangular prisms, and positive spiral grooves are provided on the three edges of both the connecting multi-channel negative pressure chip guide drill rod and the tail multi-channel negative pressure chip guide drill rod; a through hole is provided at the center of the connecting multi-channel negative pressure chip guide drill rod and the tail multi-channel negative pressure chip guide drill rod, the axis of the through hole is consistent with the axis of the connecting multi-channel negative pressure chip guide drill rod, and an auxiliary air supply channel and a signal transmission channel are provided outside the through hole, both of which penetrate the connecting multi-channel negative pressure chip guide drill rod and the tail multi-channel negative pressure chip guide drill rod; signal line amplification contacts B are provided at both ends of the connecting multi-channel negative pressure chip guide drill rod and the tail multi-channel negative pressure chip guide drill rod along their length, and the signal line amplification contacts B are located at both ends of the signal transmission channel, and a signal amplification contact is provided inside the signal transmission channel. Both ends of the signal line are connected to the signal line amplification contacts B located at both ends of the signal transmission channel. When the connecting multi-channel negative pressure chip guide drill rod and the tail multi-channel negative pressure chip guide drill rod are connected to the drill bit, the through holes and auxiliary air supply channels between the tail multi-channel negative pressure chip guide drill rod and the connecting multi-channel negative pressure chip guide drill rod, and between adjacent connecting multi-channel negative pressure chip guide drill rods, are connected. The signal line amplification contacts B between the tail multi-channel negative pressure chip guide drill rod and the connecting multi-channel negative pressure chip guide drill rod, and between adjacent connecting multi-channel negative pressure chip guide drill rods, are in contact with each other. The through holes on the connecting multi-channel negative pressure chip guide drill rod are connected to the mounting opening on the drill bit. The signal line amplification contact B near the drill bit on the connecting multi-channel negative pressure chip guide drill rod is in contact with the signal line amplification contact A. The auxiliary air supply channel near the drill bit on the connecting multi-channel negative pressure chip guide drill rod is connected to the outside.

[0012] Furthermore, the multi-channel negative pressure chip guide drill rod and the tail multi-channel negative pressure chip guide drill rod have two auxiliary air supply channels and one signal transmission channel. The two auxiliary air supply channels and one signal transmission channel are respectively set on the three edges of the multi-channel negative pressure chip guide drill rod and the tail multi-channel negative pressure chip guide drill rod.

[0013] Furthermore, one end of the tail multi-channel negative pressure chip guide drill rod is connected to the connecting multi-channel negative pressure chip guide drill rod, and the other end of the tail multi-channel negative pressure chip guide drill rod is connected to the negative pressure pipeline through the pneumatic-electric combined slip ring; the auxiliary air supply channel end of the tail multi-channel negative pressure chip guide drill rod near the pneumatic-electric combined slip ring has a flared structure.

[0014] Furthermore, the pneumatic-electric combined slip ring includes a rotating sleeve and a fixed ring. One end of the rotating sleeve is connected to one end of the tail-end multi-channel negative pressure chip guide drill rod, and the other end of the rotating sleeve is rotatably connected to the fixed ring. The end of the fixed ring away from the rotating sleeve is connected to the negative pressure pipeline. A signal line amplification contact C is provided at the end of the rotating sleeve near the tail-end multi-channel negative pressure chip guide drill rod. An energized ring is sleeved on the outer side of the end of the rotating sleeve near the fixed ring. One end of the energized ring is electrically connected to the signal line amplification contact C, and the outer side of the energized ring is electrically connected to the temperature measurement signal output line provided on the fixed ring. When the rotating sleeve rotates, the fixed ring rotates with the rotating sleeve, and the outer wall of the fixed ring remains electrically connected to the temperature measurement signal output line. When the rotating sleeve is connected to the tail-end multi-channel negative pressure chip guide drill rod, the signal line amplification contact B of the tail-end multi-channel negative pressure chip guide drill rod near the pneumatic-electric combined slip ring comes into contact with the signal line amplification contact C.

[0015] A method for using a drill string with negative pressure for transporting drill cuttings includes the following steps:

[0016] S1. Before drilling the cuttings hole, connect the drill bit, the first multi-channel negative pressure cuttings guide drill rod, the tail multi-channel negative pressure cuttings guide drill rod, the pneumatic-electric combination slip ring and the negative pressure pipeline in sequence with threads to ensure that all components are tightly connected before starting the drilling operation.

[0017] S2. The drill bit begins cutting the coal body at the predetermined position. The auxiliary cutting tooth A, in conjunction with the main cutting tooth, cuts the coal body first. Some of the cut drill chips enter the auxiliary chip removal hole under the action of negative pressure. Then, the positive spiral cutting tooth, auxiliary cutting tooth B, and negative spiral cutting tooth begin to cut the deformed coal body. The drill chips move towards the main chip removal hole. Under the action of negative pressure and auxiliary cutting tooth B, the nearby drill chips are sucked into the main chip removal hole. After passing through the installation opening, the through hole, and the rotating sleeve, the drill chips enter the negative pressure pipeline for drill chip separation and collection. While the drill bit is cutting the coal body, the temperature sensor monitors the temperature of the drill chips in real time and transmits the electrical signal through the signal line. As the drill bit continues to cut the coal body, the drilling operation of the first drill rod is gradually completed.

[0018] S3. After the first drill rod is finished drilling, disconnect the first multi-channel negative pressure chip guide drill rod from the tail multi-channel negative pressure chip guide drill rod, and connect the second multi-channel negative pressure chip guide drill rod to continue drilling until the drilling depth reaches the design requirements.

[0019] S4. After the drill cuttings measurement is completed, the negative pressure pipeline, the gas-electric combination slip ring, the tail multi-channel negative pressure cuttings guide drill rod, several connecting multi-channel negative pressure cuttings guide drill rods, and the drill bit can be disassembled in sequence.

[0020] Compared with the prior art, the advantages and positive effects of this invention are:

[0021] 1) This invention can distinguish between the amount of drill cuttings generated by the drill rod cutting the hole wall and the amount of drill cuttings generated by the drill bit cutting the coal body, thus ensuring the accuracy of drill cuttings collection;

[0022] 2) This invention changes the transport channel of the measured drill cuttings, which greatly shortens the transport path of the drill cuttings, and at the same time ensures to a large extent that the original particle size of the drill cuttings is not destroyed after the drill bit cuts the coal body, thus improving the accuracy of the impact results from the perspective of particle size analysis.

[0023] 3) This invention can perform temperature measurement at the original location where drill cuttings are generated, which can accurately reflect the temperature of the drill cuttings and improve the accuracy of rockburst prediction;

[0024] 4) Due to the advantages of its structure, the present invention can directly remove drill cuttings and other materials in the borehole through the internal channel, avoiding the phenomena of "drill jamming" and "drill suction" during the drilling process, and improving drilling efficiency.

[0025] 5) After the drill bit initially cuts into a borehole, the coal body will produce a certain amount of deformation. The drill bit in this invention is divided into three layers of cutting teeth, which can effectively cut off the generated deformation and collect it through negative pressure. This allows for more accurate drill cuttings collection and thus more precise prediction of the risk of rockburst. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a schematic diagram of the structure of the present invention;

[0028] Figure 2 Schematic diagram of drill bit structure Figure 1 ;

[0029] Figure 3 Schematic diagram of drill bit structure Figure 2 ;

[0030] Figure 4 for Figure 3 A schematic diagram of the structure at position A in the middle;

[0031] Figure 5 A schematic diagram of the structure for connecting a multi-channel negative pressure chip guide drill rod;

[0032] Figure 6 for Figure 5 Schematic diagram of the structure at position B in the middle;

[0033] Figure 7 A schematic diagram of the end structure of the multi-channel negative pressure chip guide drill rod at the tail.

[0034] Figure 8 This is a schematic diagram of the structure of a gas-electric combined slip ring. Implementation

[0035] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, any modifications, equivalent substitutions, improvements, etc., made by those skilled in the art to all other embodiments obtained without creative effort should be included within the protection scope of the present invention.

[0036] like Figures 1 to 8 As shown in the figure, this embodiment discloses a drill bit for negative pressure transport of drill cuttings, including a drill bit 1, a multi-channel negative pressure cutting guide drill rod, and a pneumatic-electric combined slip ring 2. The multi-channel negative pressure cutting guide drill rod is divided into two types: a connecting multi-channel negative pressure cutting guide drill rod 3 and a tail multi-channel negative pressure cutting guide drill rod 4. The drill bit 1 and the tail multi-channel negative pressure cutting guide drill rod 4 are connected through the connecting multi-channel negative pressure cutting guide drill rod 3. The pneumatic-electric combined slip ring 2 is connected to the other end of the tail multi-channel negative pressure cutting guide drill rod 4. The connections between the drill bit 1, the multi-channel negative pressure cutting guide drill rod, and the pneumatic-electric combined slip ring 2 are all threaded connections. The drill bit 1, the multi-channel negative pressure cutting guide drill rod, and the pneumatic-electric combined slip ring 2 are all located on the same central axis.

[0037] The drill bit 1 has a cylindrical body 5 as its main body. The top of the cylinder 5 has a chamfered end, and the bottom of the cylinder 5 has an installation opening 6. At the center of the top of the cylinder 5 is a protruding hemispherical 31, with an auxiliary cutting tooth A7 on its top. Three-wing blades 8 are evenly distributed radially along the top and sides of the cylinder 5. Each blade 8 has four layers of cutting teeth: the first layer is the main cutting tooth 9, the second layer is a positive helical cutting tooth 10, the third layer is an auxiliary cutting tooth B32, and the fourth layer is a negative helical cutting tooth 11. A main chip removal hole 12 is distributed between two adjacent auxiliary cutting teeth B32. The three-wing blades 8 are distributed with… There are three main chip removal holes 12. The auxiliary cutting tooth A7 has a certain angle with the top of the cylinder 5. An auxiliary chip removal hole 13 is provided on the protruding hemispherical 31 at the bottom of the auxiliary cutting tooth A7. The opening direction of the auxiliary chip removal hole 13 is consistent with the orientation of the auxiliary cutting tooth A7, and both are located between two blades 8. The auxiliary chip removal hole 13 and the main chip removal holes 12 are connected to the mounting opening 6 at the bottom of the cylinder 5. Temperature sensors 14 are distributed on one blade 8 with the opening direction opposite to that of the auxiliary chip removal hole 13. The temperature measurement signal line 15 of the temperature sensor 14 is embedded in the root of the blade 8 and transmitted to the end of the blade 8, forming a signal line amplification contact A16 at the end of the blade 8. An external thread A17 is provided at the bottom of the cylinder 5 and is coaxial with the mounting opening 6.

[0038] The main cutting teeth are primarily used to cut the original coal body within the diameter of the drill cutting hole. The auxiliary cutting teeth A are used to cut the small circular coal column formed at the center of the bottom of the hole after the main cutting teeth have cut the coal body. This is to prevent the generation of large-diameter drill cuttings at the center of the bottom of the hole, which would affect the movement of the drill cuttings. The second layer of positive spiral cutting teeth, the third layer of auxiliary cutting teeth B, and the fourth layer of negative spiral cutting teeth are mainly used to cut the hole wall deformation that occurs after the main cutting teeth have initially formed the hole, further ensuring the accurate collection of drill cuttings.

[0039] The main cutting tooth on the blade consists of three cutting teeth. Two of the larger diameter cutting teeth are horizontally arranged side by side and vertically fixed to the top of the blade, mainly used for cutting the bottom of the drill cutting hole. The other smaller cutting tooth is fixed side by side to the bottom of the outer cutting tooth on the top of the blade. The smaller cutting tooth has the same diameter as the cutting teeth on the positive helical cutting tooth, auxiliary cutting tooth B, and anti-helical cutting tooth, and also has the same function.

[0040] The multi-channel negative pressure chip guide drill rod is divided into two types: the connecting multi-channel negative pressure chip guide drill rod 3 and the tail multi-channel negative pressure chip guide drill rod 4. The connecting multi-channel negative pressure chip guide drill rod 3 is approximately triangular in shape, and has a through hole 18 along the axial direction of the connecting multi-channel negative pressure chip guide drill rod 3. The diameter of the through hole 18 is the same as the diameter of the mounting opening 6 at the bottom of the drill bit, and both are negative pressure channels for the drill chips. One end of the connecting multi-channel negative pressure chip guide drill rod 3 is provided with an internal thread A19 connection end, and the other end is provided with an external thread. At the B20 connection end, a small-diameter circular through hole is distributed along the three edges of the drill rod around the through hole 18. Two of the circular through holes are used to supply air to the auxiliary chip removal hole 13 and the main chip removal hole 12, and are called auxiliary air supply channels 21. The other circular through hole serves as the channel for the temperature measurement signal line 15 and is called signal transmission channel 22. Signal line amplification contacts B23 are arranged at both ends of the signal transmission channel 22. Shallow positive spiral grooves are provided on the three edges of the drill rod.

[0041] The difference between the tail multi-channel negative pressure chip guide drill rod 4 and the connecting multi-channel negative pressure chip guide drill rod 3 is that the tail multi-channel negative pressure chip guide drill rod 4 is shorter in length, and its external thread B20 end is used to connect the pneumatic-electric combination slip ring 2. The inlet of the auxiliary air supply channel 21 at the external thread B20 end forms an enlarged diameter inlet 28 in the radial direction of the drill rod, which facilitates the entry of external gas.

[0042] The pneumatic-electric combined slip ring includes a rotating sleeve 29 and a fixed ring 30. One end of the rotating sleeve 29 is provided with an internal thread B27, which is connected to the external thread B20 end of the tail multi-channel negative pressure chip guide drill rod 4. After the connection is tight, a signal line amplification contact C24 is arranged at the contact position between the rotating sleeve 29 and the signal line amplification contact B23 of the tail multi-channel negative pressure chip guide drill rod 4. The end of the rotating sleeve 29 away from the tail multi-channel negative pressure chip guide drill rod 4 is rotatably connected to the fixed ring 30. A flange interface 25 is provided at the end away from the rotating sleeve 29 for connecting to the negative pressure pipeline. An energized ring is sleeved on the outer side of the end of the rotating sleeve 29 near the fixed ring 30. One end of the energized ring is electrically connected to the signal line amplification contact C24, and the outer side of the energized ring is electrically connected to the temperature measurement signal output line 26 provided on the fixed ring 30. When the rotating sleeve 29 rotates, the fixed ring 30 rotates with the rotating sleeve 29, and the outer wall of the fixed ring 30 remains electrically connected to the temperature measurement signal output line 26.

[0043] The function of the gas-electric combined slip ring 2 is to convert the rotating electrical signal and the negative pressure gas with drill cuttings into a fixed electrical signal and the negative pressure gas with drill cuttings, so as to facilitate the subsequent processing of the electrical signal and the negative pressure gas with drill cuttings.

[0044] During the cuttings removal process, the positive helical cutting teeth 10 cause the cuttings to move toward the main cuttings removal hole 12, and the negative helical cutting teeth 11 also cause the cuttings to move toward the main cuttings removal hole 12, eventually causing the cuttings to accumulate at the main cuttings removal hole 12. Under negative pressure, the main cuttings removal hole 12 draws the nearby cuttings into the mounting opening 6 and the through hole 18 at the bottom of the drill bit, while the auxiliary cuttings removal hole 13 also draws the nearby cuttings into it.

[0045] When drilling cuttings method encounters special circumstances, such as high coal stress, borehole collapse in the middle or a large amount of drill cuttings, and the gas passing through the gap between the drill rod and the borehole wall cannot meet the gas requirements for negative pressure slag discharge, the two auxiliary air supply channels 21 can continue to provide gas for negative pressure slag discharge.

[0046] After the drill bit is tightly connected, the signal line amplification contact A16, signal line amplification contact B23, and signal line amplification contact C24 will be in close contact.

[0047] This embodiment also discloses a method for using a drill bit to move drill cuttings under negative pressure, including the following steps:

[0048] Step 1: Before drilling, connect the drill bit 1, the first multi-channel negative pressure chip guide drill rod 3, the tail multi-channel negative pressure chip guide drill rod 4, the pneumatic-electric combination slip ring 2, and the negative pressure pipeline in sequence to make each component tightly connected before starting the drilling.

[0049] Step 2: Drill bit 1 begins cutting the coal body at the predetermined position. Auxiliary cutting tooth A7, in conjunction with main cutting tooth 9, first cuts the coal body. Some of the cut drill chips enter the auxiliary chip removal hole 13 under negative pressure. Then, the second layer of positive spiral cutting teeth 10, the third layer of auxiliary cutting teeth B32, and the fourth layer of anti-spiral cutting teeth 11 begin to cut the deformed coal body. The drill chips move towards the main chip removal hole 12. Under the action of negative pressure and auxiliary cutting tooth B32, nearby drill chips are sucked into the main chip removal hole 12. The drill chips pass through the installation opening 6 of the drill bit, the through hole 18, and the gas-electric combination slip ring 2, and then enter the negative pressure pipeline for drill chip separation and collection. While the drill bit 1 is cutting the coal body, the temperature sensor 14 monitors the temperature of the drill chips in real time and transmits the electrical signal through the signal line and signal transmission channel 22. As the drill bit continues to cut the coal body, the drilling of the first drill rod is gradually completed.

[0050] Step 3: After the first drill rod is completed, disconnect the first multi-channel negative pressure chip guide drill rod 3 from the tail multi-channel negative pressure chip guide drill rod 4, and connect the second multi-channel negative pressure chip guide drill rod 3 to continue the construction of the chip hole until the depth of the chip hole reaches the design requirements. As the drilling depth increases, the external positive spiral groove of the multi-channel negative pressure chip guide drill rod 3 will cut the hole wall to a certain extent. The resulting drill chips will be guided out of the hole through the gap between the drill rod and the hole wall by the positive spiral groove on the outer surface of the drill rod, without affecting the required measurement of the amount of drill chips, thus ensuring the accuracy of the drill chip measurement.

[0051] Step 4: After the drill cuttings measurement is completed, disassemble the negative pressure pipeline, the gas-electric combination slip ring 2, the tail multi-channel negative pressure cuttings guide drill rod 4, several connecting multi-channel negative pressure cuttings guide drill rods 3 and drill bit 1 in sequence.

[0052] The present invention has the following beneficial effects:

[0053] 1) This invention can distinguish between the amount of drill cuttings generated by the drill rod cutting the hole wall and the amount of drill cuttings generated by the drill bit cutting the coal body, thus ensuring the accuracy of drill cuttings collection;

[0054] 2) This invention changes the transport channel of the measured drill cuttings, which greatly shortens the transport path of the drill cuttings, and at the same time ensures to a large extent that the original particle size of the drill cuttings is not destroyed after the drill bit cuts the coal body, thus improving the accuracy of the impact results from the perspective of particle size analysis.

[0055] 3) This invention can perform temperature measurement at the original location where drill cuttings are generated, which can accurately reflect the temperature of the drill cuttings and improve the accuracy of rockburst prediction;

[0056] 4) Due to the advantages of its structure, the present invention can directly remove drill cuttings and other materials in the borehole through the internal channel, avoiding the phenomena of "drill jamming" and "drill suction" during the drilling process, and improving drilling efficiency.

[0057] 5) After the drill bit initially cuts into a borehole, the coal body will produce a certain amount of deformation. The drill bit in this invention is divided into three layers of cutting teeth, which can effectively cut off the generated deformation and collect it through negative pressure. This allows for more accurate drill cuttings collection and thus more precise prediction of the risk of rockburst.

Claims

1. A drilling tool for negative pressure transport of drill cuttings, comprising a drill bit and a drill rod, wherein the drill bit is connected to one end of the drill rod, and the other end of the drill rod is connected to a negative pressure pipeline; characterized in that: The drill bit is cylindrical, with a hollow cavity inside. The bottom of the hollow cavity is connected to an installation opening at the bottom of the drill bit. Several blades are arranged along the circumference of the drill bit's sidewall. Each blade has a main cutting tooth at its tip, a positive helical cutting tooth at the top center, an auxiliary cutting tooth B at the bottom center, and a negative helical cutting tooth at the bottom. A main chip removal hole is located between adjacent auxiliary cutting teeth B. A protruding hemispherical shape is located at the center of the drill bit's tip, with an auxiliary cutting tooth A at its tip. Auxiliary cutting tooth A is inclined, and an auxiliary chip removal hole is located at its bottom, with the axis of the auxiliary chip removal hole aligned with the inclination direction of the auxiliary cutting tooth A. Both the main and auxiliary chip removal holes are connected to the hollow cavity inside the drill bit. The drill bit is connected to the drill rod through the installation opening. The drill pipe includes a tail-end multi-channel negative pressure chip guide drill pipe; there is one tail-end multi-channel negative pressure chip guide drill pipe; The drill pipe also includes a multi-channel negative pressure chip guide drill pipe, which is disposed between the drill bit and the tail multi-channel negative pressure chip guide drill pipe. There are several multi-channel negative pressure chip guide drill pipes connected end to end. One end of the multi-channel negative pressure chip guide drill pipe after the end is connected to the drill bit, and the other end of the multi-channel negative pressure chip guide drill pipe after the end is connected to the tail multi-channel negative pressure chip guide drill pipe. Both the connecting multi-channel negative pressure chip guide drill rod and the tail multi-channel negative pressure chip guide drill rod are triangular prisms, with positive spiral grooves on each of their three edges. A through hole is located at the center of both the connecting and tail multi-channel negative pressure chip guide drill rods, with the axis of the through hole aligned with the axis of the connecting multi-channel negative pressure chip guide drill rod. An auxiliary air supply channel and a signal transmission channel are located outside the through hole, both penetrating the connecting and tail multi-channel negative pressure chip guide drill rods. The length of the connecting and tail multi-channel negative pressure chip guide drill rods is [not specified]. Signal line amplification contacts B are provided at both ends of the signal transmission channel, and signal line amplification contacts B are located at both ends of the signal transmission channel. Signal lines are provided in the signal transmission channel, and the two ends of the signal lines are respectively connected to the signal line amplification contacts B located at both ends of the signal transmission channel. When the connecting multi-channel negative pressure chip guide drill rod and the tail multi-channel negative pressure chip guide drill rod are connected to the drill bit, the through holes and auxiliary air supply channels between the tail multi-channel negative pressure chip guide drill rod and the connecting multi-channel negative pressure chip guide drill rod, and between adjacent connecting multi-channel negative pressure chip guide drill rods are connected. The signal line amplification contacts B between the tail multi-channel negative pressure chip guide drill rod and the connecting multi-channel negative pressure chip guide drill rod, and between adjacent connecting multi-channel negative pressure chip guide drill rods, are in contact with each other.

2. The drill bit for negative pressure transport of drill cuttings as described in claim 1, characterized in that: A temperature sensor is provided on one side of the blade tip, and the temperature sensor is electrically connected to the signal line amplification contact A located at the bottom of the blade; the through hole on the multi-channel negative pressure chip guide drill rod is connected to the mounting opening on the drill bit; the signal line amplification contact B near the drill bit on the multi-channel negative pressure chip guide drill rod is in contact with the signal line amplification contact A; and the auxiliary air supply channel near the drill bit on the multi-channel negative pressure chip guide drill rod is connected to the outside.

3. The drill bit for negative pressure transport of drill cuttings as described in claim 2, characterized in that: The multi-channel negative pressure chip guide drill rod and the tail multi-channel negative pressure chip guide drill rod have two auxiliary air supply channels and one signal transmission channel. The two auxiliary air supply channels and one signal transmission channel are respectively set on the three edges of the multi-channel negative pressure chip guide drill rod and the tail multi-channel negative pressure chip guide drill rod.

4. The drill bit for negative pressure transport of drill cuttings as described in claim 3, characterized in that: One end of the tail multi-channel negative pressure chip guide drill rod is connected to the connecting multi-channel negative pressure chip guide drill rod, and the other end of the tail multi-channel negative pressure chip guide drill rod is connected to the negative pressure pipeline through the pneumatic-electric combined slip ring; the auxiliary air supply channel end of the tail multi-channel negative pressure chip guide drill rod near the pneumatic-electric combined slip ring has a flared structure.

5. The drill bit for negative pressure transport of drill cuttings as described in claim 4, characterized in that: The pneumatic-electric combined slip ring includes a rotating sleeve and a fixed ring. One end of the rotating sleeve is connected to one end of the tail-end multi-channel negative pressure chip guide drill rod, and the other end of the rotating sleeve is rotatably connected to the fixed ring. The end of the fixed ring away from the rotating sleeve is connected to the negative pressure pipeline. A signal line amplification contact C is provided at the end of the rotating sleeve near the tail-end multi-channel negative pressure chip guide drill rod. An energized ring is sleeved on the outer side of the end of the rotating sleeve near the fixed ring. One end of the energized ring is electrically connected to the signal line amplification contact C, and the outer side of the energized ring is electrically connected to the temperature measurement signal output line provided on the fixed ring. When the rotating sleeve rotates, the fixed ring rotates with the rotating sleeve, and the outer wall of the fixed ring remains electrically connected to the temperature measurement signal output line. When the rotating sleeve is connected to the tail-end multi-channel negative pressure chip guide drill rod, the signal line amplification contact B of the tail-end multi-channel negative pressure chip guide drill rod near the pneumatic-electric combined slip ring comes into contact with the signal line amplification contact C.

6. A method of using a drill bit for negative pressure transport of drill cuttings as described in claim 5, characterized in that: Includes the following steps: S1. Before drilling the cuttings hole, connect the drill bit, the first multi-channel negative pressure cuttings guide drill rod, the tail multi-channel negative pressure cuttings guide drill rod, the pneumatic-electric combination slip ring and the negative pressure pipeline in sequence with threads to ensure that all components are tightly connected before starting the drilling operation. S2. The drill bit begins cutting the coal body at the predetermined position. The auxiliary cutting tooth A, in conjunction with the main cutting tooth, cuts the coal body first. Some of the cut drill chips enter the auxiliary chip removal hole under the action of negative pressure. Then, the positive spiral cutting tooth, auxiliary cutting tooth B, and negative spiral cutting tooth begin to cut the deformed coal body. The drill chips move towards the main chip removal hole. Under the action of negative pressure and auxiliary cutting tooth B, the nearby drill chips are sucked into the main chip removal hole. After passing through the installation opening, the through hole, and the rotating sleeve, the drill chips enter the negative pressure pipeline for drill chip separation and collection. While the drill bit is cutting the coal body, the temperature sensor monitors the temperature of the drill chips in real time and transmits the electrical signal through the signal line. As the drill bit continues to cut the coal body, the drilling operation of the first connecting multi-channel negative pressure chip guide drill rod is gradually completed. S3. After the first multi-channel negative pressure chip guide drill rod is completed, disconnect the first multi-channel negative pressure chip guide drill rod from the tail multi-channel negative pressure chip guide drill rod, and connect the second multi-channel negative pressure chip guide drill rod to continue drilling until the drilling depth reaches the design requirements. S4. After the drill cuttings measurement is completed, the negative pressure pipeline, the gas-electric combination slip ring, the tail multi-channel negative pressure cuttings guide drill rod, several connecting multi-channel negative pressure cuttings guide drill rods, and the drill bit can be disassembled in sequence.

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