CN111594134B - An intelligent drill bit for real-time monitoring of drilling cutting force and its working method - Google Patents

Abstract

The invention discloses an intelligent drill bit for real-time monitoring of drilling cutting force and a working method thereof, comprising a PDC drill bit body, a plurality of uniformly distributed PDC drill bit blades on the drill bit body, and belts on the cutting surface of the PDC bit blade blades There are installation holes, and a plurality of PDC drill cutting teeth are arranged in the installation holes. In each row of PDC drill cutting teeth, there is at least one pressure measuring cutting tooth; The middle part of the blade is provided with a through hole, which is used as a wiring groove. The lower part of the wiring groove is connected to the hollow cavity inside the nozzle, and the upper part is connected to the monitoring device of the pressure measuring cutting teeth; the wiring groove is provided with a wire and a signal conversion module, the wire The monitoring device is connected to the signal conversion module, and the signal conversion module is provided with a wireless signal transmitting device. By adding a monitoring device while drilling, the present invention can significantly improve the PDC bit's perception of formation rock characteristics, and provide strong technical support for directional drilling technology and sweet spot identification.

Description

An intelligent drill bit for real-time monitoring of drilling cutting force and its working method

technical field

The invention relates to the technical field of drilling tools, in particular to an intelligent drill bit, in particular to an intelligent drill bit for real-time monitoring of drilling cutting force and a working method thereof.

Background technique

Drill bits are an essential tool in drilling engineering, used for geological exploration, oil and gas exploitation, water well drilling, etc. For different formations, drill bits with different structures and functions need to be selected. In the oil industry, with the increasing demand for unconventional oil and gas resources, the corresponding drilling technology and equipment are also gradually developing, among which the main function of the drill bit is to break the rock and form a wellbore. At present, drill bits can be divided into three types: diamond bits, roller cone bits and scraper bits. In addition, there are some new drill bits developed on the basis of these three bits.

PDC drill bit is a new type of cutting drill bit made of synthetic polycrystalline diamond cutting blocks embedded in the drill bit matrix. In recent years, with the change of mixing process and manufacturing process, the erosion resistance and impact resistance of PDC bits have been greatly improved. At the same time, the PDC bit has also achieved major breakthroughs in tooth design technology and tooth arrangement. Therefore, the application of PDC bits is becoming more and more extensive.

Cutting force is an important physical quantity in the process of PDC drill bit breaking rock, but the existing technology cannot measure the cutting force. At the same time, the existing test-while-drilling tools cannot provide the front-end information of the PDC bit when the rock is broken, and there is a certain lag in the identification of reservoir lithology.

In response to the above problems, there are now some related exploration solutions, such as the Chinese patent with the application number of 201621181006.4, which provides a way to monitor the cutting torque in real time, but it is a thrust signal detected by a torque sensor. The accuracy is limited. The Chinese patent with the application number of 201810360236.4 discloses a device that can collect downhole mechanical parameters, but does not disclose how to collect it, nor whether it can collect cutting force.

SUMMARY OF THE INVENTION

In view of the above problems, the present invention provides an intelligent drill bit for real-time monitoring of drilling cutting force. By adding a monitoring device while drilling, the perception of formation rock characteristics by the PDC bit can be significantly improved, providing strong technical support for directional drilling technology and sweet spot identification.

The technical scheme of the present invention is as follows:

An intelligent drill bit for real-time monitoring of drilling cutting force, comprising a PDC drill bit body, a plurality of PDC drill bit blades evenly distributed on the drill bit body, and a plurality of PDC drill bit cutting teeth on the cutting surface of the PDC bit blade blade, It is characterized in that, in each row of PDC drill bit cutting teeth, at least one pressure measuring cutting tooth is included; the pressure measuring cutting tooth is provided with a pressure monitoring device, and the middle part of the PDC drill bit blade is provided with an internal wiring groove of the blade, and the There is a wiring groove on the gauge surface of the PDC drill bit, the lower part of the wiring groove on the gauge surface is connected to the hollow cavity inside the nozzle, and the upper part is connected to the pressure monitoring device of the pressure measuring cutting teeth; the wiring groove inside the blade is provided with The wire is provided with a signal conversion module in the wiring groove of the gauge surface, the wire is connected from the pressure monitoring device to the signal conversion module, and the signal conversion module is provided with a wireless signal transmitting device.

Further, the pressure monitoring device is a piezoelectric sensor, and the piezoelectric sensor is nested in the middle of the cutting teeth of the PDC drill that is processed into a hollow structure to form a pressure measuring cutting tooth, and the surface of the wire connected to the piezoelectric sensor is coated with high temperature resistant. insulating paint.

Further, the piezoelectric sensor includes a base, the base is a hollow cylinder structure, one end of which is provided with a circular hole with an opening in the middle, the aperture is smaller than the inner diameter of the cylinder, and the outer wall of the other end is provided with a section of flange, There are a plurality of threaded holes in the flange, the end sensor top cover on the side of the base with the threaded holes, the sensor top cover is provided with a plurality of threaded holes corresponding to the base, and through the matching studs The sensor top cover is provided with a pressure plate, a first piezoelectric crystal, a conductive sheet, and a second piezoelectric crystal in sequence, and they are pressed into the base through the sensor top cover, so that the second piezoelectric crystal at the end is pressed. The outer edge of the crystal blocks the circular hole in the base;

There is also a section of wire socket above the sensor top cover, the wire socket is also provided with threaded holes, and is fixed on the sensor top cover and the base through studs.

A wire is connected to the side of the conductive sheet, a hole is provided on the sensor top cover, and the wire extends from the inside of the base through the hole on the sensor top cover to the outside and is finally connected to the signal conversion module;

The diameter of the piezoelectric sensor is 8 mm, which is smaller than the diameter of the cutting teeth of the PDC drill.

Further, the PDC drill bit cutter for placing the piezoelectric sensor is processed into a cylindrical structure with one end closed, a circular boss is provided inside the closed end, and the diameter and depth of the circular boss are the same as those set on the base. The size of the circular hole at one end of the seat is exactly the same, and the circular boss can just contact the second piezoelectric crystal near the end. There are a plurality of threaded holes at the other end of the PDC drill cutting gear cylinder structure, and the end of the threaded holes is There is a pressing plate, and there are threaded holes corresponding to the cylinder structure of the PDC drill bit on the pressing plate. The pressing plate and the PDC bit cutting teeth are fixed by bolts, and the piezoelectric sensor PDC bit cutting teeth are further fixed. internal.

Further, the lower part of the wiring groove is connected to the side of the hollow cavity inside the PDC drill body, and is connected from the hollow cavity to the outside of the PDC drill body, a counterbore is provided on the outside of the connection, and a signal conversion module is placed in the counterbore, and A wireless signal transmitting device is arranged in the wiring groove between the signal conversion module and the hollow cavity inside the PDC drill body.

Further, the internal wiring groove of the blade and the wiring groove of the gauge surface have an L-shaped structure, the top of which extends vertically from below the piezoelectric sensor to above the hollow cavity inside the PDC drill body, and then extends horizontally to the side of the PDC drill blade. It is used as the internal wiring groove of the blade, and then a whole piece of empty groove is set down from the blade of the PDC drill to serve as the wiring groove of the gauge surface. The wiring groove of the gauge surface is connected to the counterbore to form an inverted T-shaped structure with the counterbore.

Further, a T-shaped sealing block is provided outside the wiring groove of the gauge surface and the counterbore. The sealing block is hard rubber and is pressed against the inverted T-shaped structure formed by the wiring groove and the counterbore of the gauge surface. , keep the inside and outside sealed.

Further, the pressure measuring cutting teeth are modified from the PDC drill cutting teeth arranged in the middle of the blade. If the number of PDC drilling cutting teeth on the blade is an even number, 2 PDC drilling cutting teeth in the middle are selected. The PDC bit cutters in the PDC bit close to the axis of the PDC bit body are retrofitted.

Further, there are matching wireless signal receivers, data acquisition cards and computers in the well site.

A working method of an intelligent drill bit for real-time monitoring of drilling cutting force, the steps are as follows:

When the drill bit is working, the PDC bit cutter on the PDC bit blade cuts the formation. At this time, the cutting force is measured by the piezoelectric sensor on the pressure measuring cutter, and the electrical signal is transmitted to the signal conversion module through the wire. The electrical signal undergoes charge amplification and voltage amplification in the signal conversion module, and the amplifier outputs a voltage that meets the requirements, and then is filtered by a low-pass filter and becomes a low-frequency voltage signal. The low-frequency voltage signal is sampled by the sample-hold circuit in the sample-hold circuit unit. After holding, it becomes a discrete signal, and the discrete signal becomes a digital signal after A/D conversion. The processed digital signal is sent to the ground through a wireless signal transmitting device, and the signal is received through a wireless signal receiving device and transmitted to a computer through a data acquisition card. , the collected electrical signal is recorded and saved by the computer; and/or after the processed digital signal is sent to the wireless signal transmitting device, it is stored in the wireless signal transmitting device, and the internal data is analyzed after being taken out.

The benefits of the present invention are:

Compared with the prior art, the present invention has the following beneficial effects:

By improving the structure and installing the monitoring device, the present invention can accurately collect the cutting force generated when the PDC drill bit breaks the rock, and the collected data can be fed back to the well in real time, which is convenient for the construction personnel to adjust and control the working state of the drill bit according to the real-time data. To a certain extent, it solves the problem of lag in the acquisition of reservoir lithology data at the front end of the PDC bit by existing MWD tools. At the same time, its structure has no effect on the performance of the drill bit itself, as well as the erosion resistance and impact resistance;

In terms of structure, the present invention relates to the method of combining piezoelectric sensors in layers, and improves the cutting teeth of PDC bit, so that it has better sealing and contact performance, and ensures accurate monitoring results. At the same time, the structure itself is solid and durable. It can be used for no less than 1,000 hours in the downhole, effectively improving the cutting pressure monitoring capability, providing guidance for the construction parameters such as the rotational speed on the well, and also providing a data acquisition plan for the arrangement of the same type of drilling work.

Description of drawings

Fig. 1 is the structural representation of a kind of intelligent drill bit for real-time monitoring of cutting force in oil and gas drilling of the present invention;

Fig. 2a is the axial view of the assembly drawing of the piezoelectric sensor installed on the drill bit body;

Figure 2b is a right side view of Figure 2a;

Fig. 2c is the A-A sectional view of Fig. 2a;

Fig. 3a is the design structure diagram of piezoelectric sensor;

Figure 3b is a right side view of Figure 3a;

Fig. 3c is the B-B sectional view of Fig. 3a;

Figure 4a is an assembly diagram of the piezoelectric sensor mounted on the PDC composite sheet;

Figure 4b is a right side view of Figure 4a;

Fig. 4c is the C-C sectional view of Fig. 4a;

FIG. 5 is a flow chart of the overall assembly of the piezoelectric sensor.

The meanings of the symbols in the figure are:

1-PDC bit body;

2-PDC drill blade, 21-PDC drill cutter, 22-internal wiring groove of blade, 23-gauge surface wiring groove, 24-pressure measuring cutter, 241-piezoelectric sensor, 2411-wire socket, 2412 - Stud, 2413- Conductor, 2414- Sensor Top Cover, 2415- Pressure Plate, 2416- Piezoelectric Crystal, 2417- Conductive Piece, 2418- Base, 242- Pressure Measuring Cutter End Cover;

3-water eye;

4-Signal conversion module;

5-Wireless signal transmitting device;

6- Bit connector.

Detailed ways

The present invention will be further described below in conjunction with the embodiments. It should be noted that in this paper, words such as "upper" and "lower" are only used to facilitate the description of the accompanying drawings, and do not limit the direction in actual use, and do not necessarily Any such actual relationship or order between these entities or operations is required or implied. Moreover, the terms "comprising", "comprising" or any other variation thereof are intended to encompass non-exclusive inclusion such that a process, method, article or device comprising a list of elements includes not only those elements, but also includes not explicitly listed or other elements inherent to such a process, method, article or apparatus.

As shown in Figure 2, an intelligent drill bit for real-time monitoring of drilling cutting force includes a PDC drill bit body 1, a plurality of uniformly distributed blades 2 are arranged on the bit body, and each blade 2 is provided with a plurality of PDC bit cutting tooth 21, and at least one pressure-measuring cutting tooth 24; the pressure-measuring cutting tooth 24 is provided with a piezoelectric sensor, and a communication hole is provided in the middle of the blade 2 as a wiring groove, and the lower part of the wiring groove is connected to the inner part of the nozzle. The hollow cavity, the upper part is connected to the monitoring device of the pressure measuring cutting teeth 24; the wire and the signal conversion module 4 are arranged in the wiring groove, the wire is connected from the monitoring device to the signal conversion module 4, and the signal conversion module 4 has a wireless signal transmitting device 5. The wireless signal transmitting device 5 has a built-in memory, which can store data, and the storage space can be selected according to needs, not less than 1G. The monitoring device is a piezoelectric sensor 241, and the piezoelectric sensor 241 is a specially customized miniature piezoelectric sensor crystal with a small size to be embedded in the cutting teeth of the PDC drill bit. At the same time, the piezoelectric sensor 241 crystal. The Curie point should be as high as possible to prevent depolarization during processing. The piezoelectric sensor 241 is nested in the middle of the ordinary PDC drill cutting teeth 21 to form the pressure measuring cutting teeth 24 . The diameter of the piezoelectric sensor 241 is 8 mm, which is smaller than the diameter of the cutting teeth 21 of the PDC drill. The lower part of the wiring groove is connected to the side of the hollow cavity inside the PDC drill body 1, and is connected from the hollow cavity to the outside of the PDC drill body 1, and a counterbore is provided on the outside of the connection, and the signal conversion module 4 is placed in the counterbore, and A wireless signal transmitting device is arranged in the wiring groove between the signal conversion module 4 and the hollow cavity inside the PDC bit body 1, and a matching wireless signal receiver, data acquisition card and computer are arranged in the uphole area of the well site. The wiring groove is generally an L structure, the top of which extends vertically from below the piezoelectric sensor 241 to above the hollow cavity inside the PDC drill body 1, and then extends horizontally to the side of the PDC drill blade 2, as the internal wiring groove 22 of the blade, and then From the PDC bit blade 2 downward, a whole piece of empty groove is provided as the gauge surface wiring groove 23, and the gauge surface wiring groove 23 is connected to the counterbore to form an inverted T-shaped structure with the counterbore. The outside of the gauge surface wiring groove 23 and the counterbore is provided with a T-shaped sealing block. The sealing block is hard rubber, such as ZP-375 industrial rubber, and is pressed against the gauge surface wiring groove 23 and the counterbore. In the inverted T-shaped structure composed of holes, the inner and outer seals are maintained to protect the internal electrical components. The inner wiring groove 22 of the blade and the wiring groove 23 on the gauge surface are painted with a layer of zs-411 high temperature resistant paint. The conversion module 4 is sealed with rubber.

Further, the pressure measuring cutting teeth 24 are modified from the PDC drill cutting teeth 21 arranged in the middle of the blade 2. If the PDC drill cutting teeth 21 on the blade 2 are even in number, the middle 2 is selected. Of the PDC drill cutters 21, the PDC drill cutters 21 close to the axis of the PDC drill body 1 are used for modification; of course, other PDC drill cutters 21 provided on them can also achieve the detection effect, but it is most preferable to be close to the middle. , its service life is longer.

Further, the method of converting the PDC drill cutting teeth 21 into pressure measuring cutting teeth 24 is as follows: the PDC drill cutting teeth 21 are cut into a small opening, and in the low temperature environment, the PDC drill cutting teeth 21 shrink when cold, the incision is enlarged, and the pressure is reduced. The electrical sensor 241 is embedded in the incision. At room temperature or downhole temperature, the cutting teeth 21 of the PDC bit expand when heated, and the incision shrinks. The cutting teeth 21 of the PDC bit and the piezoelectric sensor 241 automatically realize interference fit, and the initial compression at this time is realized. The force is cleared in the data as a compensation parameter, so that the pressure on the piezoelectric sensor 241 during cutting is the cutting force generated by the cutting teeth 2 of the PDC drill.

As shown in Figures 3a-3c, when the piezoelectric sensor 241 is assembled, a layer of zs-411 high temperature resistant paint with a thickness of about 0.4 mm needs to be painted on the housing of the piezoelectric sensor 241. The first piezoelectric crystal and the base 2418, the conductive sheet 2417 and the second piezoelectric crystal, and the pressure plate 2415 and the first piezoelectric crystal are connected by conductive glue, and the conductive sheet 2417 and the wire 2413 are connected by thermal pressure welding. The base 2418 and top cover 2414 need to be degreasing and cleaned prior to assembly. The entire housing cavity and the inlet and outlet of the wire 3 are sealed with rubber. As shown in Figures 4a-4c, the sensor base 2418 and the sensor top cover 2414 are also degreasing and cleaned prior to assembly. The inner surface of the cutting teeth is painted with zs-411 high temperature resistant paint. The inlet and outlet of the wire on the end cover 242 of the pressure measuring cutting tooth are sealed with rubber, and the spare part inside the cutting tooth is filled with rubber. Specifically, the piezoelectric sensor 241 includes a base 2418, the base 2418 is a hollow cylindrical structure, one end of which is provided with a circular hole with an opening in the middle, the diameter of which is smaller than the inner diameter of the cylinder, and the outer wall of the other end is provided with There is a flange with a plurality of threaded holes in the flange, the end sensor top cover 2414 on the side of the base 2418 with the threaded holes, the sensor top cover 2414 is provided with a plurality of threads corresponding to the base 2418 The sensor top cover 2414 is provided with a pressure plate 2415, a first piezoelectric crystal, a conductive sheet 2417, and a second piezoelectric crystal in sequence, and they are pressed by the sensor top cover 2414. Tightly inside the base 2418, let the outer edge of the second piezoelectric crystal at the end block the circular hole of the base 2418, a circular counterbore is provided on the inside of the sensor top cover 2414, and a circular column is provided on the top of the pressure plate 2415 , the circular column is just snapped into the circular countersunk hole and fixed; there is also a section of wire socket 2411 above the sensor top cover 2414, the wire socket 2411 is also provided with threaded holes, and is fixed on the sensor top cover 2414 and the base through the stud 2412 On the seat 2418, in particular, as shown in FIG. 3a, the wire socket 2411 is in the shape of a strip, and its length is only half of the sensor top cover 2414, one end is fixed by the bolt 2412, and the other end extends to the position of the axis of the sensor top cover 2414, to plug in. A wire 2413 is connected to the side of the conductive sheet 2417, and a hole is provided on the sensor top cover 2414. The wire 2413 extends from the inside of the base 2418 through the hole on the sensor top cover 2414 to the outside and is finally connected to the signal conversion module 4; the The diameter of the piezoelectric sensor 241 is 8 mm, which is smaller than the diameter of the cutting teeth 21 of the PDC drill. The PDC drill cutter 21 for placing the piezoelectric sensor 241 is processed into a cylindrical structure with one end closed, a circular boss is arranged inside the closed end, and the diameter and depth of the circular boss are the same as those set on the base. The size of the circular hole at one end of 2418 is exactly the same, and the circular boss can just touch the second piezoelectric crystal near the end. There are multiple threaded holes on the other end of the barrel structure of the PDC drill cutting tooth 21, and the threaded holes The end is provided with a pressing plate, and the pressing plate is provided with threaded holes corresponding to the cylindrical structure of the PDC drill cutting teeth 21. The pressing plate and the PDC drill cutting teeth 21 are fixed by bolts 2412, and the piezoelectric sensor is further connected. 241 is compressed inside the cutting teeth 21 of the PDC bit.

A kind of intelligent drill bit for real-time monitoring of drilling cutting force adopting the above structure, and its use method is as follows:

When the drill bit is working, the PDC bit cutter 21 on the PDC bit blade 2 cuts the formation. At this time, the cutting force is measured by the piezoelectric sensor 241 on the pressure-measuring cutter 24, and the electrical signal is transmitted to the ground via the wire 2413. The signal conversion module 4 performs charge amplification and voltage amplification on the electrical signal in the signal conversion module 4, and the amplifier outputs a voltage that meets the requirements, and then is filtered by a low-pass filter to become a low-frequency voltage signal, and the low-frequency voltage signal passes through the sampling and holding circuit. After the sampling and holding of the sampling and holding circuit in the unit, it becomes a discrete signal, and the discrete signal is converted into a digital signal after A/D conversion. The processed digital signal is sent to the ground through the wireless signal transmitting device 5, and the signal is received through the wireless signal receiving device. And it is transmitted to the computer via the data acquisition card, the computer records and saves the collected electrical signals, and the collected data of a plurality of different pressure-measuring cutting teeth 24 needs to be averaged. The wireless signal receiving device is used to receive the signal, and the received digital signal is recorded in real time through the data acquisition card and saved in the computer. The computer can perform frequency domain conversion and Laplace transform on the cutting force characteristics of the PDC drill cutting teeth 21. processed in other ways.

The above are only preferred embodiments of the present invention, and do not limit the present invention in any form. Although the present invention has been disclosed above with preferred embodiments, it is not intended to limit the present invention. Technical personnel, within the scope of the technical solution of the present invention, can make some changes or modifications to equivalent embodiments of equivalent changes by using the technical content disclosed above, but any content that does not depart from the technical solution of the present invention, according to the present invention Any simple modifications, equivalent changes and modifications made to the above embodiments still belong to the improvement of the technical solution of the present invention.

Claims (8)

1. An intelligent drill bit for monitoring the drilling cutting force in real time comprises a PDC drill bit body (1), a plurality of uniformly distributed PDC drill bit blades (2) are arranged on the drill bit body, and a plurality of PDC drill bit cutting teeth (21) are arranged on the cutting surfaces of the PDC drill bit blades, and is characterized in that each row of PDC drill bit cutting teeth comprises at least one pressure measuring cutting tooth (24); the pressure measuring cutting teeth (24) are provided with pressure monitoring devices, blade internal wiring grooves (22) are formed in the middle of blades of the PDC drill bit, gauge surface wiring grooves (23) are formed in the gauge surface of the PDC drill bit, the lower portions of the gauge surface wiring grooves (23) are connected to a hollow cavity in the sprayer, and the upper portions of the gauge surface wiring grooves are connected to the pressure monitoring devices of the pressure measuring cutting teeth (24); a lead (2413) is arranged in the wiring groove (22) inside the blade wing, a signal conversion module (4) is arranged in the wiring groove (23) on the diameter-keeping surface, the lead (2413) is connected to the signal conversion module (4) from a pressure monitoring device, and the signal conversion module (4) is provided with a wireless signal transmitting device (5);

the pressure monitoring device is a piezoelectric sensor (241), the piezoelectric sensor (241) is embedded in the middle of a PDC drill bit cutting tooth (21) which is processed into a hollow structure to form a pressure measuring cutting tooth (24), and a lead connected with the piezoelectric sensor (241) is connected with the lead

The surface is coated with high-temperature resistant insulating paint;

the piezoelectric sensor (241) comprises a base (2418), the base (2418) is of a hollow cylinder structure, one end of the base (2418) is provided with a round hole with an opening in the middle, the aperture is smaller than the inner diameter of the cylinder, the outer wall of the other end of the base is provided with a section of flange, the flange is internally provided with a plurality of threaded holes, an end sensor top cover (2414) is arranged on one side of the base (2418) with the threaded holes, the sensor top cover (2414) is provided with a plurality of threaded holes corresponding to the base (2418) and is connected with the base through a matched stud (2412), a pressing plate (2415), a first piezoelectric crystal, a conducting plate (2417) and a second piezoelectric crystal are sequentially arranged in the sensor top cover (2414), and are pressed in the base (2418) through the sensor top cover (2414), so that the outer edge of the second piezoelectric crystal at the tail end blocks the round hole of the base (2418);

a section of wire socket (2411) is also arranged above the sensor top cover (2414), the wire socket (2411) is also provided with a threaded hole, and the wire socket is fixed on the sensor top cover (2414) and the base (2418) through a stud (2412);

a conducting wire (2413) is connected to the side surface of the conducting plate (2417), a hole is formed in the sensor top cover (2414), and the conducting wire (2413) penetrates through the hole in the sensor top cover (2414) from the inside of the base (2418) to extend to the outside and is finally connected to the signal conversion module (4);

the diameter of the piezoelectric sensor (241) is 8mm and is smaller than the diameter of the PDC drill bit cutting teeth (21).

2. An intelligent drill bit for real-time monitoring of drilling cutting force according to claim 1, characterized in that the PDC drill bit cutting teeth (21) used for placing the piezoelectric transducer (241), the piezoelectric crystal is processed into a cylinder structure with one closed end, a circular boss is arranged on the inner side of the closed end, the diameter and the depth of the circular boss are completely consistent with the size of a circular hole arranged at one end of a base (2418), the circular boss can just contact with a second piezoelectric crystal close to the end part, the other end of the PDC drill bit cutting tooth (21) cylinder structure is provided with a plurality of threaded holes, the end of each threaded hole is provided with a pressing plate, the pressure strip is provided with a threaded hole corresponding to the cylinder structure of the PDC drill bit cutting teeth (21), the pressing plate and the PDC drill bit cutting teeth (21) are fixed through a stud (2412), and further compresses the piezoelectric transducer (241) within the PDC bit cutter (21).

3. The intelligent drill bit for monitoring the drilling cutting force in real time as claimed in claim 2, characterized in that the lower part of the wiring groove (23) is connected to the side of the hollow cavity inside the PDC drill bit body and connected to the outside of the PDC drill bit body (1) from the hollow cavity, a counter bore is arranged outside the connection position, a signal conversion module (4) is arranged in the counter bore, and a wireless signal transmitting device (5) is arranged in the wiring groove (23) from the signal conversion module (4) to the hollow cavity inside the PDC drill bit body (1).

4. The intelligent drill bit capable of monitoring the drilling cutting force in real time according to any one of claims 1-3, characterized in that the blade internal wiring groove (22) and the gauge face wiring groove (23) are in an L-shaped structure, the top of the L-shaped structure vertically extends from below the piezoelectric sensor (241) to above the hollow cavity inside the PDC drill bit body (1), then horizontally extends to the side face of the PDC drill bit blade (2) to serve as the blade internal wiring groove (22), then a whole block of hollow groove is arranged downwards from the PDC drill bit blade (2) to serve as the gauge face wiring groove (23), and the gauge face wiring groove (23) is connected to the counter bore to form an inverted T-shaped structure with the counter bore.

5. The intelligent drill bit capable of monitoring the drilling cutting force in real time according to claim 4, wherein a T-shaped sealing block is arranged outside the gauge surface wiring groove (23) and the counter bore, is made of hard rubber, and is pressed in an inverted T-shaped structure formed by the gauge surface wiring groove (23) and the counter bore to keep internal and external sealing.

6. The intelligent drill bit capable of monitoring the drilling cutting force in real time according to claim 1, wherein the pressure measuring cutting teeth (24) are obtained by modifying the PDC drill bit cutting teeth (21) arranged in the middle of the PDC drill bit blades (2), and if the number of the PDC drill bit cutting teeth (21) on the PDC drill bit blades (2) is even, the PDC drill bit cutting teeth (21) close to the axis of the PDC drill bit body (1) in the middle 2 PDC drill bit cutting teeth (21) are selected for modification.

7. The intelligent drill bit for real-time monitoring of drilling cutting force according to claim 1, wherein a matched wireless signal receiver, a data acquisition card and a computer are arranged at a well site.

8. A method of operating a smart drill bit for real-time monitoring of drilling cutting force according to any one of claims 1-7, comprising the steps of:

when the drill bit works, the PDC drill bit cutting teeth (21) on the blades of the PDC drill bit cut the stratum, at the moment, the cutting force is measured by a piezoelectric sensor (241) on a pressure measuring cutting tooth (24), an electric signal is transmitted to a signal conversion module (4) through a lead (2413), the electric signal is subjected to charge amplification and voltage amplification in the signal conversion module (4), the voltage which meets the requirement and is output by an amplifier is filtered by a low-pass filter to be changed into a low-frequency voltage signal, the low-frequency voltage signal is changed into a discrete signal after being sampled and held by a sample and hold circuit in a sample and hold circuit unit, the discrete signal is changed into a digital signal after being subjected to A/D conversion, the processed digital signal is sent to a wireless signal transmitting device (5) and then sent to the ground, the signal is received by a wireless signal receiving device and is transmitted to a computer through a data acquisition card, recording and storing the collected electric signals by a computer; and/or after the processed digital signal is sent to the wireless signal transmitting device (5), the processed digital signal is stored in the wireless signal transmitting device (5) and the data condition in the digital signal is analyzed after the digital signal is taken out.

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