CN116641695B - Self-adaptive drilling tool and drilling process - Google Patents

Abstract

The invention relates to an adaptive drilling tool and a drilling process, and belongs to the technical field of geological survey. The technical solution is: the pressure control device (9) includes an airbag body (13), a connecting piece (14), a connecting piece (15) and a communication port (16). The airbag body (13) is a hollow structure. A communication port (16) is provided on the side wall of the air bag body (13). The space between the air bag body (13) and the outer core tube (4) forms a water gap. The two ends of the air bag body (13) are respectively provided with a connecting piece. (14) and connecting piece two (15), connecting piece one (14) is connected to the suspension joint (83) of the elastic clamp assembly (8), and connecting piece two (15) is connected to the inner core tube (3). The positive effect of the present invention is that by installing a pressure control device and a flow control device, it can adapt to drilling in soft rock formations or hard rock formations without frequent replacement of parts.

Description

An adaptive drilling tool and drilling process

Technical field

The invention relates to an adaptive drilling tool and a drilling process, and belongs to the technical field of geological survey.

Background technique

The development of wireline core drilling technology is becoming increasingly mature, and its applications in solid mineral deposit exploration, shale gas, scientific drilling, etc. are also increasing. However, in geological drilling, the geological conditions are very complex, and the stratum changes frequently during the drilling process. In a good mining area, the stratum may change within a few hundred meters, but in most mining areas, it may change within a few meters or dozens of meters. When the drilling process parameters remain unchanged, changes in the formation will directly affect the drilling efficiency and even cause in-hole accidents. At this time, it is necessary to adjust drilling process parameters such as drilling pressure on bit and pump pressure to adapt to formation conditions and reduce the occurrence of accidents. The pump pressure during drilling directly affects the drilling efficiency of the drill bit and the stability of the hole wall. Therefore, it is necessary to adjust the water clearance of the drilling tool or change the pump volume to effectively change the pump pressure to a reasonable range. The pump volume is The adjustment can be completed on the ground, but the adjustment of the water clearance requires lifting the drilling tool from the hole and replacing parts. In many cases, the adjustment of the pump volume is limited or cannot be adjusted, and the adjustment can only be done by replacing parts. The water gap is completed, which makes the cost prohibitive and frequent replacement of parts is very troublesome.

Contents of the invention

The purpose of the present invention is to provide an adaptive drilling tool and a drilling process. By installing a pressure control device and a flow control device in the drilling tool, the frequent replacement of parts due to changes in the formation is reduced, and the above-mentioned problems existing in the background technology are solved.

The technical solution of the present invention is:

An adaptive drilling tool includes an elastic clamp assembly, an inner core pipe and a circlip seat arranged in sequence in an outer core tube. A drill bit is provided at the end of the outer core tube; there is a spring clamp assembly between the elastic clamp assembly and the inner core tube. There is a pressure control device. The pressure control device includes an air bag body, a connecting piece 1, a connecting piece 2 and a communication port. The air bag body is a hollow structure. A communication port is provided on the side wall of the air bag body. The air bag body is connected to the outer core tube. The space between them forms a water gap, and the two ends of the air bag body are respectively provided with a connecting piece one and a connecting piece two. The connecting piece one is connected to the suspension joint of the elastic card assembly, and the connecting piece two is connected to the inner core tube.

Further, the elastic card assembly is provided with a flow control device. The flow control device includes a flow valve body, a position adjustment valve block and an adjustment knob; the flow valve body is a cylindrical structure with an opening at one end, and the flow valve body communicates with the flow valve through the opening. The internal main water channel of the elastic card assembly is connected. The outer wall of the flow valve body is provided with an annular groove. The inner wall of the flow valve body is provided with multiple layers of water outlets arranged along the axial direction; the water outlet passes through the annular groove and the elastic card assembly. The external main waterway is connected, and the position adjustment valve block is threadedly connected to the flow valve body. The position adjustment valve block is equipped with an adjustment knob. By rotating the adjustment knob, the position adjustment valve block is adjusted to the position of the flow valve body to increase or decrease the exposure of the outlet hole. The number of layers can be adjusted to adjust the water flow of the flow valve body.

Further, the elastic card seat and the suspension seat of the elastic card assembly are threadedly connected to form a cavity inside. The internal cavity of the elastic card seat is provided with an internal main waterway, and the internal cavity of the suspension seat is provided with a flow valve body. , the open end of the flow valve body is in contact with the end of the elastic card seat; the internal main water channel, the inner cavity of the flow valve body, the outlet hole, the annular groove and the external main water channel are connected in sequence to form a water flow channel.

Further, the inner wall of the flow valve body is provided with 2-10 layers of water outlets arranged along the axial direction, and multiple water outlets in each layer are distributed along the circumferential direction on the inner wall of the flow valve body.

Further, a seat ring is provided on the inner wall of the outer core tube, and a suspension ring is provided outside the suspension seat. The suspension ring is stuck on the seat ring to position the spring assembly. There is a sealing ring between the suspension seat and the seat ring.

The drill bit, cartridge assembly, outer core tube, inner core tube and circlip seat involved in the present invention are all well-known and common mechanisms in this field.

An adaptive drilling process, using the above-mentioned adaptive drilling tools, the steps are as follows:

① The process of adjusting the internal pressure of the adaptive drilling tool through the pressure control device is as follows:

When the adaptive drilling tool encounters a hard rock layer during drilling, the footage rate slows down. In order to maintain the footage efficiency, the drilling pressure increases. As the drilling pressure increases, the upward force on the circlip seat and the inner core tube gradually increases. When the force is transmitted to the pressure control device, the air bag body will expand and the outer diameter will increase, thereby reducing the water gap between the air bag body and the outer core tube, causing the mud pump pressure to increase. At this time, the mud can be reduced The pump flow rate is adjusted to stabilize the pump pressure, and at the same time, the rotation speed is increased, the drilling pressure is reduced, and the footage efficiency is maintained;

When the adaptive drilling tool encounters a soft formation while drilling, because the initial parameters of the pressure control device are set according to the soft formation, the outer diameter of the air bag body of the pressure control device will not change or become slightly larger. The water passing gap between them will not change or become slightly smaller, the pump pressure and drilling pressure will not change significantly, and drilling can be normal;

When drilling in strata with frequent interactions between soft and hard, frequent changes in drilling parameters will affect drilling efficiency and cause accidents in the hole. You can change the expansion of the airbag body by adjusting the drilling weight without changing the pump volume and speed. status to achieve the stability of the weight on bit;

②The process of adjusting the internal flow of the adaptive drilling tool through the flow control device is as follows:

Because each time drilling is completed, the inner drilling tool will be pulled out of the hole and the condition of the core taken out will be checked. The water flow rate of the flow control device can be adjusted according to the condition of the core to adapt to different strata;

When it is known that the formation is a hard rock layer, before drilling the hole, turn the adjustment knob to reduce the number of exposed layers of the water outlet, adjust the water flow of the flow control device, while keeping the water supply flow of the mud pump unchanged, and increase the water jet speed. When the adaptive drilling tool is working, it can stir up the rock powder at the bottom of the hole, so that the mud and rock powder can fully contact, so that the mud can carry the rock powder to the ground;

When it is known that the formation is soft, before drilling, turn the adjustment knob to increase the number of exposed layers of water outlets, increase the water flow of the flow control device, and increase the water supply flow of the mud pump at the same time, so that a large amount of mud can reach Bottom of the hole; the water flow rate of the flow control device and the flow rate of the mud pump are increased at the same time, which can maintain stable pump pressure under large flow rates and avoid sudden changes in pump pressure;

When drilling into soft and hard strata, or when the stratum conditions are unknown, adjust the water flow of the flow control device according to each core taken out, then put the inner drilling tool into the hole, and repeat the above steps to adapt to drilling in different strata.

Positive effects of the present invention: by arranging a pressure control device between the cartridge assembly and the inner core tube, the type of formation encountered can be known through the expansion state of the air bag body of the pressure control device, so as to adjust the drilling pressure and increase the drilling pressure. Within a reasonable range; at the same time, a flow control device is installed in the cartridge assembly. By adjusting the water flow of the flow control device, the water jet speed and stable pump pressure can be changed, so that it can adapt to soft rock formations or hard rock strata without frequent replacement of parts. Drilling into rock formations.

Description of the drawings

Figure 1 is a schematic structural diagram of the flow control device of the present invention;

Figure 2 is a schematic diagram of the pressure control device of the present invention when there is no pressure or when the pressure is small;

Figure 3 is a schematic diagram of the pressure control device according to the present invention when it is under high pressure;

Figure 4 is a schematic diagram of soft formation drilling according to Embodiment 1 of the present invention;

Figure 5 is a schematic diagram of hard formation drilling according to Embodiment 1 of the present invention;

Figure 6 is a schematic diagram of soft formation drilling according to Embodiment 2 of the present invention;

Figure 7 is a schematic diagram of hard formation drilling according to Embodiment 2 of the present invention;

Figure 8 is a schematic structural diagram of Embodiment 3 of the present invention;

In the picture: drill bit 1, circlip seat 2, inner core tube 3, outer core tube 4, flow control device 5, seat ring 6, suspension ring 7, spring clip assembly 8, spring clip seat 81, suspension seat 82, suspension Joint 83, pressure control device 9, flow valve body 10, adjustment valve block 11, adjustment knob 12, annular groove 101, water outlet hole 102, air bag body 13, connector one 14, connector two 15, communication port 16, internal main Waterway 17, external main waterway 18.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and examples:

An adaptive drilling tool includes a drill bit 1, a circlip seat 2, an inner core tube 3, an outer core tube 4, a seat ring 6 and a suspension ring 7. The drill bit 1, outer core tube 4 and seat ring 6 form an outer drilling tool, and the elastic clamp assembly 8, inner core tube 3, suspension ring 7 and circlip seat 2 form an inner drilling tool. The drill bit 1 is arranged at the end of the outer core tube 4, the seat ring 6 is arranged on the inner wall of the outer core tube 4, the spring clamp assembly 8, the inner core tube 3 and the circlip seat 2 are successively arranged inside the outer core tube 4, and there is a suspension seat 82 outside Suspension ring 7, the suspension ring 7 is stuck on the seat ring 6.

Referring to Figures 2, 3, 4 and 5, Embodiment 1 is to install a pressure control device 9 separately in an adaptive drilling tool:

In this embodiment, the rest of the structure of the adaptive drilling tool remains unchanged. A pressure control device 9 is installed between the elastic clamp assembly 8 and the inner core tube 3. The pressure control device 9 includes an air bag body 13 and a connecting piece 14. , connector two 15 and communication port 16, the air bag body 13 is a hollow structure, the side wall of the air bag body 13 is provided with a communication port 16, the space between the air bag body 13 and the outer core tube 4 forms a water gap, the air bag The first connecting piece 14 and the second connecting piece 15 are respectively provided at both ends of the body 13 . The first connecting piece 14 is connected to the suspension joint 83 of the elastic clamp assembly 8 , and the second connecting piece 15 is connected to the inner core tube 3 .

The airbag body 13 is made of material capable of withstanding high pressure.

The airbag body 13 is connected to the outside world through the communication port 16 to maintain the balance of pressure inside and outside the airbag under different hole depths.

The airbag body 13 can expand when subjected to axial force.

During the drilling process, the force exerted by the core on the inner core tube 3 is transmitted to the air bag body 13, causing the air bag body 13 to expand, thus changing the water passing area of the water path and causing changes in the ground mud pump pressure.

When drilling, you will encounter different conditions of soft formations, hard formations, and formations with frequent soft and hard interaction. When encountering different formation conditions, the process of the pressure control device 9 adjusting the internal pressure of the adaptive drilling tool is as follows:

First, the outer drilling tool is assembled, the pressure control device 9 is installed on the cartridge assembly 8, the inner drilling tool is assembled and installed into the outer drilling tool, and the assembled double-tube drilling tool is sent to the drill pipe string. to the bottom of the hole. Turn on the mud pump to supply flushing fluid into the hole, and drill with rotation. Set the drilling parameters (pump volume, drilling pressure, rotation speed) according to the footage of the soft formation.

Referring to Figure 4, when the adaptive drilling tool encounters a soft formation, because the initial parameters of the pressure control device 9 are set according to the soft formation, the outer diameter of the air bag body 13 of the pressure control device 9 will not change or become slightly larger. , the water gap between the air bag body 13 and the outer core tube 4 will not change or become slightly smaller, the pump pressure and drilling pressure will not change significantly, and drilling can be performed normally.

Referring to Figure 5, when the adaptive drilling tool encounters a hard rock layer, the footage rate slows down. In order to maintain the footage efficiency, the drilling pressure increases. As the drilling pressure increases, the circlip seat 2 and the inner core tube 3 are affected by The upward force gradually increases, and when the force is transmitted to the pressure control device 9, the air bag body 13 will expand and the outer diameter will increase, thereby reducing the water gap between the air bag body 13 and the outer core tube 4, causing the mud pump to When the pump pressure increases, the mud pump flow rate can be reduced to stabilize the pump pressure. At the same time, the rotation speed can be increased to reduce the drilling pressure and maintain footage efficiency.

When drilling in strata with frequent interactions between soft and hard, frequent changes in drilling parameters will affect drilling efficiency and cause accidents in the hole. Therefore, the pump volume and rotation speed can be adjusted without changing the pump volume and rotational speed, and the air bag body 13 can be changed by adjusting the drilling weight. expansion state to achieve the stability of the weight on bit.

The use of the pressure control device 9 can sense formation changes in the hole in real time, adjust drilling parameters in real time according to changes in the formation, and reduce the occurrence of accidents in the hole.

Referring to Figures 1, 6 and 7, the second embodiment is to install the flow control device 5 separately in the adaptive drilling tool. The flow control device 5 can be installed on the cartridge assembly 8 of any structure:

There are two installation methods for the flow control device 5. One is to install it on the main waterway of the original elastic card assembly. Generally, the flow valve body 10 is designed as a hollow cylindrical structure. The flow channel is designed inside the flow valve body 10 and is consistent with the original elastic card. The main waterway of the assembly is connected, and the other is to replace the parts of the original elastic card assembly. The flow valve body 10 is used as the 8 part of the elastic card assembly, and a water flow control channel is provided inside.

In this embodiment, the rest of the structure of the adaptive drilling tool remains unchanged, and a flow control device 5 is installed in the cartridge assembly 8. The flow control device 5 includes a flow valve body 10, a position adjustment valve block 11 and an adjustment knob 12; so The elastic card seat 81 and the suspension seat 82 of the elastic card assembly 8 are threadedly connected to form a cavity inside. The internal main waterway 17 is provided in the internal cavity of the elastic card seat 81, and the internal cavity of the suspension seat 82 is provided with a flow rate. The flow valve body 10 is a cylindrical structure with one end open. The open end of the flow valve body 10 is in contact with the end of the elastic card seat 81. The flow valve body 10 communicates with the internal main water channel 17 of the elastic card assembly 8 through this opening. Connected, the outer wall of the flow valve body 10 is provided with an annular groove 101, and the inner wall of the flow valve body 10 is provided with multiple layers of water outlets 102 arranged along the axial direction. The multiple water outlets 102 in each layer are evenly distributed along the circumferential direction. on the inner wall of the flow valve body 10. The water outlet hole 102 is connected to the external main water channel 18 of the cartridge assembly 8 through the annular groove 101. The position adjustment valve block 11 is threadedly connected in the flow valve body 10. The position adjustment valve block 11 is provided with an adjustment knob 12. By rotating the adjustment knob 12 Then adjust the position of the valve block 11 to the position of the flow valve body 10. All water passes through the flow valve body 10. By rotating the adjustment knob 12, the number of exposed layers of the water outlet holes 102 is increased or decreased, thereby adjusting the water flow of the flow valve body 10. The internal main water channel 17, the inner cavity of the flow valve body 10, the outlet hole 102, the annular groove 101 and the external main water channel 18 are connected in sequence to form a water flow channel.

When drilling, you will encounter different conditions such as soft formations, hard formations, and formations with frequent soft and hard interaction. When encountering different formation conditions, the process of the flow control device 5 adjusting the internal flow of the adaptive drilling tool is as follows:

First, the outer drilling tool is assembled, the flow control device 5 is installed on the cartridge assembly 8, the inner drilling tool is assembled and installed into the outer drilling tool, and the assembled double-tube drilling tool is sent to the drill pipe string. to the bottom of the hole. Turn on the mud pump to supply flushing fluid into the hole and rotate the drilling.

Generally, after drilling 3 meters, the inner drilling tool will be lifted out of the hole, and rope core will be taken to check the condition of the core taken out. The water flow rate of the flow control device 5 can be adjusted according to the condition of the core to adapt to different strata;

When it is known that the formation is a hard rock layer, before drilling, rotate the adjustment knob 12 to reduce the number of exposed layers of the water outlet holes 102 and reduce the water flow of the flow control device 5 while keeping the water supply flow of the mud pump unchanged and increasing the water flow. The injection speed, when the adaptive drilling tool is working, can stir up the rock powder at the bottom of the hole, so that the mud and rock powder can fully contact, making it easier for the mud to carry the rock powder to the ground;

When it is known that the formation is soft, before drilling, rotate the adjustment knob 12 to increase the number of exposed layers of the water outlet holes 102, increase the water flow of the flow control device 5, and at the same time increase the water supply flow of the mud pump, which can make a large number of The mud reaches the bottom of the hole; the water flow rate of the flow control device 5 and the flow rate of the mud pump are increased at the same time, which can maintain stable pump pressure under large flow rates and avoid sudden changes in pump pressure;

When drilling into soft and hard strata, or when the stratum conditions are unknown, adjust the water flow of the flow control device 5 according to each core taken out, and then put the inner drilling tool into the hole, and repeat the above steps to adapt to drilling in different strata.

In all the above embodiments, the outer diameter of the drill bit 1 is designed to be enlarged. According to the general conditions of the formation to be drilled, the outer diameter of the drill bit 1 is increased by 2-8 mm to increase the inner and outer annulus gaps. According to the long-term use of existing drill bits In the case of in-hole footage, a drill bit 1 with an enlarged outer diameter theoretically increases the amount of rock cutting and affects the footage efficiency. However, in practical applications, its footage efficiency is affected by factors such as drilling pressure, pump volume, and rotational speed. There is no obvious difference. In applications in multiple mining areas, the drill bit 1 with an enlarged outer diameter can achieve a daily footage of more than 30 meters in drilling soft and hard formations.

Referring to Figure 8, the third embodiment is to install the flow control device 5 and the pressure control device 9 simultaneously in the adaptive drilling tool. The installation structure and function of the flow control device 5 and the pressure control device 9 are the same as those in the first and second embodiments. , I won’t go into details here.

More specific implementation:

1. Take the drilling of 95 adaptive drilling tools installed with flow control device 5 as an example:

1. Assemble the outer drilling tools of the 95 adaptive drilling tool. The outer diameter of the drill bit 1 is 102mm (the outer diameter is 7mm larger than the ordinary drill bit), and the inner diameter is 63.5mm. Install the flow control device 5 in the cartridge assembly 8 On the machine, assemble the inner drilling tool and install it into the outer drilling tool. Send the assembled double-tube drilling tool to the bottom of the hole with the drill pipe string.

2. Turn on the mud pump to supply flushing fluid into the hole and rotate the drilling. The initial drilling parameters are: pump volume 90L/min, drilling pressure 30kN, rotating speed 360r/min.

3. If the adaptive drilling tool encounters a hard rock layer while drilling, keep the water supply flow rate of the mud pump unchanged and reduce the water flow rate of the flow control device 5 before going down the well.

4. If the adaptive drilling tool encounters a soft formation during drilling, increase the water flow rate of the flow control device 5 and increase the flow rate of the mud pump to 145L/min before going down the well. This can allow a large amount of mud to reach the bottom of the hole and maintain The pump pressure remains unchanged.

5. When drilling into soft and hard strata that alternate with each other or when the stratum conditions are unknown, the water flow rate of the flow control device 5 can be adjusted according to the conditions of the core taken out in each footage.

6. After each round of drilling is completed, lift the inner drilling tool out of the hole, check the condition of the core, and adjust the flow control device 5 according to the condition of the core to suit the formation drilling.

7. Insert the inner drilling tool into the hole, repeat the above steps, and adjust the flow control device 5 in time if there are changes in the formation.

2. Taking the drilling of 95 adaptive drilling tools with pressure control device 9 as an example

1. Assemble the 95 outer drilling tool. The outer diameter of the drill bit 1 is 102mm (the outer diameter is 7mm larger than the ordinary drill bit), and the inner diameter is 63.5mm. Install the pressure control device 9 on the cartridge assembly 8, and install the inner drilling tool. Assemble and install into the outer drilling tool, and send the assembled double-tube drilling tool to the bottom of the hole with the drill pipe string.

2. Turn on the mud pump to supply flushing fluid into the hole and rotate the drilling. The initial drilling parameters are: pump volume 145L/min, drilling weight 30kN, and rotation speed 360r/min.

3. If the footage rate slows down during drilling, in order to maintain the footage efficiency, it is necessary to increase the drilling pressure to 40-50kN. As the drilling pressure increases, the mud pump pressure increases, indicating that the air bag body 13 expands and the air bag body 13 If the water gap between the outer core pipe 4 and the outer core pipe 4 is reduced, the drilling encounters a hard rock formation. At this time, the mud pump flow rate can be reduced to a stable pump pressure, and the rotation speed can be increased to 500-600r/min, and the drilling pressure can be reduced to 20kN, maintaining footage efficiency.

4. If the footage rate remains unchanged during drilling and the pump pressure does not change significantly, then the drilling encounters soft formations.

5. When drilling in formations where soft and hard interactions are frequent, the pump volume and rotation speed can be adjusted in real time without changing the pump volume and rotation speed, and the pressure on bit can be stabilized by changing the expansion state of the air bag body 13.

6. After each round of drilling is completed, lift the inner drilling tool out of the hole, check the condition of the core, and adjust the drilling parameters for the next round according to the condition of the core.

7. Insert the inner drilling tool into the hole, repeat the above steps, and adjust the flow control device 5 in time if there are changes in the formation.

Claims (5)

1. A self-adaptive drilling tool comprises a spring clamping assembly (8), an inner core tube (3) and a clamp spring seat (2) which are sequentially arranged in an outer core tube (4), wherein a drill bit (1) is arranged at the end part of the outer core tube (4); the method is characterized in that: the utility model provides a bullet card assembly (8) is equipped with pressure control device (9) between inner core tube (3), pressure control device (9) contain gasbag body (13), connecting piece one (14), connecting piece two (15) and intercommunication mouth (16), gasbag body (13) are hollow structure, are equipped with intercommunication mouth (16) on the lateral wall of gasbag body (13), and the space between gasbag body (13) and outer core tube (4) forms the water clearance, and the both ends of gasbag body (13) are equipped with connecting piece one (14) and connecting piece two (15) respectively, and connecting piece one (14) are connected with suspension joint (83) of bullet card assembly (8), and connecting piece two (15) are connected with inner core tube (3).

2. An adaptive drilling tool as recited in claim 1, wherein: a flow control device (5) is arranged in the spring card assembly (8), and the flow control device (5) comprises a flow valve body (10), a position adjusting valve block (11) and an adjusting knob (12); the flow valve body (10) is of a cylindrical structure with one end open, the flow valve body (10) is communicated with an internal main waterway (17) of the spring card assembly (8) through the opening, an annular groove (101) is arranged on the outer wall of the flow valve body (10), and a plurality of layers of water outlet holes (102) which are axially arranged are arranged on the inner wall of the flow valve body (10); the water outlet hole (102) is communicated with an external main waterway (18) of the spring clip assembly (8) through an annular groove (101), the position adjusting valve block (11) is in threaded connection with the inside of the flow valve body (10), the position adjusting valve block (11) is provided with an adjusting knob (12), the position of the position adjusting valve block (11) on the flow valve body (10) is adjusted by rotating the adjusting knob (12), the number of exposed layers of the water outlet hole (102) is increased or reduced, and the water flow of the flow valve body (10) is adjusted.

3. An adaptive drilling tool as recited in claim 2, wherein: the bullet cassette (81) of bullet card assembly (8) and hang the back inside formation cavity of seat (82) threaded connection, be equipped with inside main water route (17) in the inside cavity of bullet cassette (81), be equipped with flow valve body (10) in the inside cavity of suspension seat (82), the open end of flow valve body (10) and bullet cassette (81) tip contact; the inner main waterway (17), the inner cavity of the flow valve body (10), the water outlet hole (102), the annular groove (101) and the outer main waterway (18) are sequentially communicated to form a water flow channel.

4. An adaptive drilling tool according to claim 3, wherein: a seat ring (6) is arranged on the inner wall of the outer core tube (4), a suspension ring (7) is arranged outside the suspension seat (82), and the suspension ring (7) is clamped on the seat ring (6).

5. An adaptive drilling process using the adaptive drilling tool according to any one of claims 2-4, characterized in that:

(1) the process of adjusting the internal pressure of the self-adaptive drilling tool by the pressure control device (9) is as follows:

when the self-adaptive drilling tool drills into hard rock stratum, the length feeding speed is reduced, in order to maintain the length feeding efficiency, the drilling pressure is increased, along with the increase of the drilling pressure, the clamp spring seat (2) and the inner core tube (3) are gradually increased by upward force, and when the force is transmitted to the pressure control device (9), the air bag body (13) is expanded to cause the outer diameter to be increased, so that the water passing gap between the air bag body (13) and the outer core tube (4) is reduced, the pumping pressure of a slurry pump is increased, the flow rate of the slurry pump can be reduced to be stable, the rotating speed is increased, the drilling pressure is reduced, and the length feeding efficiency is maintained;

when the self-adaptive drilling tool drills into soft stratum, because the initial parameters of the pressure control device (9) are set according to the soft stratum, the outer diameter of the air bag body (13) of the pressure control device (9) is not changed or slightly increased, the water gap between the air bag body (13) and the outer core barrel (4) is not changed or slightly reduced, the pumping pressure and the drilling pressure are not obviously changed, and the drilling can be performed normally;

when the soft and hard interaction is carried out on frequent stratum drilling, the drilling efficiency is influenced and the occurrence of in-hole accidents is caused due to frequent change of drilling parameters, the pump quantity and the rotating speed can not be changed, and the stability of the drilling pressure is realized by adjusting the expansion state of the air bag body (13);

(2) the process of adjusting the internal flow of the self-adaptive drilling tool through the flow control device (5) is as follows:

the inner drilling tool is lifted out of the hole after each drilling is completed, the condition of the taken core is checked, and the water flow of the flow control device (5) can be adjusted according to the condition of the core so as to adapt to different stratum;

when the stratum is known to be a hard stratum, the adjusting knob (12) is rotated before the stratum is drilled, the number of exposed layers of the water outlet hole (102) is reduced, the water flow of the flow control device (5) is reduced, meanwhile, the water supply flow of the slurry pump is kept unchanged, the water flow injection speed is increased, and when the self-adaptive drilling tool works, rock powder at the bottom of the hole can be stirred, so that slurry and the rock powder can be fully contacted, and the slurry is convenient for carrying the rock powder to the ground;

when the stratum is known to be a soft stratum, the adjusting knob (12) is rotated before the stratum is drilled, the number of exposed layers of the water outlet holes (102) is increased, the water flow of the flow control device (5) is increased, and meanwhile, the water supply flow of the slurry pump is increased, so that a large amount of slurry can reach the bottom of the holes; the water flow of the flow control device (5) and the flow of the slurry pump are simultaneously increased, so that stable pumping pressure can be maintained under high flow, and abrupt change of the pumping pressure is avoided;

when the soft and hard interactive stratum is drilled or the stratum condition is unknown, the water flow of the flow control device (5) is adjusted according to the condition of taking out the rock core each time, then an inner drilling tool is thrown into the hole, and the steps are repeated so as to adapt to drilling of different strata.