CN214787166U - Under-pressure composite drilling device for deep high-temperature well - Google Patents

Abstract

The utility model discloses an under-pressure composite drilling device for a deep high-temperature well, wherein a ground drilling part comprises a drilling machine, a drilling fluid cooling system and a drilling fluid circulating system; the underground drilling tool part comprises a drill rod, a drill collar, a power assembly, a near-bit pressure reducing short joint and a drill bit; the near-bit pressure reducing short section is provided with an annular channel; a plurality of suction flow passages are uniformly formed in the circumferential direction of the annular channel; a sand mixing throat pipe communicated with the suction flow channel is arranged on the outer side wall of the near-bit pressure reducing short section in the circumferential direction; and a suction flow passage is also formed on the outer side wall of the near-bit pressure reducing short section and is communicated with the suction flow passage and a node of the sand mulling throat pipe. The utility model discloses aim at utilizing comprehensively that impact, gyration, three kinds of modes combined action of thermal fracture destroy the shaft bottom rock, nearly drill bit decompression nipple joint produces local negative pressure in the annular space passageway of nearly drill bit position, and the suction is just by carrying the drilling fluid that returns to ground on the detritus after gathering the jet blow shaft bottom, reduces the positive pressure differential in shaft bottom, reduces and presses the effect of holding.

Description

Under-pressure composite drilling device for deep high-temperature well

Technical Field

The utility model relates to a vertical well, directional well, horizontal well technical field, more specifically the utility model relates to a deep high temperature well is with under-voltage composite drilling equipment that says so.

Background

In the deep earth resource exploration and development process, drilling is the most effective means for obtaining underground material data and establishing a production channel, but deep high-temperature drilling faces the problems of high rock hardness, low rock breaking efficiency, adverse effect of high temperature on drilling fluid and drilling tools, insufficient deep bottom hole power and the like, and the exploration and development progress is seriously influenced. The conventional rock breaking method is rotary drilling by a rotary table or composite drilling by a screw drilling tool, but the backing pressure of the drilling tool is gradually enhanced along with the increase of the hole depth, the power transmitted to the bottom of a well by the rotary table is insufficient, and the rotary power can be only provided in the rock breaking process by the screw drilling tool or the turbine drilling tool, so that the rock breaking effect on hard rock is poor.

Therefore, it is an urgent need to solve the above-mentioned problems by those skilled in the art to provide a drilling device that reduces the pressure holding effect, increases the rate of penetration, prolongs the life of the drill bit, and increases the single-pass drilling length.

SUMMERY OF THE UTILITY MODEL

In view of this, the utility model provides an under-voltage composite well drilling device is used to deep part high temperature well aims at solving above-mentioned technical problem.

In order to achieve the above purpose, the utility model adopts the following technical scheme:

an under-pressure composite drilling device for a deep high-temperature well comprises:

a surface drilling section; the ground drilling part comprises a drilling machine and a drilling fluid cooling system connected with the drilling machine through a circulating pipeline, and drilling fluid circulating systems positioned on two sides of the drilling fluid cooling system are also installed on the circulating pipeline in series;

a downhole drilling tool portion; the downhole drilling tool part comprises a drill rod, and the drill rod is connected with the drilling machine and communicated with the circulating pipeline; the drill collar, the power assembly, the near-bit pressure reducing nipple and the drill bit are sequentially connected with the drill rod; the power assembly is used for providing drilling power and measuring drilling parameters; the near-bit pressure reducing nipple is provided with an annular channel axially communicated with the drill rod; a plurality of suction flow passages are uniformly formed in the circumferential direction of the annular channel; a sand mixing throat pipe communicated with the suction flow channel is arranged on the outer side wall of the near-bit pressure reducing short section in the circumferential direction; the outer side wall of the near-bit pressure reducing short section is also provided with a suction flow passage, and the suction flow passage is communicated with the suction flow passage and a node of the sand mulling throat pipe; the bit front end has a shaped nozzle in communication with the annulus passage.

Through the technical scheme, the utility model provides a drilling equipment aims at the comprehensive utilization impact, the gyration, three kinds of mode combined action destruction shaft bottom rocks are ruptured to the heat, nearly drill bit decompression nipple joint utilizes venturi effect or vortex suction principle to produce local negative pressure in the annular space passageway of nearly drill bit position, the suction just carries the detritus to go back to the drilling fluid on ground after the shaft bottom by gathering the nozzle blowout, reduce the positive pressure differential in shaft bottom, reduce and press the effect of holding, improve the mechanical drilling speed, the extension drill bit life-span, increase single trip footage.

Preferably, in the under-pressure composite drilling device for the deep high-temperature well, the suction flow channel is integrally communicated with the sand mixing throat pipe and obliquely extends from the inner wall of the annular channel to the direction far away from the drill bit; the suction flow channel extends from the outer side wall of the near-bit pressure reduction short section to the direction far away from the drill bit in an inclined mode. Local negative pressure is generated in an annular channel close to a drill bit by using a Venturi tube effect or a vortex suction principle, drilling fluid carrying rock debris just ejected from an energy-gathering nozzle is sucked, positive pressure difference at the bottom of a well is reduced, and a pressure holding effect is reduced.

Preferably, in the above-mentioned deep portion high temperature is undervoltage composite drilling device for well, the power component adopts different combination modes according to different well sections, and is specific:

when the straight well section is drilled, the bottom end of the drill rod is sequentially connected with a drill collar and a high-temperature-resistant composite power drilling tool, and the high-temperature-resistant composite power drilling tool is connected with the near-bit pressure reducing nipple.

When the directional section drilling is carried out, the bottom end of the drill rod is sequentially connected with a drill collar or a weighted drill rod, a high-temperature-resistant MWD (measurement while drilling), a high-temperature-resistant composite power drilling tool and a near-bit measuring nipple, and the near-bit measuring nipple is connected with the near-bit pressure reducing nipple.

When the horizontal section is drilled, the bottom end of the drill rod is sequentially connected with a drill collar or a weighted drill rod, an additional drill rod, a high-temperature-resistant MWD (measurement while drilling), a high-temperature-resistant composite power drilling tool and a near-bit measuring nipple, and the near-bit measuring nipple is connected with the near-bit pressure reducing nipple.

Preferably, in the above-mentioned undervoltage composite drilling device for the deep high-temperature well, the drilling fluid cooling system is an air cooling mechanism that uses an axial fan to sweep and cool the sprayed drilling fluid, or a liquid cooling mechanism that uses a secondary refrigerant and the drilling fluid to perform non-contact heat exchange and cooling in a convection heat exchanger. The temperature difference between the drilling fluid and the rock at the bottom of the hole is increased, and further the thermal stress in the rock is increased.

Preferably, in the undervoltage composite drilling device for the deep high-temperature well, the drilling fluid circulation system comprises a vibrating screen, a sand remover, a mud remover, a centrifuge, a degasser and a mud pump, and is used for establishing ground circulation of the drilling fluid and removing rock debris particles in the drilling fluid.

The utility model also provides an under-voltage composite drilling technology for deep high temperature well specifically includes following steps:

s1, after the drill is drilled to the bottom, a pump is started to drill circularly, the high-pressure drilling fluid drives the power assembly to generate torsion and impact, the drill bit gradually bites into the stratum rock under the combined action of the drilling pressure and the periodic impact force, and the drill bit rotates to cut off the peripheral rock under the action of the torque of the power assembly;

s2, enabling the low-temperature drilling fluid cooled by the drilling fluid cooling system to flow downwards to flow through the near-bit pressure reducing nipple, enabling most of the drilling fluid to continuously flow downwards to flow through an energy-gathering nozzle of the bit and then impact the rock in a high-speed jet flow mode, and enabling the rock to generate microcracks in the rock by utilizing thermal stress and jet flow impact force generated in the rock by the temperature difference between the high-temperature rock and the low-temperature drilling fluid, so that the rock is broken under the action of torsion and impact loads; a small amount of drilling fluid generates negative pressure after flowing through the suction flow passage, and the drilling fluid returning upwards in the annular passage is sucked through the suction flow passage, so that the bottom hole pressure at the drill bit is reduced, and the pressure holding effect is weakened.

In step S1, the drilling pressure is 100-120kN and the displacement is 30L/S during drilling of the hard rock stratum.

When the measured bit pressure of the drill bit is smaller than the surface apparent bit pressure in the drilling process, the composite drilling torque is low, and the sliding drilling torque is basically unchanged, the pressure supporting condition possibly occurs underground, short-lift operation is carried out, the well wall is pulled and scratched, the detritus bed is damaged, the purification of the drilling fluid is enhanced, and meanwhile, a proper amount of lubricant is added into the drilling fluid; when the torque and the pump pressure suddenly rise during drilling, accidents such as roller cone falling and palm breaking of a drill bit can occur, and then the drill is taken out for inspection; when the torque and the pump pressure are suddenly reduced during drilling, and the high-temperature-resistant composite power drilling tool possibly has the abnormalities such as drilling tool failure and the like, observing whether a vibrating screen in a drilling fluid circulating system returns abnormal objects or not, and if so, carrying out tripping inspection; when the torque is unchanged during drilling and the pump pressure is gradually reduced, the upper drill rod or drill collar is likely to have puncture, and then the drilling is started for inspection; when the drill is stuck, starting the pump for circulation, judging that the stuck point is positioned near the drill when the torque of the drill is larger, and performing stuck releasing treatment according to the stuck point when the torque of the drill is lower.

Can know via foretell technical scheme, compared with the prior art, the utility model discloses a deep high temperature is undervoltage composite drilling device for well, aim at the comprehensive utilization impact, the gyration, three kinds of mode combined action destruction shaft bottom rocks are ruptured to the heat, nearly drill bit decompression nipple joint utilizes venturi effect or vortex suction principle to produce local negative pressure in the annular space passageway of nearly drill bit position, the suction just carries the drilling fluid that returns to ground on the detritus to the shaft bottom after by gathering the nozzle blowout, reduce shaft bottom positive pressure difference, reduce the pressure and hold the effect, improve mechanical drilling speed, prolong the drill bit life-span, increase single trip footage.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required to be used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.

Fig. 1 is a schematic structural diagram of an under-pressure composite drilling device for a deep high-temperature well, provided by the present invention;

FIG. 2 is a sectional view of the connection between the near bit pressure reducing nipple and the bit according to the present invention;

FIG. 3 is a schematic structural diagram of a bottom combined drilling tool for drilling a straight well section according to the present invention;

fig. 4 is a schematic structural diagram of a bottom combined drilling tool during directional drilling according to the present invention;

fig. 5 is a schematic structural diagram of a bottom combined drilling tool during horizontal drilling.

Wherein:

1-a surface drilling section;

11-a drilling machine; 12-a circulation conduit; 13-a drilling fluid cooling system; 14-drilling fluid circulation system;

2-a downhole drilling tool section;

21-a drill rod; 22-drill collar; 23-a power assembly; 231-high temperature resistant hybrid power drill; 232-high temperature resistant MWD; 233-near bit measuring nipple; 234-additional drill rods; 24-near bit relief nipple;

241-an annulus channel; 242-suction flow channel; 243-sand mulling throat; 244-suction flow path; 25-a drill bit;

251-energy concentrating nozzle.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

Referring to fig. 1 and fig. 2, the embodiment of the utility model discloses under-voltage composite drilling device for deep high temperature well, include:

a surface drilling section 1; the ground drilling part 1 comprises a drilling machine 11 and a drilling fluid cooling system 13 connected with the drilling machine 11 through a circulating pipeline 12, wherein the circulating pipeline 12 is also provided with a drilling fluid circulating system 14 in series, and the drilling fluid circulating system 14 is positioned at two sides of the drilling fluid cooling system 13;

a downhole drilling tool section 2; the downhole drilling section 2 comprises a drill pipe 21, the drill pipe 21 is connected with the drilling machine 11 and is communicated with the circulating pipeline 12; the drill collar 22, the power assembly 23, the near-bit pressure reducing nipple 24 and the drill bit 25 are sequentially connected with the drill rod 21; the power assembly 23 is used for providing drilling power or simultaneously carrying out drilling parameter measurement; the near-bit pressure-reducing nipple 24 has an annular passage 241 axially communicating with the drill pipe 21; a plurality of suction flow channels 242 are uniformly arranged in the circumferential direction of the annular channel 241; a sand mixing throat pipe 243 communicated with the suction flow channel 242 is arranged on the outer side wall of the near-bit pressure reducing short section 24 in the circumferential direction; a suction flow passage 244 is further formed in the outer side wall of the near-bit pressure reducing short section 24, and the suction flow passage 244 is communicated with a node of the suction flow passage 242 and the sand mixing throat 243; the forward end of the bit 25 has a shaped nozzle 251, the shaped nozzle 251 communicating with the annular passage 241.

In order to further optimize the technical scheme, the suction flow channel 242 is integrally communicated with the sand mixing throat 243 and obliquely extends from the inner wall of the annular channel 241 to the direction far away from the drill bit 25; the suction flow passage 244 extends obliquely from the outer side wall of the near-bit pressure-reducing sub 24 to a direction away from the bit 25.

Referring to fig. 3, when drilling a straight well section, the power assembly 23 includes a high temperature resistant composite power drill 231 connected to the bottom end of the drill pipe 21, and the high temperature resistant composite power drill 231 is connected to the near-bit pressure reducing nipple 24.

Referring to fig. 4, when the directional drilling is performed, the power assembly 23 includes a high temperature resistant MWD232, a high temperature resistant composite power drilling tool 231, and a near bit measurement sub 233, which are connected to the bottom end of the drill pipe 21 in sequence, and the near bit measurement sub 233 is connected to the near bit pressure reduction sub 24.

Referring to fig. 5, when horizontal section drilling is performed, the power assembly 23 includes an additional drill pipe 234, a high temperature resistant MWD232, a high temperature resistant composite power drilling tool 231, and a near bit measuring sub 233, which are connected to the bottom end of the drill pipe 21 in sequence, and the near bit measuring sub 233 is connected to the near bit pressure reducing sub 24.

In order to further optimize the above technical solution, the drilling fluid cooling system 13 is an air cooling mechanism that uses an axial flow fan to sweep and cool the sprayed drilling fluid, or a liquid cooling mechanism that uses a secondary refrigerant and the drilling fluid to perform non-contact heat exchange and cooling in a convection heat exchanger.

In order to further optimize the above technical solution, the drilling fluid circulation system 14 includes a vibrating screen, a sand remover, a mud remover, a centrifuge, a degasser and a mud pump, and is used for establishing a ground circulation of the drilling fluid to remove rock debris particles in the drilling fluid.

The utility model provides an under-voltage composite drilling technology for deep high temperature well specifically includes following steps:

s1, after the drill bit is drilled to the bottom, a pump is started to drill circularly, the high-pressure drilling fluid drives the power assembly 23 to generate torsion and impact, the drill bit 25 gradually bites into the formation rock under the combined action of the bit pressure and the periodic impact force, and the drill bit 25 rotates to cut off the circumferential rock under the action of the torque of the power assembly 23;

s2, the low-temperature drilling fluid cooled by the drilling fluid cooling system 13 flows downwards to flow through the near-bit pressure reducing nipple 24, most of the drilling fluid continuously flows downwards to flow through the energy-gathering nozzle 251 of the bit 25 and then impacts the rock in a high-speed jet flow mode, and the thermal stress and jet flow impact force generated in the rock by the temperature difference between the high-temperature rock and the low-temperature drilling fluid are utilized to generate micro-cracks in the rock, so that the rock strength is reduced, and the rock is crushed under the action of torsion and impact load; a small amount of drilling fluid generates negative pressure after flowing through the suction flow passage 244, and the drilling fluid returning upwards in the annular passage 241 is sucked through the suction flow passage 242, so that the bottom hole pressure at the drill bit 25 is reduced, and the pressure holding effect is weakened.

In step S1, the drilling pressure is 100-120kN and the displacement is 30L/S during drilling of the hard rock stratum.

During directional drilling and horizontal drilling, the near-bit measuring nipple 233 transmits the measured engineering parameters and logging parameters to the high-temperature-resistant MWD232 through a short transmission system, and the high-temperature-resistant MWD232 packages the measured trajectory parameters, the engineering parameters and the logging parameters together and uploads the packaged trajectory parameters to the ground.

And the ground worker judges whether the target layer can be drilled by continuous drilling according to the logging parameters and the track parameters, and if the target layer cannot be drilled by continuous drilling according to the current scheme or the deviation of the target layer and the original well track is overlarge, the target layer is drilled by sliding directional drilling or an instruction is issued to a rotary steering system for adjustment.

When the measured bit pressure of the drill bit is smaller than the surface apparent bit pressure in the drilling process, the composite drilling torque is low, and the sliding drilling torque is basically unchanged, the pressure supporting condition possibly occurs underground, short-lift operation is carried out, the well wall is pulled and scratched, the detritus bed is damaged, the purification of the drilling fluid is enhanced, and meanwhile, a proper amount of lubricant is added into the drilling fluid; when the torque and the pump pressure suddenly rise during drilling, accidents such as roller cone falling and palm breaking of a drill bit can occur, and then the drill is taken out for inspection; when the torque and the pump pressure are suddenly reduced during drilling, the high-temperature-resistant composite power drilling tool is likely to have the abnormalities such as drilling tool degumming and the like, whether an abnormal object is returned from a vibrating screen in a drilling fluid circulating system or not is observed, and if the abnormal object is returned, the drilling is started for inspection; when the torque is unchanged during drilling and the pump pressure is gradually reduced, the upper drill rod or drill collar is likely to have puncture, and then the drilling is started for inspection; when the drill is stuck, starting the pump for circulation, judging that the stuck point is positioned near the drill when the torque of the drill is larger, and performing stuck releasing treatment according to the stuck point when the torque of the drill is lower.

The utility model provides an under-voltage composite drilling technology for deep high temperature well adopts under-well under-voltage + strike gyration composite drilling new method to carry out the speed-up and creep into, and its theory of operation is:

1) impact and rotation composite rock breaking: the drill bit 25 is periodically applied with vibration impact by the high-temperature resistant composite power drill 231 to form a breaking pit or continuous cracks, the strength of the rock is reduced, and meanwhile, the drill bit 25 is applied with continuous rotary cutting torque to shear and damage the rock at the tooth-entry part, so that three-dimensional gouging type rock breaking is formed.

2) Hydraulic impact rock breaking: the energy-gathering nozzles 251 on the drill bit 25 utilize the Bernoulli principle, the flow velocity of the drilling fluid is increased after the drilling fluid flows through, the kinetic energy is increased, and jet impact damage is formed on the rock at the bottom of the well.

3) Breaking rock by thermal stress: the drilling fluid cooling system 13 is adopted to convey the drilling fluid to the bottom of the hole after cooling through the drill rod 21, exposed rock at the bottom of the hole is cooled, and the thermal stress generated by temperature difference is utilized to enable the hard rock to generate micro-cracks at high temperature, so that the rock strength is reduced.

4) Bottom hole local negative pressure: the near-bit pressure reducing nipple 24 generates local negative pressure in an annular space at the position near the bit by using a Venturi tube effect or a vortex suction principle, and sucks drilling fluid which is just sprayed out from the energy-gathering nozzle 251 and carries rock debris, so that the positive pressure difference at the bottom of a well is reduced.

In the embodiment, the bit 25 may be a roller cone bit or a diamond-impregnated bit in a high-hardness non-uniform stratum, or a PDC bit in a homogeneous stratum; the drill bit 25 is equipped with a shaped jet 251 which can impact the drilling fluid to the bottom of the well at a high speed, and the temperature and pressure of the bottom of the well can be rapidly changed after the drilling fluid enters the bottom of the well.

The near-bit pressure reducing nipple 24 in this embodiment includes, but is not limited to, a jet type and a vortex type, for example, the jet type is taken as an example, as shown in fig. 2, the near-bit pressure reducing nipple 24 is installed above the bit 25, when the drilling fluid flows through the near-bit pressure reducing nipple 24, a part of the drilling fluid is conveyed to the bit 25 to cool the bottom of the well and carry rock debris, and meanwhile, a part of the drilling fluid flows through the suction flow passage 244 to form jet flow, so as to generate negative pressure, so that the drilling fluid in the annular space of the bit is driven to flow in through the suction flow passage 242 and is mixed in the sand mixing throat 243, thereby reducing positive pressure difference at the bottom of the well and weakening the pressure holding effect.

The near bit measurement nipple 233 in this embodiment includes, but is not limited to, engineering parameters and gamma imaging measurement, and its main function is to measure engineering parameters such as bit pressure, torque, rotation speed, internal and external pressure at the position of the downhole bit 25 and formation lithology characteristics, and determine whether the pressure relief and drilling are normal.

The high temperature resistant composite power drilling tool 231 in the embodiment has the temperature resistance of over 180 ℃, the upper part adopts a high temperature resistant screw or turbine motor, the middle part adopts a valve control type or energy storage type impactor, the lower part is a main shaft joint, and a high-strength bearing is arranged in the high temperature resistant composite power drilling tool to bear the drilling pressure and the impact action generated by the impactor.

In the embodiment, the high temperature resistance MWD232 has the temperature resistance higher than 175 ℃, the lower part of the high temperature resistance MWD232 is matched with a near bit measuring short joint 233 (engineering parameters, gamma imaging and the like), the borehole track, the drilling parameters and the stratum type are monitored and measured, the related parameters are uploaded to the ground, and a ground technician timely tracks and adjusts the borehole track as required to drill a target horizon.

The embodiments in the present description are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other. The device disclosed by the embodiment corresponds to the method disclosed by the embodiment, so that the description is simple, and the relevant points can be referred to the method part for description.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (7)

1. The utility model provides a deep portion high temperature is undervoltage composite drilling device for well which characterized in that includes:

a surface drilling section (1); the ground drilling part (1) comprises a drilling machine (11), a drilling fluid cooling system (13) connected with the drilling machine (11) through a circulating pipeline (12), and drilling fluid circulating systems (14) positioned on two sides of the drilling fluid cooling system (13) are further mounted on the circulating pipeline (12) in series;

a downhole drilling tool portion (2); the downhole drilling section (2) comprising a drill rod (21), the drill rod (21) being connected to the drilling machine (11) and communicating with the circulation conduit (12); the drill collar (22), the power assembly (23), the near-bit pressure reducing nipple (24) and the drill bit (25) are sequentially connected with the drill rod (21); the power assembly (23) is used for providing power required by the drill bit to drill and measuring drilling parameters; the near-bit pressure-reducing nipple (24) has an annular passage (241) axially communicating with the drill rod (21); a plurality of suction flow channels (242) are uniformly arranged in the circumferential direction of the annular channel (241); a sand mixing throat pipe (243) communicated with the suction flow channel (242) is arranged on the outer side wall of the near-bit pressure reducing short section (24) in the circumferential direction; a suction flow passage (244) is further formed in the outer side wall of the near-bit pressure reducing short section (24), and the suction flow passage (244) is communicated with the suction flow passage (242) and a node of the sand mixing throat pipe (243); the bit (25) front end has a shaped nozzle (251), the shaped nozzle (251) communicating with the annulus passage (241).

2. The under-pressure composite drilling device for the high-temperature deep well according to claim 1, wherein the suction flow channel (242) is integrally communicated with the sand mulling throat (243) and obliquely extends from the inner wall of the annular channel (241) to the direction away from the drill bit (25); the suction flow channel (244) extends obliquely from the outer side wall of the near-bit pressure reducing short joint (24) to the direction far away from the drill bit (25).

3. The under-pressure composite drilling device for the deep high-temperature well is characterized in that when a vertical well section is drilled, the power assembly (23) comprises a high-temperature-resistant composite power drilling tool (231) connected with the bottom end of the drill rod (21), and the high-temperature-resistant composite power drilling tool (231) is connected with the near-bit pressure reducing short joint (24).

4. The under-pressure composite drilling device for the deep high-temperature well is characterized in that when directional section drilling is carried out, the power assembly (23) comprises a high-temperature-resistant MWD (232), a high-temperature-resistant composite power drilling tool (231) and a near-bit measuring sub (233) which are sequentially connected with the bottom end of the drill rod (21), and the near-bit measuring sub (233) is connected with the near-bit pressure reducing sub (24).

5. The under-pressure composite drilling device for the deep high-temperature well is characterized in that when horizontal section drilling is carried out, the power assembly (23) comprises an additional drill pipe (234), a high-temperature-resistant MWD (232), a high-temperature-resistant composite power drilling tool (231) and a near-bit measuring sub (233) which are sequentially connected with the bottom end of the drill pipe (21), and the near-bit measuring sub (233) is connected with the near-bit pressure reducing sub (24).

6. The under-pressure composite drilling device for the deep high-temperature well according to claim 1, wherein the drilling fluid cooling system (13) is an air cooling mechanism for purging and cooling the sprayed drilling fluid by using an axial flow fan, or a liquid cooling mechanism for performing non-contact heat exchange and cooling in a convection heat exchanger by using a secondary refrigerant and the drilling fluid.

7. The under-pressure composite drilling device for the high-temperature deep well according to claim 1, wherein the drilling fluid circulation system (14) comprises a vibrating screen, a sand remover, a mud remover, a centrifuge, a degasser and a mud pump, and is used for establishing surface circulation of the drilling fluid and removing rock debris particles in the drilling fluid.

Images