CN117846523A - Reverse circulation drilling equipment - Google Patents

Abstract

The invention discloses a reverse circulation drilling device, which comprises: the double-pipe drilling tool is provided with an outer pipe, an inner pipe and a rock breaking tool, wherein the inner pipe is arranged in the outer pipe in a penetrating way, an annular space between the outer pipe and the inner pipe forms a fluid injection channel, a channel of the inner pipe forms a fluid return channel, and the rock breaking tool is internally provided with an injection channel and a suction channel; the plurality of shunt structures are arranged at intervals along the axial direction of the double-pipe drilling tool; wherein, a part of fluid in the fluid injection channel flows into the bottom of the well from the injection channel to form rock breaking fluid, and the rock breaking fluid carries rock debris into the fluid return channel under the suction action of the suction channel; another portion of the fluid in the fluid injection channel can flow from the flow dividing structure into the fluid return channel to form a jet, and the jet can push the fluid in the fluid return channel to return upwards. The invention ensures that rock breaking fluid can smoothly discharge rock debris by utilizing the suction effect of the rock breaking tool and the pushing effect of the diversion structure, and ensures that the circulating flow field stably operates.

Description

Reverse circulation drilling equipment

Technical Field

The invention relates to the technical field of drilling (drilling) engineering, in particular to the technical field of petroleum and natural gas drilling, and also to the technical field of geotechnical drilling such as geological mineral products, mine rescue and the like, in particular to reverse circulation drilling equipment.

Background

With further emphasis on energy safety, the number of unconventional oil and gas resource exploration and deep and ultra-deep wells is increasing. On one hand, the surface well bore is bigger and deeper; on the other hand, the leakage of formation fluids may cause different levels of environmental pollution, and may increase the drilling cycle due to other complications associated with lost circulation. This not only results in higher overall costs for surface drilling, but also results in non-negligible environmental issues in certain areas. Reverse circulation drilling has therefore been the focus of effort and popularization in the industry. In addition, the unconventional oil and gas exploration and development force is continuously increased, the benefit development requirements are continuously improved, the number of horizontal wells and the length of horizontal sections are obviously increased, and the problems of narrow pressure windows and well hole purification in the well drilling process of the horizontal wells are more and more prominent. The reverse circulation drilling is carried out by using the double-pipe drilling tool (also called as double-wall drilling tool), the circulation medium circulates in the pipe of the drilling tool, the fluctuation of the ECD (Equivalent Circulating Density) at the bottom of the well and the equivalent circulation density of the drilling fluid can be effectively avoided, the stability of the annular pressure gradient is maintained, the rock carrying capacity of the circulation medium is improved, and the drilling of a narrow-density window and the extension of the length of a horizontal section are facilitated.

The gas drilling technology can greatly improve the mechanical drilling speed of hard-to-drill strata such as volcanic rock, gravel layer, clastic rock, carbonate rock and the like, and for example, when the gas drilling technology is applied to some areas, the average drilling speed can be improved by 4-15 times. However, when the positive circulation gas is used for drilling (particularly a large-diameter well), equipment investment is large, occupied space is large, gas consumption is large, operation energy consumption is high, cost is high, for example, the gas required for gas drilling in a well with a depth of less than 500m and a diameter of 26 inches is 300m ³ /min～450m ³ Per min, 180m gas demand for gas drilling in a wellbore having a depth of 500m to 1000m and a diameter of 17.5 inches ³ /min～250m ³ Per min, 200m gas demand for gas drilling in a wellbore of diameter 17.5 inches and depth 1000m to 2000m ³ /min～300m ³ A/min; under the condition of poor stability of the well wall or large water yield of the stratum, the gas drilling is carried out by increasing the gas amount, so that erosion of the well wall is aggravated, and the possibility of instability of the well wall is increased; meanwhile, the capability of treating the stratum water outlet problem is poor, if stratum cracks develop at the same time (namely, lost circulation is lost and a large amount of stratum water is discharged), normal circulation is difficult to establish, even if gas-filled drilling is adopted, water leakage and sand leakage are easy to occur, and underground safety is difficult to ensure; these problems impose a number of limitations on the application of positive cycle gas drilling.

The reverse circulation drilling technology can effectively solve the problems, and is a focus of the industry for attack and popularization. However, the prior reverse circulation drilling technology has the technical problems that: (1) The gas lift reverse circulation has high requirement on the liquid level of the well bore annulus, has low drilling efficiency, and cannot be used for drilling leakage stratum such as fracture stratum, easily eroded stratum and the like; (2) Other related reverse circulation technologies are used for sealing the well space and injecting fluid (gas or liquid), on one hand, the method can only be used for stabilizing the stratum, otherwise, once the stratum is blocked, the drilling is easy to be blocked; on the other hand, the capacity of treating leakage is very limited, and the capacity of treating malignant leakage is even more unavailable.

Disclosure of Invention

The invention aims to provide reverse circulation drilling equipment to solve the technical problems that the existing reverse circulation drilling technology is low in drilling efficiency, deep wells are difficult to build circulation, cannot cope with malignant leakage stratum, are not suitable for unstable stratum and are easy to seize.

The above object of the present invention can be achieved by the following technical solutions:

the invention provides a reverse circulation drilling device, comprising: the double-pipe drilling tool is provided with an outer pipe, an inner pipe and a rock breaking tool, wherein the inner pipe is arranged in the outer pipe in a penetrating manner, an annular space between the outer pipe and the inner pipe forms a fluid injection channel, a channel of the inner pipe forms a fluid return channel, the rock breaking tool is internally provided with an injection channel and a suction channel, the injection channel is communicated with the fluid injection channel, and the suction channel is communicated with the fluid return channel; the plurality of shunt structures are arranged at intervals along the axial direction of the double-pipe drilling tool; wherein, a part of fluid in the fluid injection channel flows into the bottom of the well from the injection channel to form rock breaking fluid, and the rock breaking fluid carries rock debris into the fluid return channel under the suction action of the suction channel; another portion of the fluid in the fluid injection channel can flow from the flow dividing structure into the fluid return channel to form a jet, and the jet can push the fluid in the fluid return channel to return upwards.

In an embodiment of the invention, the flow dividing structure is provided with a plurality of flow dividing holes, the plurality of flow dividing holes are arranged at intervals along the circumferential direction of the double-pipe drilling tool, the flow dividing holes are communicated with the fluid injection channel and the fluid return channel, and the flow direction of fluid in the flow dividing holes is inclined upwards.

In an embodiment of the invention, the double-pipe drilling tool comprises at least one upper drilling tool and at least one lower drilling tool, the flow distribution structure comprises a flow distribution nipple, the flow distribution nipple comprises an outer nipple and an inner nipple, an outer pipe of the upper drilling tool is communicated with an outer pipe of the lower drilling tool through the outer nipple, an inner pipe of the upper drilling tool is communicated with an inner pipe of the lower drilling tool through the inner nipple, and the flow distribution hole is arranged on the inner nipple.

In the embodiment of the invention, the double-pipe drilling tool is provided with a packer while drilling; in a drilling state, the packer while drilling device can expand outwards to seal a shaft annulus between the double-pipe drilling tool and the shaft; in the drilling state, the while-drilling packer device can retract inwards to be smaller than the radial dimension of the shaft.

In the embodiment of the invention, at least one centralizer is also arranged on the double-pipe drilling tool, the centralizer is arranged close to a wellhead relative to the packer while drilling, and in a drilling state, the centralizer can expand outwards to centralize the double-pipe drilling tool; in the lifted state, the centralizer is also retractable inward to less than the radial dimension of the wellbore.

In an embodiment of the invention, the rock breaking tool comprises an anti-seize drill bit, and in a drilling state, the anti-seize drill bit can expand outwards to drill; in the drill lifting state, the anti-seize drill bit can also retract inwards to be smaller than the radial dimension of the shaft.

In the embodiment of the invention, the double-pipe drilling tool is provided with the anti-blocking counter-impact device and the floating counter-impact drill bit, and the anti-blocking counter-impact device and the floating counter-impact drill bit are sequentially arranged above the while-drilling packing device from bottom to top; in the state that the double-pipe drilling tool lifts the drill and meets resistance, the impact piston in the anti-blocking impact device can impact the floating impact drill bit upwards so that the floating impact drill bit impacts the drill upwards.

In an embodiment of the invention, one end of the double-pipe drilling tool, which is positioned above the ground, is provided with a fluid injection and discharge mechanism, the fluid injection and discharge mechanism comprises an injection structure, a rotary injection and discharge adapter and a discharge pipeline, the injection structure is communicated with the fluid injection channel through a flow distribution channel of the rotary injection and discharge adapter, and the discharge pipeline is communicated with the fluid return channel through a return channel of the rotary injection and discharge adapter.

In the embodiment of the invention, a plurality of drainage assisting structures are arranged on the drainage pipeline at intervals along the axial direction of the drainage pipeline, the drainage assisting structures can inject drainage assisting fluid into the drainage pipeline and form drainage assisting jet flow, and the drainage assisting jet flow can push the fluid in the drainage pipeline to be discharged.

In an embodiment of the present invention, the rotary injection and discharge adapter is mounted at an end of the double-pipe drilling tool above the ground through a reverse circulation damper, and is in communication with the fluid injection passage and the fluid return passage.

In an embodiment of the present invention, the inner pipe has a conductive structure thereon, and the dual pipe drilling tool performs power transmission and signal transmission through the conductive structure.

In an embodiment of the invention, the inner pipe comprises a plurality of inner pipe joints, the conductive structure comprises a conductive layer, the conductive layer is coated on the outer wall surface of the inner pipe joints, the conductive layer is arranged on the outer wall surface of the inner pipe joints, two adjacent inner pipe joints are connected in a matched manner through an inner pipe male connector and an inner pipe female connector, at least one conducting wire is embedded in each of the inner pipe male connector and the inner pipe female connector, at least one group of matched conductive contact structures are arranged on the contact surfaces of the inner pipe male connector and the inner pipe female connector, and the conductive contact structures are communicated with the corresponding conductive layers through the corresponding conducting wires.

The invention has the characteristics and advantages that:

according to the reverse circulation drilling equipment, the plurality of diversion structures are additionally arranged on the double-pipe drilling tool, so that a part of fluid in the fluid injection channel can flow into the fluid return channel to form jet flow, and rock breaking fluid at the bottom of a shaft can be pushed by the jet flow in the process that the rock breaking fluid enters the fluid return channel and is conveyed upwards under the suction effect of the fluid return channel, so that the rock breaking fluid can be smoothly discharged with the rock breaking fluid, and the running stability of a circulation flow field is improved.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for the description of the embodiments will be briefly described below, and it is apparent that the drawings in the following description are only some embodiments of the present invention, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic structural view of the reverse circulation drilling apparatus of the present invention in a drill lifting state.

Fig. 2 is an enlarged view of a portion of the reverse circulation drilling apparatus of the present invention in a pulled-up condition.

Fig. 3 is a schematic view of the reverse circulation drilling apparatus of the present invention in a drilling state.

Fig. 4 is an enlarged view of a portion of the reverse circulation drilling apparatus of the present invention in a drilling state.

Fig. 5 is a schematic structural diagram of flow field regulation by using a flow dividing structure.

FIG. 6 is a schematic diagram of the structure of the present invention for forced reverse circulation in combination with a packer while drilling.

FIG. 7 is a schematic illustration of a packing element of a first embodiment of the present invention.

FIG. 8 is a schematic illustration of a packing element of a second embodiment of the present invention.

FIG. 9 is a schematic view of a packing element packer according to a third embodiment of the invention.

Fig. 10 is a cross-sectional view of a packing element in a third embodiment of the present invention.

FIG. 11 is a partial cross-sectional view of the packer while drilling apparatus of the invention in a drill-up condition.

Fig. 12 is an enlarged view of the upper portion of the packer while drilling apparatus of the invention in a drill-up condition.

Fig. 13 is an enlarged view of the lower portion of the packer while drilling apparatus of the invention in a drill-up condition.

Fig. 14 is a schematic structural view of a fluid injecting and discharging mechanism and a discharging assisting structure according to the present invention.

Fig. 15 is a schematic structural view of the dual pipe drilling tool of the present invention for reverse circulation drilling.

Fig. 16 is a schematic view of the structure of the double-pipe drilling tool for forward circulation drilling according to the present invention.

In the figure:

1. double-pipe drilling tool; 101. an inner tube; 102. an inner pipe section; 103. a conductive layer; 104. an inner pipe female joint; 105. an inner tube male connector; 106. a conductive contact structure; 106', conductive contact structures; 107. a wire; 107', wires; 108. a seal ring; 109. an outer tube; 110. an outer pipe joint; 111. an outer tube female joint; 112. an outer tube male connector; 113. a fluid injection channel; 114. a fluid return channel; 115. anti-seize drill bit; 116. a reverse circulation air hammer; 117. drilling tool; 117', drilling tool; 118. a rock breaking tool; 119. a jet channel; 120. a suction channel; 121. a conductive structure;

2. A shunt structure; 201. a shunt nipple; 202. an inner nipple; 203. an outer nipple; 204. a diversion aperture;

3. a packer while drilling; 301. a rubber sleeve packer; 302. a cartridge holder; 302', a rubber cylinder seat; 303. a mounting ring; 304. a limit sleeve; 305. a baffle ring; 306. a slot; 307. a mounting hole; 308. a mounting surface; 309. a rubber cylinder; 310. a hollow cavity; 311. a protrusion; 312. an outer wall surface; 313. an inner wall surface; 314. a skeleton; 315. two connecting rods; 316. a connecting rod; 317. a pin shaft; 318. a convex curved surface; 319. a support sheet; 320. a convex curved surface; 321. a support wire; 322. a convex curved surface; 323. a compressible stroke; 324. a rubber cylinder seat positioning pin; 324', a rubber cylinder seat positioning pin; 325. connecting sleeves; 326. an upper transmission structure; 327. a spline housing; 328. an upper limit step surface; 329. a double female joint; 330. an upper joint; 331. a lower transmission structure; 332. a spline shaft; 333. a lower limit step surface; 334. an adjustment pad; 335. a clasp; 335', snap ring; 336. an upper rotating structure; 337. an upper bearing sleeve; 338. an upper bearing sleeve locking ring; 339. an upper bearing; 340. an upper limit ring; 341. a lower rotating structure; 342. a lower bearing sleeve; 343. a lower bearing sleeve snap ring; 344. a lower bearing; 344', lower bearings; 345. a lower limit ring; 346. a core tube is arranged; 347. a lower core tube;

4. A centralizer; 5. an anti-seize impact device; 6. floating counterattack bit; 7. a fluid injection and discharge mechanism; 701. an injection structure; 702. rotating the injection row adapter; 703. a discharge pipe; 704. a reverse circulation damper; 705. a gooseneck; 706. a flow distribution channel; 707. a return flow channel; 8. an auxiliary drainage structure; 801. drainage-assisting jet holes; 802. an auxiliary drainage pipeline;

9. a wellbore; 901. a wellbore annulus; 902. a wellhead; 903. a well bottom; 904. stabilizing the formation; 905. a fracture formation; 906. the stratum is easy to erode; 907. a station.

Detailed Description

The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

As shown in fig. 1, 3 and 5, the present invention provides a reverse circulation drilling apparatus, a double-pipe drilling tool 1, which comprises an outer pipe 109, an inner pipe 101 and a rock breaking tool 118, wherein the inner pipe 101 is arranged in the outer pipe 109 in a penetrating manner, an annular space between the outer pipe 109 and the inner pipe 101 forms a fluid injection channel 113, a channel of the inner pipe 101 forms a fluid return channel 114, an injection channel 119 and a suction channel 120 are arranged in the rock breaking tool 118, the injection channel 119 is communicated with the fluid injection channel 113, and the suction channel 120 is communicated with the fluid return channel 114; the plurality of shunt structures 2 are arranged at intervals along the axial direction of the double-pipe drilling tool 1; wherein a portion of the fluid in the fluid injection channel 113 flows from the injection channel 119 into the bottom 903 to form a rock breaking fluid, which carries cuttings into the fluid return channel 114 under the suction action of the suction channel 120; another portion of the fluid in the fluid injection channel 113 can flow from the shunt structure 2 into the fluid return channel 114 to form a jet, which can push the fluid in the fluid return channel 114 back up.

According to the reverse circulation drilling equipment, the plurality of diversion structures 2 are additionally arranged on the double-pipe drilling tool 1, so that a part of fluid in the fluid injection channel 113 can flow into the fluid return channel 114 and form jet flow, and rock breaking fluid at the bottom of the shaft 9 can be pushed by the jet flow in the process that the rock breaking fluid enters the fluid return channel 114 and is conveyed upwards under the suction effect of the fluid return channel 114, so that the rock breaking fluid can be smoothly discharged with the rock breaking fluid, and the stability of reverse circulation operation is improved.

Above the wellhead 902 a platform 907 is set up, through which platform 907 the double pipe drilling tool 1 drills. The fluid injection device injects fluid with pressure into the fluid injection channel 113, so that a part of the fluid in the fluid injection channel 113 flows into the fluid return channel 114 through the diversion structure 2 to form a jet with a certain driving force, and the other part of the fluid in the fluid injection channel 113 is injected from the injection channel 119 of the rock breaking tool 118 to the bottom 903 of the well to form rock breaking fluid; the rock breaking tool 118 includes, but is not limited to, a reverse circulation bit, a reverse circulation roller cone bit, and a reverse circulation PDC bit, which themselves have negative pressure pumping capability so as to pump the breaking fluid at the bottom of the well 903 from the pumping channel 120 to the fluid return channel 114; therefore, the invention can realize self-priming upward return of the whole well section by the suction of the fluid participating in rock breaking at the bottom of the well 903 and pushing of the upper flow structure 2, ensure that the fluid can smoothly return from the fluid return channel 114 of the double-pipe drilling tool 1 with rock fragments, thereby improving the drilling efficiency, and is also applicable to the leakage stratum such as the fracture stratum 905, the easily-eroded stratum 906 and the like. In addition, with the reverse circulation drilling apparatus of the present invention, it is generally possible to avoid leakage of the rock breaking fluid into the well bore annulus 901, and even if the rock breaking fluid leaks into the well bore annulus 901, only a small amount of the rock breaking fluid leaks into the well bore annulus 901, and the pumping channel 120 of the rock breaking tool 118 can pump the rock breaking fluid leaking into the well bore annulus 901 to the fluid return channel 114 together due to the stable operation of the circulation flow field.

In particular, the fluid can be gas or liquid, preferably liquid, with better effect. The number and installation location of the shunt structure 2 is selected according to the depth of the wellbore 9. The flow dividing structure 2 can be provided with two, three or more flow dividing structures 2 which are arranged at intervals along the axial direction of the double-pipe drilling tool 1, and the jet flow formed by the flow dividing structures 2 pushes the fluid in the fluid return channel 114 in a relay mode, so that the fluid can be ensured to return to the ground from the fluid return channel 114, and the leakage of the fluid to the well bore annulus 901 between the double-pipe drilling tool 1 and the well bore 9 is avoided, so that the circulation cannot be effectively established or interrupted.

As shown in fig. 5, in the embodiment of the present invention, the diversion structure 2 has a plurality of diversion holes 204, the plurality of diversion holes 204 are arranged at intervals along the circumferential direction of the double-pipe drilling tool 1, the diversion holes 204 are communicated with the fluid injection channel 113 and the fluid return channel 114, and the flow direction of the fluid in the diversion holes 204 is inclined upwards. By providing the diverter aperture 204 at an incline such that the angle between the direction of flow of the jet and the direction of flow of the fluid in the fluid return channel 114 is less than 90 degrees, the fluid in the fluid return channel 114 is better forced to flow upward. Specifically, the number of the diversion holes 204 and the aperture of the diversion holes 204 in the diversion structure 2 are designed according to the flow regulation requirement and the pressure regulation requirement of the jet flow. As the double pipe drilling tool 1 is continuously drilled, the well bore is continuously deepened, and the depth position of the shunt structure 2 is also continuously changed.

As shown in fig. 1 and 3, in the present embodiment, the number of the shunt structures 2 is three. Specifically, the rock breaking tool 118 pumps the rock breaking fluid at the bottom 903 from the pumping channel 120 to the fluid upward return channel and returns to the position of the diversion structure 2 closest to the rock breaking tool 118, and then continues to return to the middle diversion structure 2 under the pushing of the jet flow at the first diversion structure 2, then continues to return to the uppermost diversion structure 2 under the pushing of the jet flow at the diversion structure 2, and finally continues to return to the top under the pushing of the jet flow at the diversion structure 2 and then is discharged.

The double-pipe drilling tool 1 comprises at least one upper drilling tool and at least one lower drilling tool, the flow distribution structure 2 comprises a flow distribution nipple 201, the flow distribution nipple 201 comprises an outer nipple 203 and an inner nipple 202, an outer pipe of the upper drilling tool is communicated with an outer pipe of the lower drilling tool through the outer nipple 203, an inner pipe of the upper drilling tool is communicated with an inner pipe of the lower drilling tool through the inner nipple 202, and a flow distribution hole 204 is formed in the inner nipple 202. Shunt through setting up reposition of redundant personnel nipple 201, simple structure, and be convenient for dismouting.

The upper and lower tools described in the present invention are not referred to as tools at a specific location, but for convenience of description, the tool 117' connected to the end of the diverting structure 2 near the wellhead 902 is referred to as an upper tool, and the tool 117 connected to the end of the diverting structure 2 near the bottom 903 is referred to as a lower tool. The upper drill may include a drill pipe tool, the lower drill may include a drill pipe tool, and may include a rock breaking tool 118.

The invention utilizes the diversion structure 2 to regulate and control the circulating flow field, and can establish a stable circulating flow field without sealing the position of the shaft annulus 901 close to the rock breaking tool 118 or sealing the well head 902, but in order to further improve the stability of the circulating flow field, the invention can also seal the position of the shaft annulus 901 close to the rock breaking tool 118 and/or seal the well head 902.

As shown in fig. 2, 4 and 6, in the embodiment of the present invention, at least one packer while drilling device 3 is mounted on the double-pipe drilling tool 1; in the drilling state, the packer while drilling device 3 can expand outwards to seal the well bore annulus 901; in the lifted state, the while-drilling packer 3 is able to retract inwardly to less than the radial dimension of the wellbore 9. When the double-pipe drilling tool 1 drills, the well bore annulus 901 is sealed by the while-drilling sealing device 3, so that forced circulation is realized, and further, the circulated fluid is ensured to smoothly carry rock fragments out of the fluid return channel 114, and continuous drilling is facilitated. Specifically, when the periphery of the well bore 9 is provided with the fracture formation 905 and/or the erosion-prone formation 906 and other leakage-prone formations, the well bore annulus 901 is sealed by the while-drilling sealing device 3 being attached to the fracture formation 905 and/or the stable formation 904 below the erosion-prone formation 906, so that the circulation flow field is not influenced by the fracture formation 905 and/or the erosion-prone formation 906.

As shown in fig. 7, 8 and 9, the packer while drilling device 3 of the present invention comprises at least one rubber packer 301, the rubber packer 301 comprising: two rubber cylinder bases 302 are arranged opposite to each other and at intervals; the two ends of the rubber cylinder 309 are connected with two rubber cylinder seats 302, and the rubber cylinder 309 can deform under the extrusion state; the two ends of the framework 314 are connected with the two rubber cylinder seats 302 and are positioned in the rubber cylinder 309, and the radial dimension of the two ends of the framework 314 is smaller than the radial dimension of the middle part of the framework 314 to form a first expansion shape; the frame 314 is capable of expanding from a first expanded configuration to a second expanded configuration in a state where the two cartridge holders 302 are close to each other, supporting the cartridge 309 to guide the cartridge 309 to expand and deform outwards, and is capable of retracting from the second expanded configuration to the first expanded configuration in a state where the two cartridge holders 302 are far away from each other.

According to the rubber packer 301 disclosed by the invention, the framework 314 is additionally arranged in the rubber sleeve 309, two ends of the framework 314 are connected with the two rubber sleeve bases 302, in a state that the distance between the two rubber sleeve bases 302 is unchanged, namely, the rubber sleeve packer 301 is in a free state, the framework 314 forms a first expansion state with small two ends and large middle part, so that the two rubber sleeve bases 302 are close to each other, namely, the rubber sleeve packer 301 is in an axially extruded state, the rubber sleeve 309 can be guided to be outwards expanded in the process that the framework 314 is outwards expanded from the first expansion state to form a second expansion state, and therefore, the problem that the rubber sleeve 309 is inwards contracted or otherwise uncontrollably deformed in the axially extruded state of the rubber sleeve packer 301 to prevent sealing can be achieved is avoided, in a state that the two rubber sleeve bases 302 are far away from each other, namely, in a state that the axial extrusion of the rubber sleeve packer 301 is reduced, the framework 314 is inwards contracted from the second expansion state to form the first expansion state, so that the risk of sticking of the rubber sleeve packer is not easy to occur, in addition, the rubber sleeve 309 can be supported by the framework 314, and the stability of the rubber sleeve 301 can be improved when the rubber sleeve 309 is sealed.

Specifically, the two rubber cylinder seats 302 are of a rigid structure, and the distance between the two rubber cylinder seats 302 forms the compressible stroke 323 of the rubber cylinder packer 301, so that the compressible stroke 323 of the rubber cylinder packer 301 can be adjusted by designing the distance between the two rubber cylinder seats 302 of the rubber cylinder packer 301 in a free state, and the outward expansion range of the rubber cylinder 309 can be controlled. In the free state of the packing 301, the packing 309 is substantially cylindrical. The radial dimension of backbone 314 in the first expanded configuration (i.e., the radial dimension at the location of the maximum radial dimension of the middle) is less than the radial dimension of the barrel 309 in the free state. The framework 314 may support the glue cylinder 309 from the first expanded configuration, or may support the glue cylinder 309 after a certain degree of outward expansion. Preferably, the position of maximum radial dimension of the scaffold 314 in the first expanded configuration is located at the midpoint of the scaffold 314 in the axial direction. In addition, a plurality of protrusions 311 may be provided on the outer wall surface 312 of the barrel 309 to enable closer engagement with the borehole wall.

In an embodiment of the present invention, as shown in fig. 7, the expansion and retraction of the frame 314 is accomplished by rotational translation of the linkage structure; or as shown in fig. 8 and 9, the armature 314 may be expanded and retracted by elastic deformation. As shown in fig. 7 and 8, backbone 314 may be mounted within hollow cavity 310 of glue cylinder 309, facilitating installation; as shown in fig. 9, the frame 314 may be embedded in the wall of the rubber cylinder 309, so that the rubber cylinder 309 can be supported more uniformly. Specifically, framework 314 is generally a cage-like structure.

As shown in FIG. 7, in the first embodiment, a backbone 314 is mounted within the hollow cavity 310 of the barrel 309. The framework 314 comprises a plurality of two connecting rods 315, the two connecting rods 315 are uniformly arranged at intervals along the circumferential direction of the rubber cylinder 309, the two connecting rods 315 comprise two connecting rods 316, the connecting rods 316 are provided with opposite first ends and second ends, the first ends of the two connecting rods 316 are hinged through a pin shaft 317, and the second ends of the two connecting rods 316 are connected with the two rubber cylinder seats 302; wherein, the connecting rods 316 of a plurality of two connecting rods 315 can rotate around the pin shafts 317 to expand and retract the framework 314. Specifically, the two connecting rods 316 rotate around the pin shafts 317 toward the inner side of the rubber cylinder 309, and the pin shafts 317 move outwards along the radial direction of the rubber cylinder 309, so that the expansion of the framework 314 is realized; the two links 316 rotate about the pins 317 toward the outside of the barrel 309 while the pins 317 move radially inward of the barrel 309, thereby effecting retraction of the backbone 314. Specifically, the lengths of the two links 316 are the same. The second ends of the two connecting rods 316 may be hinged to the two rubber holders 302, or may abut against the two rubber holders 302. The cartridge seat 302 has a mounting surface 308 connected to a second end of the link 316, and the plurality of two links 315 are prevented from rotating due to the spacing between the mounting surfaces 308 of the two cartridge seats 302 in the free state, thereby forming the frame 314 into a first expanded configuration.

As shown in fig. 7, the first end of the link 316 is curved toward the inside of the cylinder 309, and the curved convex surface 318 is disposed toward the inner wall surface 313 of the cylinder 309. The first end of the two hinged connecting rods 316 is the position with the largest radial dimension of the framework 314, namely the position for supporting the rubber cylinder 309, and the position is bent towards the inner side of the rubber cylinder 309, so that the rubber cylinder 309 is supported by the convex curved surface 318 formed by bending, the rubber cylinder 309 is prevented from being damaged due to the fact that the supporting force provided by the framework 314 is concentrated in the part of the rubber cylinder 309 in the process of guiding the rubber cylinder 309 to expand outwards, and meanwhile, the rubber cylinder 309 is more uniformly stressed and is tightly attached to the shaft 9. The curved shape of the connecting rod 316 is not particularly limited, and may be designed according to the expanded shape of the rubber cylinder 309 so that the expanded shape of the skeleton 314 is as similar as possible to the expanded shape of the rubber cylinder 309.

In a second embodiment, as shown in fig. 8, a backbone 314 is mounted within a hollow cavity 310 of a glue cylinder 309. The framework 314 comprises a plurality of support plates 319, the support plates 319 are integrally and curvedly arranged, a convex curved surface 320 formed by bending is attached to the inner wall surface 313 of the rubber cylinder 309, the plurality of support plates 319 are uniformly distributed at intervals along the circumferential direction of the rubber cylinder 309, and two ends of the support plates 319 are connected with the two rubber cylinder seats 302; wherein the plurality of support sheets 319 are capable of elastically deforming to allow for expansion and retraction of the frame 314. Specifically, the support piece 319 is formed by pre-bending a steel sheet, and is generally "(" shaped, "so that the support piece 319 has a certain supporting force and a certain elastic deformation capability, and the framework 314 can maintain the first expanded configuration in a free state.

As shown in fig. 9 and 10, in the third embodiment, the frame 314 is embedded in the wall of the rubber cylinder 309. The framework 314 comprises a plurality of supporting wires 321, the supporting wires 321 are integrally and curvedly arranged, a convex curved surface 322 formed by bending is arranged towards the outer wall surface 312 of the rubber cylinder 309, the plurality of supporting wires 321 are uniformly distributed at intervals along the circumferential direction of the rubber cylinder 309, and two ends of the supporting wires 321 penetrate through two ends of the rubber cylinder 309 to be connected with two rubber cylinder seats 302; wherein the plurality of support wires 321 are capable of elastically deforming to expand and retract the frame 314. Specifically, support wires 321 are pre-bent from steel wires and are generally "(" shaped so that backbone 314 maintains a first expanded configuration in a free state.

As shown in fig. 7, 8 and 9, the skeleton 314 of the first embodiment is most simply installed and provides the greatest supporting force as compared to the second and third embodiments. Compared with the first embodiment and the third embodiment, the framework 314 of the second embodiment can better fit with the inner wall surface 313 of the rubber cylinder 309, and the supporting force is more uniform. In the third embodiment, compared with the first embodiment and the second embodiment, the frame 314 formed by the supporting wires 321 is not damaged during the process of expanding from the first expanded configuration to the second expanded configuration, so that the frame can be directly embedded in the wall of the rubber 309.

As shown in fig. 7, the cartridge holder 302 may be an integrally formed structure. As shown in fig. 8 and 9, the rubber cylinder base 302 may be assembled in a split structure. Specifically, the rubber cylinder base 302 includes a mounting ring 303, a baffle ring 305, and a stop collar 304. Two ends of the rubber cylinder 309 are connected with the mounting rings 303 of the two rubber cylinder bases 302. The stop collar 304 is mounted in the mounting ring 303 by a stop collar 305 and is located inside the backbone 314. The spacing between the stop collars 304 of the two packing element seats 302 constitutes the compressible stroke 323 of the packing element packer 301. Both ends of the skeleton 314 may be connected to the outer wall surfaces of the two stop collars 304, may be connected to the mounting ring 303, or may be connected to other parts of the rubber cylinder base 302.

As shown in fig. 7, the cartridge holder 302 is provided with a mounting hole 307 and a slot 306, the slot 306 is used for inserting other structures, the mounting hole 307 is used for penetrating a cartridge holder positioning pin, and the cartridge holder 302 is connected with other structures through the cartridge holder positioning pin.

As shown in fig. 6 and 11, the packer while drilling device 3 further includes: an upper drive structure 326 connecting the upper drill 117 'with the uppermost packing element seat 302'; a lower transmission structure 331 connecting the lower drilling tool 117 and the lowermost rubber seat 302, the lower transmission structure 331 being connected to the upper transmission structure 326 and being movable relative to each other in the axial direction of the wellbore 9; in the drilling state, the upper transmission structure 326 moves downwards along the axial direction of the shaft 9 relative to the lower transmission structure 331, and drives the upper rubber cylinder seat 302' to approach the lower rubber cylinder seat 302; in the drill-up condition, the upper transmission structure 326 moves upwardly relative to the lower transmission structure 331 along the axis of the wellbore 9, with the upper cartridge seat 302' being remote from the lower cartridge seat 302.

As shown in fig. 11, 12 and 13, the packer while drilling device 3 further includes: an upper core tube 346 having an upper end penetrating the upper transmission structure 326 and communicating with the inner tube of the upper drill 117'; a lower core tube 347, the lower end of which is disposed through the lower transmission structure 331 and communicates with the inner tube of the lower drill 117, and the lower end of the upper core tube 346 is in sliding engagement with the upper end of the lower core tube 347 in an axial seal of the well bore 9.

Referring to fig. 1 and 3, for convenience of description, the structure of the packer while drilling device 3 is described with reference to the use state of the packer while drilling device 3 in a vertical well, and the upper direction is the direction close to the wellhead 902, and the lower direction is the direction close to the bottom 903, so that the packer while drilling device 3 of the present invention is also suitable for horizontal wells or other wells.

As shown in fig. 6 and 11, the packer while drilling device 3 of the present invention transfers the torque and the weight provided by the upper drilling tool 117' to the lower drilling tool 117 through the upper transmission structure 326 and the lower transmission structure 331, so that in the drilling state, the rubber cylinder seat 302' and the rubber cylinder seat 302 on the packer while drilling device 3 can be pressed between the upper transmission structure 326 and the lower transmission structure 331 to approach each other, so that the rubber cylinder 309 is expanded outwards to seal the annular space 901 of the well bore, and in the drilling state, the upper transmission structure 326 can drive the upper rubber cylinder seat 302' to be far away from the lower rubber cylinder seat 302, so that the rubber cylinder 309 is retracted inwards to be separated from the well bore 9.

Specifically, the upper transmission structure 326 and the lower transmission structure 331 are matched to be similar to a telescopic transmission shaft structure, so that the upper transmission structure can be telescopic along the axial direction of the upper transmission structure and can also transmit torque. In this embodiment, the upper and lower drive structures 326 and 331 are axially telescoping and torque transmitting via a spline connection. The lower transmission structure 331 includes a spline shaft 332, the upper transmission structure 326 includes a spline housing 327, the lower end of the spline shaft 332 is connected to the lower drilling tool 117, and the upper end of the spline shaft 332 is inserted into the spline housing 327 through the at least one rubber packer 301 and is spline-coupled to the spline housing 327 in the axial direction of the wellbore 9. Other suitable telescoping drive shaft configurations in the prior art may also be selected based on torque transfer requirements. In this embodiment, the lower drilling tool 117 connected to the lower transmission structure 331 includes a reverse air hammer 116 and an anti-seize drill bit 115 connected in sequence from top to bottom.

As shown in fig. 6 and 7, in the embodiment of the present invention, the uppermost rubber seat 302' is rotatably connected to the upper transmission structure 326 through the upper rotation structure 336, and the lowermost rubber seat 302 is rotatably connected to the lower transmission structure 331 through the lower rotation structure 341. By arranging the upper rotating structure 336 and the lower rotating structure 341, the rubber sleeve packer 301 cannot rotate along with the rotation of the upper transmission structure 326 and the lower transmission structure 331 when the double-pipe drilling tool 1 drills, so that the rubber sleeve 309 can be attached to the shaft 9 in a relatively static state, and the rubber sleeve 309 and the shaft 9 are prevented from being worn out due to the relative rotation in the circumferential direction. The appropriate upper rotating structure 336 is selected according to the installation space between the upper transmission structure 326 and the uppermost packing element seat 302', and the appropriate lower rotating structure 341 is selected according to the installation space between the lower transmission structure 331 and the lowermost packing element seat 302.

As shown in fig. 12, the upper rotating structure 336 includes an upper bearing sleeve 337, an upper bearing sleeve locking ring 338 and at least one upper bearing 339, the upper bearing sleeve 337 is connected with the uppermost rubber sleeve seat 302' and is rotatably connected with the upper transmitting structure 326 through the upper bearing sleeve locking ring 338 and the upper bearing 339. Specifically, the lower end of the upper bearing sleeve 337 is inserted into the upper end of the uppermost rubber seat 302' and is connected by the rubber seat positioning pin 324 arranged along the radial direction of the well bore 9. The upper end of the upper bearing sleeve 337 is sleeved on the spline sleeve 327 and is sealed by a sealing ring. The upper bearing sleeve locking ring 338 is in threaded connection with the lower end of the spline sleeve 327, and the upper bearing sleeve 337 is in rotational fit with the upper bearing sleeve locking ring 338. An upper limit ring 340 is arranged on the inner wall surface of the upper bearing sleeve 337, the upper limit ring 340 and the spline sleeve 327 are matched to form an upper bearing groove, and sliding friction between the upper bearing sleeve 337 and the upper bearing sleeve locking ring 338 can be reduced by installing an upper bearing 339 in the upper bearing groove. In this embodiment, the number of upper bearings 339 is one.

As shown in fig. 13, the lower rotating structure 341 includes a lower bearing sleeve 342, a lower bearing sleeve snap ring 343 and at least a lower bearing 344, the lower bearing sleeve 342 is connected with the lowermost rubber sleeve seat 302 and is rotationally connected with the lower transmission structure 331 through the lower bearing 344, the lower bearing sleeve snap ring 343 is mounted on the lower transmission structure 331, and the lower bearing sleeve snap ring 343 is used for axially limiting the lower bearing sleeve 342 and the lower bearing 344. Specifically, the upper end of the lower bearing sleeve 342 is inserted into the lower end of the lowermost rubber seat 302, and is connected by the rubber seat positioning pins 324 arranged along the radial direction of the well bore 9. The lower end of the lower bearing sleeve 342 is sleeved on the spline shaft 332 and sealed by a seal ring. The inner wall surface of the lower bearing sleeve 342 is provided with a lower limit ring 345, and the spline sleeve 327 is provided with a supporting step surface for supporting the lower bearing 344. The support step surface cooperates with a lower stop collar 345 to form a lower bearing groove in which the lower bearing 344 is mounted. The lower bearing sleeve clamping ring 343 is clamped with the spline sleeve 327, the lower bearing sleeve clamping ring 343 and the lower limiting ring 345 are matched to form another lower bearing groove, and the lower bearing 344' is arranged in the lower bearing groove so as to reduce sliding friction between the lower bearing sleeve 342 and the lower bearing 344. The lower bearing housing 342, the lower bearing 344, and the lower bearing 344' are prevented from moving in the axial direction thereof by the lower bearing housing snap ring 343. The gap is formed between the lower bearing sleeve clamping ring 343 and the lowermost rubber cylinder seat 302, so that friction can be avoided when the lower bearing sleeve clamping ring 343 rotates relative to the lowermost rubber cylinder seat 302.

As shown in fig. 12, in the embodiment of the present invention, the outer wall surface 312 of the spline shaft 332 is provided with a lower limit step surface 333, the inner wall surface 313 of the spline housing 327 is provided with an upper limit step surface 328, the lower limit step surface 333 is provided with an adjusting pad 334, and the distance between the upper limit step surface 328 and the adjusting pad 334 in the axial direction of the well bore 9 forms a stroke between the spline shaft 332 and the spline housing 327 which can move relatively in the axial direction of the well bore 9. By changing the adjusting pad 334 with a different thickness, the stroke between the spline shaft 332 and the spline housing 327, which is movable relative to each other in the axial direction of the well bore 9, can be changed, and thus, the expansion range of the packing 301 can be adjusted.

As shown in fig. 12, in the embodiment of the present invention, at least one snap ring 335 is provided at the upper end of the spline shaft 332, at least one supporting surface is provided on the inner wall surface 313 of the upper transmission structure 326, and in the drilling state, the spline shaft 332 is suspended and supported on the at least one supporting surface by the at least one snap ring 335. The bearing surface is used to bear the weight of the spline shaft 332 and the attached lower drill 117. Specifically, the inner wall surface 313 of the upper transmission structure 326 is further provided with at least one limiting surface, and the limiting surface is located above the supporting surface, and the range of movement of the upper transmission structure 326 in the axial direction of the shaft 9 relative to the lower transmission structure 331 can be limited by matching the limiting surface with the supporting surface. In this embodiment, a snap ring 335 and a snap ring 335' are provided at the upper end of the spline shaft 332, and the number of support surfaces is one. The snap rings 335 and 335' are arranged at intervals along the axial direction of the spline shaft 332. The spline shaft 332 is suspended from the support surface by the lower snap ring 335, and when the snap ring 335 fails, the spline shaft 332 is moved downward and is suspended from the support surface by the upper snap ring 335', thereby preventing the spline shaft 332 and its associated lower drilling tool 117 from falling into the wellbore 9.

As shown in fig. 6 and 12, the upper transmission structure 326 further includes a double female joint 329 and an upper joint 330, the upper end of the upper joint 330 is connected to the upper drilling tool 117', the lower end of the upper joint 330 is connected to the upper end of the spline housing 327 through the double female joint 329, and the end face of the upper end of the spline housing 327 forms a supporting surface. The end face of the lower end of the upper connector 330 can form a limiting surface, so that the double female connectors 329 and the upper connector 330 are arranged, and the support surface and the limiting surface do not need to be additionally processed, so that the processing is simple. Alternatively, the spline housing, the double female joint and the upper joint may be of an integrally formed structure.

As shown in fig. 6 and 7, the number of the rubber packers 301 may be one, or may be two, three, or more. In this embodiment, a plurality of rubber packers 301 are arranged in the axial direction of the wellbore 9 and are connected by a connection sleeve 325. Thus, the uppermost rubber seat 302' connected by the upper transmission structure 326 and the lowermost rubber seat 302 connected by the lower transmission structure 331 may be two rubber seats of the same rubber packer 301 or two rubber seats of different rubber packers 301. In the drilling state, the two rubber cylinder seats of all rubber cylinder packers 301 are relatively close; in the pulled-up state, both of the two packing units of the packing unit 301 are relatively far apart. Specifically, two ends of the connecting sleeve 325 are inserted into the rubber cylinder seats of two adjacent rubber cylinder packers 301 and are connected by the rubber cylinder seat positioning pins 324.

As shown in fig. 1 and 3, at least one centralizer 4 is further installed on the double-pipe drilling tool 1, the centralizer 4 is arranged close to the wellhead 902 relative to the packer while drilling device 3, and in a drilling state, the centralizer 4 can expand outwards to centralize the double-pipe drilling tool 1; in the pulled-up state, the centralizer 4 can also be retracted inwardly to less than the radial dimension of the well bore 9. As shown in fig. 2 and 4, the rock breaking tool 118 includes a drill bit 115, and in a drilling state, the drill bit 115 can be expanded outwards to drill; the anti-seize drill bit 115 can also retract inwardly to less than the radial dimension of the wellbore 9 in the pulled-up condition. The risk of sticking is further reduced by the cooperation of the packer while drilling device 3, the centralizer 4 and the anti-sticking drill bit 115.

As shown in fig. 1 and 3, in the embodiment of the invention, a double-pipe drilling tool 1 is provided with an anti-blocking counter-punch 5 and a floating counter-punch bit 6, and the anti-blocking counter-punch 5 and the floating counter-punch bit 6 are sequentially arranged above a while-drilling packing device 3 from bottom to top; in the state that the double-pipe drilling tool 1 lifts the drill and meets resistance, the impact piston in the anti-blocking counter-strike device 5 can impact the floating counter-strike drill bit 6 upwards so that the floating counter-strike drill bit 6 impacts the drill upwards. The joint between the while-drilling packing device 3 and the upper drilling tool 117 is most prone to drill sticking, and by installing the anti-sticking impact device 5 and the floating impact drill bit 6 above the while-drilling packing device 3, even if drill sticking occurs, the blocking object above can be removed by reverse drilling of the floating impact drill bit 6, and drill sticking is relieved.

As shown in fig. 1, 3 and 14, the end of the double-pipe drilling tool 1 above the ground is provided with a fluid injection and drainage mechanism 7, the fluid injection and drainage mechanism 7 comprises an injection structure 701, a rotary injection and drainage adapter 702 and a drainage pipe 703, the injection structure 701 is communicated with the fluid injection channel 113 through a flow distribution channel 706 of the rotary injection and drainage adapter 702, and the drainage pipe 703 is communicated with the fluid return channel 114 through a return channel 707 of the rotary injection and drainage adapter 702. Specifically, the injection structure 701 includes a top drive or faucet, with a gooseneck 705 in communication with the fluid injection device via an injection conduit.

As shown in fig. 14, at least one drainage-aiding structure 8 is mounted on the drainage channel 703, and the drainage-aiding structure 8 can inject drainage-aiding fluid into the drainage channel 703 and form a drainage-aiding jet, and the drainage-aiding jet can push the fluid in the drainage channel 703 to drain. Specifically, the drainage assisting structure 8 includes a drainage assisting pipe 802 and a plurality of drainage assisting jet holes 801, the drainage assisting pipe 802 is mounted on the drainage pipe 703, the drainage assisting jet holes 801 are uniformly arranged along the circumferential direction of the drainage pipe 703, and the flow direction of the fluid in the drainage assisting jet holes 801 is inclined toward the flow direction of the fluid in the drainage pipe 703. The drainage assist conduit 802 communicates with the drainage conduit 703 through a plurality of drainage assist jet holes 801. The drainage structures 8 are similar to the above-described flow dividing structures 2, except that the drainage structures 8 are arranged to inject drainage-assisting fluid into the drainage pipeline 703 through a pipeline arranged in addition to form drainage-assisting jet flow. The number of the drainage structures 8 may be one or more, and they may be disposed at different positions at intervals according to the conveying distance of the drainage pipe 703.

As shown in fig. 1 and 3, the rotary injection and discharge adapter 702 is mounted at an end of the double pipe drilling tool 1 above the ground through a reverse circulation damper 704 and communicates with the fluid injection passage 113 and the fluid return passage 114.

As shown in fig. 15 and 16, the present invention can be used not only for reverse circulation drilling but also for forward circulation drilling, i.e., injection of fluid from the passage of the inner tube 101 and closing of the annulus between the outer tube 109 and the inner tube 101. In the embodiment of the present invention, the inner pipe 101 has a conductive structure 121 thereon, and the double pipe drilling tool 1 performs power transmission and signal transmission through the conductive structure 121. By arranging the transmission structure 121 on the inner pipe 101, the double-pipe drilling tool 1 can not only transmit signals but also transmit electric energy, so that the invention can be applied to not only vertical well construction but also horizontal well construction. When the invention is used for a horizontal well, the rock debris bed can be effectively removed, the pressure consumption of a circulating flow field can be accurately controlled, the horizontal section length can be further extended when unconventional oil and gas resources are drilled, and the safe and efficient drilling can be performed in a narrow density window.

As shown in fig. 15 and 16, the inner tube 101 includes a plurality of inner tube segments 102, the conductive structure 121 includes a conductive layer 103, the conductive layer 103 is coated on an outer wall surface 312 of the inner tube segment 102, two adjacent inner tube segments 102 are connected in a matched manner through an inner tube male connector 105 and an inner tube female connector 104, the inner tube male connector 105 is embedded with at least one wire 107', the inner tube female connector 104 is embedded with at least one wire 107, the contact surfaces of the inner tube male connector 105 and the inner tube female connector 104 are provided with at least one conductive contact structure 106' and a conductive contact structure 106 which are matched, and the conductive contact structure 106 'and the conductive contact structure 106 are connected with the corresponding conductive layer 103 through the wires 107' and the wires 107. The outer tube 109 comprises a plurality of outer tube sections 110, and two adjacent outer tube sections 110 are matched and spliced through an outer tube male connector 112 and an outer tube female connector 111. Alternatively, the conductive structure may also include a coil wound around the inner tube.

Specifically, the conductive contact structure 106' and the conductive contact structure 106 may be a plurality of conductive contact points, and the plurality of conductive contact points are arranged at intervals along the circumferential direction of the inner tube 101; or may be a conductive contact surface that is generally toroidal. The number of the conductive contact structures 106 'and 106 is plural, the contact surfaces of the inner pipe male connector 105 and the inner pipe female connector 104 are provided with a plurality of sealing rings 108, and two ends of each group of conductive contact structures are provided with a sealing ring 108, so that the conductive contact structures 106' and 106 are isolated from external fluid, and meanwhile, mutual interference among a plurality of groups of conductive contact structures can be avoided.

The foregoing is merely a few embodiments of the present invention and those skilled in the art may make various modifications or alterations to the embodiments of the present invention in light of the disclosure herein without departing from the spirit and scope of the invention.

Claims (12)

1. A reverse circulation drilling apparatus, comprising:

the double-pipe drilling tool is provided with an outer pipe, an inner pipe and a rock breaking tool, wherein the inner pipe is arranged in the outer pipe in a penetrating manner, an annular space between the outer pipe and the inner pipe forms a fluid injection channel, a channel of the inner pipe forms a fluid return channel, the rock breaking tool is internally provided with an injection channel and a suction channel, the injection channel is communicated with the fluid injection channel, and the suction channel is communicated with the fluid return channel;

The plurality of shunt structures are arranged at intervals along the axial direction of the double-pipe drilling tool;

wherein, a part of fluid in the fluid injection channel flows into the bottom of the well from the injection channel to form rock breaking fluid, and the rock breaking fluid carries rock debris into the fluid return channel under the suction action of the suction channel; another portion of the fluid in the fluid injection channel can flow from the flow dividing structure into the fluid return channel to form a jet, and the jet can push the fluid in the fluid return channel to return upwards.

2. The reverse circulation drilling apparatus of claim 1,

the flow dividing structure is provided with a plurality of flow dividing holes, the plurality of flow dividing holes are distributed at intervals along the circumferential direction of the double-pipe drilling tool, the flow dividing holes are communicated with the fluid injection channel and the fluid return channel, and the flow direction of fluid in the flow dividing holes is inclined upwards.

3. The reverse circulation drilling apparatus of claim 2,

the double-pipe drilling tool comprises at least one upper drilling tool and at least one lower drilling tool, the flow distribution structure comprises a flow distribution nipple, the flow distribution nipple comprises an outer nipple and an inner nipple, an outer pipe of the upper drilling tool is communicated with an outer pipe of the lower drilling tool through the outer nipple, an inner pipe of the upper drilling tool is communicated with an inner pipe of the lower drilling tool through the inner nipple, and the flow distribution hole is formed in the inner nipple.

4. The reverse circulation drilling apparatus of claim 1,

the double-pipe drilling tool is provided with a packer while drilling; in a drilling state, the packer while drilling device can expand outwards to seal a shaft annulus between the double-pipe drilling tool and the shaft; in the drilling state, the while-drilling packer device can retract inwards to be smaller than the radial dimension of the shaft.

5. The reverse circulation drilling apparatus of claim 4,

at least one centralizer is also arranged on the double-pipe drilling tool, the centralizer is arranged close to a wellhead relative to the packer while drilling, and in a drilling state, the centralizer can expand outwards to centralize the double-pipe drilling tool; in the lifted state, the centralizer is also retractable inward to less than the radial dimension of the wellbore.

6. The reverse circulation drilling apparatus of claim 4,

the rock breaking tool comprises an anti-seize drill bit, and in a drilling state, the anti-seize drill bit can expand outwards to drill; in the drill lifting state, the anti-seize drill bit can also retract inwards to be smaller than the radial dimension of the shaft.

7. The reverse circulation drilling apparatus of claim 4,

The anti-blocking counter-impact device and the floating counter-impact drill bit are arranged on the double-pipe drilling tool and are sequentially arranged above the while-drilling packing device from bottom to top;

in the state that the double-pipe drilling tool lifts the drill and meets resistance, the impact piston in the anti-blocking impact device can impact the floating impact drill bit upwards so that the floating impact drill bit impacts the drill upwards.

8. The reverse circulation drilling apparatus of claim 1,

the double-pipe drilling tool is characterized in that a fluid injection and discharge mechanism is arranged at one end, above the ground, of the double-pipe drilling tool, the fluid injection and discharge mechanism comprises an injection structure, a rotary injection and discharge adapter and a discharge pipeline, the injection structure is communicated with the fluid injection channel through a flow distribution channel of the rotary injection and discharge adapter, and the discharge pipeline is communicated with the fluid return channel through a return channel of the rotary injection and discharge adapter.

9. The reverse circulation drilling apparatus of claim 8,

the exhaust pipeline is provided with a plurality of auxiliary exhaust structures which are arranged at intervals along the axial direction of the exhaust pipeline, the auxiliary exhaust structures can inject auxiliary exhaust fluid into the exhaust pipeline and form auxiliary exhaust jet flow, and the auxiliary exhaust jet flow can push the fluid in the exhaust pipeline to be exhausted.

10. The reverse circulation drilling apparatus of claim 8,

the rotary injection and discharge adapter is arranged at one end of the double-pipe drilling tool above the ground through a reverse circulation damper and is communicated with the fluid injection channel and the fluid return channel.

11. The reverse circulation drilling apparatus of claim 1,

the inner pipe is provided with a conducting structure, and the double-pipe drilling tool performs power transmission and signal transmission through the conducting structure.

12. The reverse circulation drilling apparatus of claim 11,

the inner pipe comprises a plurality of inner pipe joints, the conductive structures comprise conductive layers, the conductive layers are coated on the outer wall surfaces of the inner pipe joints, two adjacent inner pipe joints are connected in a matched mode through an inner pipe male connector and an inner pipe female connector, at least one conducting wire is embedded in the inner pipe male connector and the inner pipe female connector, at least one group of matched conductive contact structures are arranged on the contact surfaces of the inner pipe male connector and the inner pipe female connector, and the conductive contact structures are connected with the corresponding conductive layers through corresponding conducting wires.