CN214273581U - Lifting drilling type large-diameter well bottom in-situ pressure maintaining coring drilling tool - Google Patents

Abstract

The utility model discloses a carry brill formula major diameter shaft bottom normal position pressurize coring drilling tool, including positioning mechanism, lifting mechanism, pressurize mechanism and drill bit, positioning mechanism fixes a position the back, triggers the ball valve upset in the lifting mechanism drives the pressurize mechanism through pitching, realizes that the core barrel is airtight to together be rotary motion along with the drilling rod through promoting the drill bit and acquire the core of the rock. The utility model discloses carry to the major diameter and bore the loss that leads to gas in the core, to the gas storage volume difficult problem in the unable accurate evaluation target stratum, the diameter of coring can reach 85 ~ 150 mm. Meanwhile, the accuracy of matching the core property with the formation depth can be ensured by in-situ pressure maintaining and coring at the bottom of the well. The ball valve is adopted for sealing to ensure good sealing performance and pressure maintaining effect, so that in-situ fidelity exploitation of the bottom of the core is further realized, and the requirements on the pressure maintaining sealing performance of the drilling tool during exploration of certain gas deposits are particularly met. The utility model discloses can be applied to fields such as coal bed gas, shale gas, natural gas hydrate and conventional oil gas exploration coring.

Description

Lifting drilling type large-diameter well bottom in-situ pressure maintaining coring drilling tool

Technical Field

The utility model relates to a pressurize coring drilling tool technical field especially relates to a carry brill formula major diameter shaft bottom normal position pressurize coring drilling tool.

Background

In the resource exploration process, the parameter accuracy of reserve evaluation is solved, a calculation basis is provided for production, and the method is important for quickly and effectively obtaining stratum rock cores. At present, shale gas exploration and coal bed gas exploration sampling are performed by adopting a common rope salvage coring drilling tool to obtain samples, and the gas storage capacity of a target layer is evaluated according to the analysis result of the obtained samples. In the sampling process and the core transfer process, along with the reduction of the external pressure, the dissipation of gas in the core is accelerated, so that the gas storage amount of a target stratum cannot be accurately evaluated. In order to obtain more accurate formation information, it is generally required to obtain cores of the formation in situ and with precision.

At present, the existing mechanical pressure-maintaining coring and freezing pressure-maintaining coring can basically meet the conventional sampling requirements, but the pressure-maintaining coring drilling tool is generally of a three-layer tube structure due to the complex internal structure, so that all links in design, processing and use are strictly limited by space, and the diameter of the obtained core is generally smaller. Particularly, the diameter of a core obtained by a rope coring and pressure maintaining drilling tool used in the geological investigation fields of shale gas, natural gas hydrate, coal bed gas and the like is generally less than 48 mm. In addition, the inner drift diameter of the existing drill rod for petroleum, coal bed gas, shale gas, natural gas and the like does not meet the requirement of a large-diameter pressure-maintaining sampling drilling tool to pass through, so that the pressure-maintaining coring drilling tool adopting a rope coring mode is not suitable for the large-diameter drilling field.

With the rapid development of society, the supply of conventional fossil energy is more and more tense, and the demand for exploration and development of unconventional shale gas, coal bed gas and natural gas hydrate is increased day by day, so that the development of an in-situ pressure-maintaining coring drilling tool capable of accurately obtaining large-diameter bottom hole reserve parameters is urgent.

SUMMERY OF THE UTILITY MODEL

The utility model discloses to the not enough of above-mentioned prior art, provide a carry brill formula major diameter shaft bottom normal position pressurize coring drilling tool.

In order to achieve the above object, the present invention provides the following technical solutions:

the utility model provides a carry brill formula major diameter shaft bottom normal position pressurize coring drilling tool, includes positioning mechanism, lifting mechanism, pressurize mechanism and drill bit, positioning mechanism fixes a position the back, triggers the lifting mechanism through the bowling and drives the ball valve upset in the pressurize mechanism, realizes the airtight of core barrel to do rotary motion along with the drilling rod through promoting the drill bit and obtain the core.

Further, the positioning mechanism comprises an outer pipe, a seat pipe, a spring mandrel, a connecting shaft, a connecting pipe, an upper reamer and a lower reamer; the outer pipe is upwards connected with an upper drill rod, downwards connected with a connecting pipe through threads, a spring seat is arranged at the connecting position, a pulling spring is seated on the spring seat, the pulling spring is in a compressed state under the normal downward placement and coring state, and the base pipe and the spring mandrel are limited to move upwards through a limiting pin so as to limit the extension of the pulling spring; the seat tube is connected with the spring mandrel through welding, the spring mandrel is downwards connected with the connecting shaft through threads, and the upper reamer is upwards connected with the connecting pipe through threads.

Furthermore, an overflow hole is formed in the seat pipe.

Furthermore, a mud water outlet hole is formed in the spring mandrel.

Furthermore, the lifting mechanism comprises an upper thrust ball bearing, a copper sleeve, a lower thrust ball bearing, a suspension sleeve and a single-action copper sleeve, wherein the thrust ball bearing, the copper sleeve, the lower thrust ball bearing and the suspension sleeve are sequentially sleeved on the connecting shaft from top to bottom, and the limiting and the fixing are realized through a first gasket and a first locking nut.

Further, the pressurize mechanism includes pressure-measuring pipe, pressure-maintaining pipe and ball valve, the bearing housing is equipped with to the bearing section outside of connecting axle, the bearing housing is downwards through threaded connection pressure-measuring pipe, the pressure-measuring pipe passes reducer union, reducer union is downwards through threaded connection well pipe, outwards through hanging the cover, single action copper sheathing and first hang the ring and sit on the reamer, go up the reamer and pass through threaded connection pressure-maintaining pipe downwards, the pressure-measuring pipe is downwards through threaded connection upper seal joint, the pressure-measuring joint is equipped with in the junction, upper seal joint is downwards through lower extreme female connection rock core coupling, adjusting nut is equipped with in the junction, the rock core coupling passes through external screw thread connection rock core pipe, there is first buffer spring fixed by second gasket and second lock nut in the joint.

Furthermore, an adjusting nut is arranged at the joint of the core pipe joint and the upper sealing joint and used for adjusting the axial position of the core pipe relative to the pressure maintaining pipe.

Further, the core tube part comprises an upper core tube and a lower core tube, the upper core tube and the lower core tube are connected through threads, and the wall thickness of the upper core tube is larger than that of the lower core tube.

Further, the bottom end of the lower core tube is connected with a clamp spring seat through threads, a clamp spring is arranged in the lower core tube, the lower core tube sequentially penetrates through a spring seat ring, a thrust spring seat, an upper ball valve seat, a ball valve, a lower ball valve seat, a second buffer spring, a buffer spring seat and a centering joint from top to bottom, the thrust spring is in a compressed state, the spring seat ring is upwards pushed to be seated on a step in the middle tube and downwards sleeved on the thrust spring seat, the thrust spring seat is abutted against the upper ball valve seat, the ball valve is arranged between the upper ball valve seat and the lower ball valve seat, a through hole is formed in the ball valve, two radial ends of the ball valve are flattened and provided with a ball valve limiting pin, the ball valve and the ball valve seat are arranged in a ball limiting tube, the ball limiting tube is upwards connected with the middle tube through threads, a sealing ring is arranged at the joint, the ball limiting tube is downwards connected with the centering joint through threads, the upper end of the centering joint is provided with the buffer spring seat sleeved with the second buffer spring, and the lower reamer is connected with the lower ball valve seat, the centralizing joint is outwards seated on a second suspension ring, the second suspension ring is arranged at the upper part of the joint of the lower reamer and the drill bit, and the lower reamer and the drill bit are connected in a threaded manner.

Further, the diameter of the drill bit for obtaining the core of the rock is-mm.

Compared with the prior art, the beneficial effects of the utility model are that:

the utility model provides a carry brill formula major diameter shaft bottom normal position pressurize coring drilling tool carries to the major diameter and bores the gaseous loss in the core of the core that coring leads to the gas storage volume difficult problem in the unable accurate evaluation target stratum adopts positioning mechanism location, throws the ball and triggers the ball valve upset among the lifting mechanism, the drive pressurize mechanism, realizes the airtight of core pipe, and isolated environmental change draws stratum core through promoting the drilling rod, and the coring diameter can reach 85 ~ 150 mm. The adoption of the drill extraction and coring reduces the requirements of pressure maintaining and coring on the drilling tool, and the existing drilling tool assembly does not need to be additionally changed. Meanwhile, the accuracy of matching the core property with the formation depth can be ensured by in-situ pressure maintaining and coring at the bottom of the well. The ball valve is adopted for sealing, and the sealing ring is arranged at the key part, so that good sealing performance and pressure maintaining effect are ensured, in-situ fidelity exploitation of the bottom of the well of the rock core is further realized, and the requirements on the pressure maintaining sealing performance of the drilling tool during exploration of certain gas deposits are particularly met. The utility model discloses can be applied to fields such as coal bed gas, shale gas, natural gas hydrate and conventional oil gas exploration coring.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments described in the present invention, and other drawings can be obtained by those skilled in the art according to these drawings.

Fig. 1 is a schematic structural view of a drill-lifting type large-diameter bottom hole in-situ pressure-maintaining core drilling tool provided by the embodiment of the present invention.

Fig. 2 is a schematic structural view of the drill-lifting type large-diameter bottom hole in-situ pressure maintaining coring drilling tool provided by the embodiment of the present invention in a normal lower pipe coring state.

Fig. 3 is a schematic structural view of the drill-lifting type large-diameter bottom hole in-situ pressure maintaining coring drilling tool in a ball-throwing recovery coring state according to the embodiment of the present invention.

Description of reference numerals:

1-a limit pin; 2-an outer tube; 3-an overflow hole; 4-a seat tube; 5-pulling the spring; 6-a spring mandrel; 7-slurry water outlet; 8-spring seats; 9-a connecting shaft; 10-upper thrust ball bearing; 11-a bearing sleeve; 12-a connecting tube; 13-copper sheathing; 14-lower thrust ball bearing; 15-a first gasket; 16-a first locking nut; 17-up-reamer; 18-piezometric tube; 19-hanging the sleeve; 20-single action copper sleeve; 21-a first suspension ring; 22-a reducer union; 23-a pressure measuring connector; 24-upper sealing joint; 25-middle tube; 26-a pressure-maintaining tube; 27-adjusting the nut; 28-core tube joint; 29-a first buffer spring; 30-a second gasket; 31-a second lock nut; 32-upper core barrel; 33-lower core barrel; 34-a spring seat ring; 35-a thrust spring; 36-a thrust spring seat; 37-ball-on-seat; 38-sealing ring; 39-ball valve; 40-ball valve limit pin; 41-a limiting groove; 42-lower ball valve seat; 43-ball limiting tube; 44-a second buffer spring; 45-a buffer spring seat; 46-a second suspension ring; 47-underreamer; 48-centralizing the joint; 49-a snap spring; 50-a clamp spring seat; 51-a drill bit; 52-trigger ball.

Detailed Description

In order to make those skilled in the art better understand the technical solution of the present invention, the present invention will be further described in detail with reference to the accompanying drawings and examples.

As shown in fig. 1, the utility model provides a carry brill formula major diameter shaft bottom normal position pressurize coring drilling tool, including positioning mechanism, lifting mechanism, pressurize mechanism and drill bit, positioning mechanism fixes a position the back, triggers the ball valve upset in the lifting mechanism drives the pressurize mechanism through pitching, realizes the airtight of core pipe to together be rotary motion and acquire the core through promoting the drill bit along with the drilling rod.

Specifically, the positioning mechanism comprises an outer pipe 2, a seat pipe 4, a spring mandrel 6, a connecting shaft 9, a connecting pipe 12, an upper reamer 17, a lower reamer 47 and the like; the lifting mechanism comprises an upper thrust ball bearing 10, a copper sleeve 13, a lower thrust ball bearing 14, a suspension sleeve 19, a single-action copper sleeve 20 and the like, and the pressure maintaining mechanism comprises a pressure measuring pipe 18, a pressure maintaining pipe 26, a ball valve 39 and the like.

Wherein, the outer pipe 2 is connected with an upper drill rod upwards, the outer pipe is connected with a connecting pipe 12 downwards through a thread, a spring seat 8 is arranged at the joint, a pulling spring 5 is seated on the spring seat, the pulling spring 5 is in a compression state under the normal lowering and coring state, the seat pipe 4 and a spring mandrel 6 are limited to go upwards through a limiting pin 1 so as to limit the extension of the pulling spring 5, an overflow hole 3 is arranged on the seat pipe 4, a mud water outlet hole 7 is arranged on the spring mandrel 6, the seat pipe 4 is connected with the spring mandrel 6 through welding, the spring mandrel 6 is connected with a connecting shaft 9 downwards through a thread, an upper thrust ball bearing 10, a copper bush 13 and a lower thrust ball bearing 14 are sequentially sleeved on the connecting shaft 9 from top to bottom, the limitation and the fixation are realized through a first gasket 15 and a first locking nut 16, a bearing bush 11 is arranged outside a bearing section of the connecting shaft 9, the bearing bush 11 is connected with a piezometer tube 18 downwards through a thread, the piezometer tube 18 passes through a reducer union 22, the reducing joint 22 is downwards connected with a middle pipe 25 through threads, outwards sits on an upper reamer 17 through a suspension sleeve 19, a single-action copper sleeve 20 and a first suspension ring 21, the upper reamer 17 is upwards connected with a connecting pipe 12 through threads, the upper reamer is downwards connected with a pressure maintaining pipe 26, the pressure maintaining pipe 18 is downwards connected with an upper sealing joint 24 through threads, a pressure measuring joint 23 is arranged at the joint, the upper sealing joint 24 is downwards connected with a core pipe joint 28 through lower-end internal threads, an adjusting nut 27 is arranged at the joint, the core pipe joint 28 is connected with a core pipe 32 through external threads, a first buffer spring 29 fixed by a second gasket 30 and a second locking nut 31 is arranged in the joint, the upper core pipe 32 is in threaded connection with the lower core pipe 33, the bottom end of the lower core pipe 33 is connected with a clamp spring seat 50 through threads, a clamp spring 49 is arranged in the lower core pipe 33, and the lower core pipe 33 sequentially penetrates through the spring seat ring 34, a thrust spring 35 and a thrust spring from top to bottom, A thrust spring seat 36, an upper ball valve seat 37, a ball valve 39, a lower ball valve seat 42, a second buffer spring 44, a buffer spring seat 45 and a centering joint 48, wherein the thrust spring 35 is in a compressed state, an upward thrust spring seat ring 34 is seated on a step in the middle pipe 25 and is downwards sleeved on the thrust spring seat 36, the thrust spring seat 36 is pressed against the upper ball valve seat 37, the ball valve 39 is arranged between the upper ball valve seat 37 and the lower ball valve seat 42, a through hole is formed in the ball valve 39, two radial ends of the ball valve are flattened and are provided with a ball valve limiting pin 40, the ball valve and the ball valve seat are arranged in a ball limiting pipe 43, the ball limiting pipe 43 is upwards connected with the middle pipe 25 through threads, a sealing ring 38 is arranged at the connection part, a limiting groove 41 is formed in the ball limiting pipe 43 and is downwards connected with the centering joint 48 through threads, the upper end of the centering joint 48 is provided with the buffer spring seat 45 sleeved on the second buffer spring 44 and is further connected with the lower ball valve seat 42, the centering joint 48 is outwards seated on a second suspension ring 46, the second suspension ring 46 is mounted on the upper portion of the junction between the under-reamer 47 and the drill bit 51, and the under-reamer 47 and the drill bit 51 are connected by means of a screw thread.

The drill bit comprises a connecting shaft 9, all parts on the upper part of the connecting shaft, an outer pipe 2 on the outer layer, a connecting pipe 12, an upper reamer 17, a pressure maintaining pipe 26, a lower reamer 47 and a drill bit 51 which all rotate along with a drill rod during normal drilling, and the lower part of the connecting shaft 9 cannot rotate along with the drill due to the existence of a single-action structure formed by the thrust ball bearing 10, the copper sleeve 13, the lower thrust ball bearing 14, the suspension sleeve 19 and the single-action copper sleeve 20.

Wherein the adjusting nut 27 is arranged at the joint of the core tube joint 28 and the upper sealing joint 24, and the axial position of the core tube part relative to the pressure-maintaining tube can be adjusted; the core tube part comprises an upper core tube 32 and a lower core tube 33, and the difference between the two parts is that the wall of the upper core tube 32 is thicker, so that the core tube can bear larger axial force when the core is extracted and drilled, the core tube is prevented from being broken by pulling, and the setting purpose of the first buffer spring 29 is the same.

In the actual drilling and coring process, the drilling tool is in two states in sequence: normal drilling coring state and shot recovery coring state. Wherein the transition from the normal drill-down coring condition to the ball recovery coring condition is triggered by the throwing of a trigger ball 52 into the drill pipe internal passage.

In a normal drilling and coring state, as shown in fig. 2, in a designed core section of a drilling hole, the drilling tool drills in a normal core lowering and coring state, a core gradually enters a core tube, at the moment, the limiting pin 1 is in a set position, the pulling spring 5 is in a compression state, drilling fluid flows to the bottom of the hole through a channel in the drilling tool, the part below the connecting shaft 9 cannot rotate while drilling due to the single-acting structure formed by the thrust ball bearing 10, the copper sleeve 13, the lower thrust ball bearing 14, the suspension sleeve 19 and the single-acting copper sleeve 20, and the core gradually enters the core tube along with the footage of the drilling tool. Under the normal drilling and coring state, the drilling fluid passes through the inner channels of the seat pipe 4 and the spring mandrel 6 and enters the annular space of the outer casing pipe and the middle pipe through the mud water outlet hole 7 to flow to the bottom of the hole.

In the core shooting recovery coring state, as shown in fig. 3, when the core barrel is filled with the core, the core is firstly clamped by lifting the drill, then the trigger ball 52 is thrown to the inner channel of the drill rod, so that the drilling tool is switched to the core shooting recovery coring state, the trigger ball descends along the inner channel of the drill rod until reaching the upper end of the seat tube 4, the circulation channel of the drilling fluid is blocked, the trigger ball is pushed downwards under the action of inertia and mud pump pressure, the seat tube 4 is further pushed, the limit pin 1 is sheared under the action of thrust, the seat tube 4 and the spring mandrel 6 continue descending in a short time, so that the pulling spring 5 is further compressed, when the pulling spring 5 is compressed to a certain limit, the pulling force is rapidly increased in a short time, when the pulling force is large enough, the spring mandrel 6, the seat tube 4 and the trigger ball are pushed upwards, the seat tube 4 is pushed out of the outer tube, the whole internal structure of the drilling tool is further driven to sequentially run upwards from top to bottom, until the spring mandrel 6 reaches the highest position, the upper sealing joint 24 is tightly matched with the reducing joint 22 at the moment, the upper end in the middle pipe is sealed under the action of the sealing ring, meanwhile, the lower core barrel 33 and the clamp spring seat 50 are lifted away from an inner channel of the ball valve 39, the ball valve 39 moves downwards under the action of the thrust spring 35, the ball valve 39 turns over 90 degrees in the descending process due to the limitation of the ball valve limiting pin 40 and the limiting groove 41, the inner channel of the upper ball valve seat 37 is sealed, a sealed space is formed together with the ball limiting pipe 43, meanwhile, the lower end in the middle pipe is sealed by the sealing ring 38 arranged at the joint of the ball limiting pipe 43, the middle pipe 25, the ball limiting pipe 43 and the upper ball valve seat 37, and the in-situ bottom hole pressure maintaining of the core is realized.

Under the state of ball throwing, recovering and coring, the drilling fluid enters the inner channels of the seat tube 4 and the spring mandrel 6 through the overflow holes on the seat tube (4), enters the annular space of the outer casing and the middle tube through the slurry water outlet hole 7 and then flows to the bottom of the hole. And the drilling tool is maintained in a ball-throwing recovery coring state after ball throwing is triggered, and the core tube and the drill rod are lifted out for drilling under a good sealing pressure-maintaining environment, so that the bottom hole in-situ pressure-maintaining coring of the large-diameter core is realized.

Example 1

The utility model discloses a realize the major diameter and core to phi 216 mm's coring bit is for example, and drill bit internal diameter 124 mm, design outer tube diameter are phi 194mm, and the coring diameter is between 85mm ~ 90mm (90mm needs the structure compacter), and the drilling tool total length 3m, core tube length can reach 1.1m, and the single is carried the brill and can be extracted 0.50m ~ 1.00 m's rock core. The limiting pin (1) is a brass pin with the diameter of 15mm (two), the maximum bearing shearing force is about 1 ton, and the shearing strength of the brass is calculated according to 30 MPa. The drilling tool supported by the pulling spring (5) has the self weight, the upward height of the pulling spring (5) reaches 380mm, namely the compressed length is 500mm, the extended length is 880mm, correspondingly, the upward height of the core barrel is 380mm, meanwhile, the length of the seat pipe (4) needs to reach 450mm, and under the normal drilling and coring state, the distance from the highest point of the upper end of the ball valve (39) to the lower end of the clamp spring seat (50) needs to reach 372.6 mm. The wire diameter of the pulling spring (5) is 12mm, the thread pitch is 100mm, the total length is 1000mm, the compression force is 92.16Kg when the spring is compressed to 880mm, and the compression force is 384Kg when the spring is compressed to 500 mm. The outer diameter of the ball valve (39) is preliminarily selected to be 155mm, the central hole is 96mm, and the coring diameter can reach 85 mm-90 mm.

Example 2

The utility model discloses a realize the major diameter and core to phi 311 mm's coring bit is for example, drill bit internal diameter 214 mm, and the outer tube diameter of design coring is phi 298mm, and the coring diameter can reach 145mm ~ 150mm (150mm needs the structure compacter), and normal position pressurize coring drilling tool overall length is 3.2m, and rock core pipe length can reach 1.1m, and the single is carried to bore and can be extracted the rock core of 0.50m ~ 1.00 m. The limiting pin 1 is a brass pin, the shearing strength of the limiting pin is calculated according to 30MPa, the diameter of the limiting pin is 15mm (two or three), and the maximum shearing force is about 1 ton. The dead weight of the drilling tool supported by the pulling spring 5, the height of the upward spring of the pulling spring 5 reaches 380mm, namely the length after compression is 500mm, the length after extension is 880mm, correspondingly, the upward height of the core barrel is 380mm, meanwhile, the length of the seat tube 4 needs to reach 450mm, and under the normal drilling and coring state, the distance from the highest point of the upper end of the ball valve 39 to the lower end of the jump ring seat 50 needs to reach 372.6 mm. The pull-up spring 5 is designed and installed so that the wire diameter is 12mm, the thread pitch is 100mm, the total length is 1000mm, the compression force is 92.16Kg when the spring is compressed to 880mm, and the compression force is 384Kg when the spring is compressed to 500 mm. The outer diameter of the ball valve 39 is initially selected to be 230mm, the center hole is 160 mm, and the coring diameter is 140-150 mm.

Obviously, the above description is only a preferred embodiment of the present invention, and is a part of the embodiments of the present invention, not all embodiments. The utility model discloses a protection scope is not limited to above-mentioned embodiment, all belong to the utility model discloses a technical scheme of principle all belongs to the utility model discloses a protection scope. It will be apparent to those skilled in the art that other various changes and modifications can be made based on the above-described technical solutions and concepts, and all other embodiments obtained without inventive work are within the scope of the present invention.

Claims (10)

1. The drill lifting type large-diameter in-situ pressure maintaining and coring drilling tool at the bottom of a well is characterized by comprising a positioning mechanism, a lifting mechanism, a pressure maintaining mechanism and a drill bit, wherein after the positioning mechanism is positioned, the lifting mechanism is triggered by throwing a ball to drive a ball valve in the pressure maintaining mechanism to overturn so as to realize the sealing of a core tube, and the drill bit is lifted to rotate along with a drill rod to obtain a core.

2. The lift-drilling large-diameter bottom-hole in-situ pressure-maintaining core drill tool according to claim 1, wherein the positioning mechanism comprises an outer tube (2), a seat tube (4), a spring mandrel (6), a connecting shaft (9), a connecting tube (12), an upper reamer (17) and a lower reamer (47); the outer pipe (2) is upwards connected with an upper drill rod, downwards connected with a connecting pipe (12) through threads, a spring seat (8) is arranged at the connecting position, a pulling spring (5) is seated on the spring seat, the pulling spring (5) is in a compressed state in a normal downward-placing and coring state, the seat pipe (4) and a spring mandrel (6) are limited to move upwards through a limiting pin (1), and then the pulling spring (5) is limited to extend; the seat tube (4) is connected with the spring mandrel (6) through welding, the spring mandrel (6) is downwards connected with the connecting shaft (9) through threads, and the upper reamer (17) is upwards connected with the connecting tube (12) through threads.

3. The lift-drill large-diameter bottom-hole in-situ pressure-maintaining core drill according to claim 2, characterized in that the seat pipe (4) is provided with an overflow hole (3).

4. The lift-drill large-diameter bottom-hole in-situ pressure-maintaining core drill tool according to claim 2, wherein the spring mandrel (6) is provided with a slurry water outlet hole (7).

5. The drill-lifting type large-diameter well bottom in-situ pressure-maintaining coring drill tool as claimed in claim 2, characterized in that the lifting mechanism comprises an upper thrust ball bearing (10), a copper sleeve (13), a lower thrust ball bearing (14), a suspension sleeve (19) and a single-action copper sleeve (20), wherein the thrust ball bearing (10), the copper sleeve (13), the lower thrust ball bearing (14) and the suspension sleeve (19) are sequentially sleeved on the connecting shaft (9) from top to bottom, and are limited and fixed through a first gasket (15) and a first lock nut (16).

6. The drill-lifting type large-diameter well bottom in-situ pressure maintaining and coring drilling tool as claimed in claim 5, wherein the pressure maintaining mechanism comprises a pressure measuring pipe (18), a pressure maintaining pipe (26) and a ball valve (39), a bearing sleeve (11) is mounted outside a bearing section of the connecting shaft (9), the bearing sleeve (11) is connected with the pressure measuring pipe (18) downwards through a thread, the pressure measuring pipe (18) penetrates through a reducer union (22), the reducer union (22) is connected with a middle pipe (25) downwards through a thread, the bearing sleeve (11) outwards sits on an upper reamer (17) through a hanging sleeve (19), a single-action copper sleeve (20) and a first hanging ring (21), the upper reamer (17) is connected with the pressure maintaining pipe (26) downwards through a thread, the pressure measuring pipe (18) is connected with an upper sealing joint (24) downwards through a thread, the pressure measuring joint (23) is mounted at the connection, the upper sealing joint (24) is connected with a core pipe joint (28) downwards through a lower end inner thread, the adjusting nut (27) is arranged at the joint, the core tube joint (28) is connected with the core tube through external threads, and a first buffer spring (29) fixed by a gasket (30) and a second locking nut (31) is arranged in the joint.

7. A drill-lifting large-diameter bottom-hole in-situ pressure-maintaining core drill tool according to claim 6, characterized in that the joint of the core tube joint (28) and the upper sealing joint (24) is provided with an adjusting nut (27) for adjusting the axial position of the core tube section relative to the pressure-maintaining tube (26).

8. The pull-drill large-diameter bottom-hole in-situ pressure-maintaining core drill tool according to claim 7, wherein the core tube part comprises an upper core tube (32) and a lower core tube (33), the upper core tube (32) and the lower core tube (33) are connected by screw threads, and the wall thickness of the upper core tube (32) is greater than that of the lower core tube (33).

9. The drill-lifting type large-diameter well bottom in-situ pressure-maintaining and coring drill tool as claimed in claim 8, wherein the bottom end of the lower core barrel (33) is connected with a clamp spring seat (50) through a screw thread, a clamp spring (49) is arranged in the lower core barrel, the lower core barrel (33) sequentially penetrates through a spring seat ring (34), a thrust spring (35), a thrust spring seat (36), an upper ball seat ring (37), a ball valve (39), a lower ball seat (42), a second buffer spring (44), a buffer spring seat (45) and a centralizing joint (48) from top to bottom, the thrust spring (35) is in a compressed state, the spring seat ring (34) is upwards pushed to be seated on a step in the middle pipe (25) and downwards sleeved on the thrust spring seat (36), the thrust spring seat (36) is abutted against the upper ball seat (37), the ball valve (39) is arranged between the upper ball seat (37) and the lower ball seat (42), and a through hole is arranged in the ball valve (39), the radial two ends are flattened and provided with ball valve limiting pins (40), a ball valve and a ball valve seat are arranged in a ball limiting pipe (43), the ball limiting pipe (43) is upwards connected with a middle pipe (25) through threads, a sealing ring (38) is arranged at the joint, a limiting groove (41) is formed in the ball limiting pipe (43), a centering joint (48) is downwards connected through threads, a buffer spring seat (45) sleeved with a second buffer spring (44) is arranged at the upper end of the centering joint (48), the centering joint is further connected with a lower ball valve seat (42), the centering joint (48) outwards sits on a second suspension ring (46), the second suspension ring (46) is arranged at the upper part of the joint of a lower reamer (47) and a drill bit (51), and the lower reamer (47) and the drill bit (51) are connected in a threaded manner.

10. The lift-drilling large-diameter bottom-hole in-situ pressure-maintaining core drilling tool according to claim 1, wherein the diameter of the drill bit to obtain the core is between 85mm and 150 mm.

Images