CN112282651A

CN112282651A - Downhole drilling and sealing tool and water drainage construction method

Info

Publication number: CN112282651A
Application number: CN202011263363.6A
Authority: CN
Inventors: 丁同福; 方有向; 石德洲; 张凯; 万玉柱; 张安东; 潘怀义
Original assignee: Huainan Mining Group Co Ltd
Current assignee: Huainan Mining Group Co Ltd
Priority date: 2020-11-12
Filing date: 2020-11-12
Publication date: 2021-01-29

Abstract

The invention discloses a downhole drilling and hole sealing tool, which relates to the technical field of coal mine gas extraction and comprises a drilling device and a grouting sleeve device; the drilling device comprises a guiding expanding bit and a plurality of centralizers; the centralizers comprise centralizer bodies, first drill rods and second drill rods; one end of the guiding hole expanding drill bit is in threaded connection with one end of the first drill rod; the grouting sleeve device comprises a first sleeve, a second sleeve, a guide shoe, a first flange plate and a first connecting pipe. The invention also discloses a water drainage method adopting the tool. The invention has the beneficial effects that: the construction method is suitable for drilling holes, lowering pipes and fixing pipes for large-diameter drainage water in the well. By adopting the construction method, the guide expanding bit drills in the drilling process, the centralizer straightens the drilling track to ensure that the drilling track meets the pipe descending requirement, and the bulge on the side wall of the centralizer main body can polish the unsmooth part of the hole wall in the drilling process, so that the hole is easy to form.

Description

Downhole drilling and sealing tool and water drainage construction method

Technical Field

The invention relates to the technical field of coal mine gas extraction, in particular to an underground drilling and sealing tool and a drainage construction method.

Background

After the mine is permanently closed, the height of the mine waterline gradually rises, and the safety production of the adjacent mine is seriously threatened. Therefore, a group of large-diameter drainage drill holes are required to be constructed in the roadway at the boundary of the closed mine and the adjacent mine field, a hole sealing sleeve is plugged into the drainage drill holes, an annular area between the hole sealing sleeve and the drill holes is sealed, a drill bit with the diameter smaller than that of the hole sealing sleeve is used for drilling into a water-bearing rock stratum or a target rock stratum from the hole sealing sleeve, and a gate valve is controlled to drain accumulated water caused by residual water inflow of the closed mine.

The patent with publication number CN204511370U discloses a controllable water-discharging drilling hole sealing sleeve device, which is used to plug the sealing sleeve into a water-discharging drill hole, but the patent does not describe how to construct a water-discharging drill hole, and it is difficult to perform water-discharging drilling hole forming by using a conventional drilling tool.

Disclosure of Invention

The invention provides a hole sealing tool for underground drilling, which aims to solve the technical problem that the conventional drilling tool is difficult to drain, drill and form holes.

The invention solves the technical problems through the following technical means:

the invention provides a downhole drilling and sealing tool, which comprises a drilling device and a grouting sleeve device, wherein the drilling device is provided with a drilling hole;

the drilling device comprises a first drill bit, a guiding and expanding drill bit and a centralizer, wherein one end of the guiding and expanding drill bit is provided with internal threads, the number of the guiding and expanding drill bits is at least two, the diameters of the guiding and expanding drill bits are sequentially increased, and the diameter of the first drill bit is equal to the minimum diameter of the guiding and expanding drill bit;

the number of the centralizers is at least two, each centralizer comprises a centralizer body, a first drill rod and a second drill rod, the centralizer body is cylindrical, and a bulge is arranged on the outer side wall of the centralizer body; the centralizer comprises a centralizer body, a first drill rod, a second drill rod and a control device, wherein the first drill rod and the second drill rod are respectively positioned at two ends of the centralizer body; one end of the guiding hole expanding drill bit is in threaded connection with one end of the first drill rod;

the grouting sleeve device comprises a first sleeve, a second sleeve, a guide shoe, a first flange plate and a first connecting pipe, wherein one end of the guide shoe is located at the bottom end of the first sleeve, one end of the second sleeve is sleeved on the first sleeve, the other end of the second sleeve is provided with the first flange plate, and the first connecting pipe is connected with the first flange plate.

The working principle is as follows:

reaming: firstly, a first drill bit is adopted for drilling, then a guiding hole expanding drill bit from a small diameter to a large diameter is adopted for sequentially expanding holes, one centralizer is arranged at one end of the head of the guiding hole expanding drill bit, and then the rest centralizers are sequentially connected in a threaded manner.

Tube laying: and placing the guide shoe, the first sleeve and the second sleeve in the drill hole in sequence, then installing the first flange plate and the first connecting pipe at the end part of the second sleeve, and then grouting into the first connecting pipe.

Has the advantages that: when the drilling and hole sealing tool disclosed by the invention is used for drilling, the guide expanding bit drills, the centralizer straightens the drilling track to ensure that the drilling track meets the pipe laying requirement, and the protrusions on the side wall of the centralizer main body can polish the parts with unsmooth hole walls in the drilling process, so that holes are easy to form.

Preferably, the guiding reaming bit comprises a first guiding bit, a second guiding bit, a connecting rod and a reaming piece, the first guiding bit and the second guiding bit are both cylindrical, one end of the first guiding bit is connected with one end of the second guiding bit, the other end of the second guiding bit is connected with one end of the connecting rod, the other end of the connecting rod is provided with internal threads, and the first guiding bit, the second guiding bit and the connecting rod are sequentially communicated and coaxially arranged;

the reaming piece is circumference setting along second pilot bit lateral wall, the cross-section of reaming piece is right trapezoid, the longer base and the second pilot bit lateral wall of reaming piece are connected, the diameter of first pilot bit equals with the diameter of second pilot bit.

Preferably, the first drill rod and the second drill rod are provided with helical grooves on the side walls.

Preferably, the length of the first drill rod is equal to the length of the second drill rod, and the diameter of the first drill rod is equal to the diameter of the second drill rod.

Preferably, the centralizer body has a diameter smaller than a diameter of the first pilot bit.

Preferably, the number of the centralizers is six, and the six centralizers are sequentially in threaded connection.

Preferably, the guide shoe is tapered.

Preferably, the downhole drilling and hole sealing tool further comprises a mud purification device, wherein the mud purification device comprises a water tank, a sedimentation tank, a mud tank, a first mud suction pipe, a first mud pump and a first mud discharge pipe, the water tank is communicated with the sedimentation tank, the sedimentation tank is communicated with the mud tank, one end of the first mud suction pipe is connected with the mud tank, the other end of the mud suction pipe is connected with the first mud pump, one end of the mud discharge pipe is connected with the first mud pump, and the other end of the mud discharge pipe is connected with one end of a second drill rod.

The working principle is as follows: the method comprises the steps of arranging a water tank near a drill hole, enabling slurry after drilling to flow into the water tank, then flowing into a sedimentation tank, settling through the sedimentation tank, clearing useless solid phases such as rock debris and the like in the slurry, blending the slurry at any time, keeping and stabilizing the performance of the slurry, discharging the settled slurry into a slurry tank, pumping the slurry into a slurry discharge pipe from a slurry suction pipe through a first slurry pump, and finally entering a second drill rod so as to enter a guide hole expanding drill bit and perform hole sweeping.

Has the advantages that: the mud is circularly purified by the mud purifying device, the performance of the mud is kept and stabilized, and virtuous circle is achieved.

Preferably, the number of the sedimentation tanks is two, and the two sedimentation tanks are communicated in sequence.

The second technical problem to be solved by the invention is that the conventional drilling tool is difficult to drain, drill and form holes, and the invention provides a method for draining water by using the drilling and sealing tool.

A construction method adopting the drainage drilling hole sealing tool comprises the following steps:

(1) front guide and rear centralizing and grading reaming: firstly, drilling by using a first drill bit, after grouting, continuously adopting the first drill bit for throwing holes, then sequentially reaming by using a guide reaming drill bit from a small diameter to a large diameter, firstly installing the first drill rod thread of one centralizer at one end of the guide reaming drill bit with the smallest diameter in the reaming process, sequentially connecting the first drill rods and the second drill rods of the other centralizers by threads for reaming, and then sequentially replacing the guide reaming drill bits according to the diameters;

(2) when the guide expanding bit with the largest diameter is replaced, the first drill rod thread of one centralizer is installed at one end of the guide expanding bit with the smallest diameter, then the hole expanding is carried out, then one centralizer is continuously added for expanding the hole, and the hole expanding is finished after all the centralizers are sequentially added;

(3) guiding the shoe, the first sleeve and the second sleeve downwards into the drill hole, mounting the first flange plate and the first connecting pipe at the end part of the second sleeve, filling a gap between the second sleeve and the hole wall with slurry, and injecting slurry into the first connecting pipe for hole sealing after the gap is solidified;

(4) after solidification, continuously adopting the first drill to the designed hole depth, if water does not return, immediately pulling out the drill, and if the drill hole is normally backwashed, continuously constructing for 3-5 m;

(5) sequentially reaming by adopting a guiding reaming bit from a small diameter to a large diameter, wherein in the reaming process, the first drill rod thread of one centralizer is installed at one end of the guiding reaming bit with the smallest diameter, the first drill rods and the second drill rods of the other centralizers are sequentially connected by threads for reaming, then the guiding reaming bit is sequentially replaced according to the diameter, and the diameter of the reamed hole is smaller than that of the reamed hole in the step (2);

(6) the drilling and hole sealing tool further comprises a third sleeve, a second flange plate and a high-pressure gate valve, wherein the third sleeve is arranged in the hole downwards, then grouting and hole sealing are carried out, after solidification, a first drill bit is adopted to sweep the hole and drill to the designed hole depth, the second flange plate is arranged at the pipe orifice of the third sleeve, and then the first drill bit is continuously adopted to drill to the designed hole depth.

Has the advantages that: the construction method is suitable for drilling holes, lowering pipes and fixing pipes for large-diameter drainage water in the well.

By adopting the construction method, the guide expanding bit drills in the drilling process, the centralizer straightens the drilling track to ensure that the drilling track meets the pipe descending requirement, and the bulge on the side wall of the centralizer main body can polish the unsmooth part of the hole wall in the drilling process, so that the hole is easy to form.

The centralizer is added at every turn in the drilling process, and the hole wall is smoother after reaming at every turn, so that the drilling resistance can be prevented from being overlarge, and the operation safety is improved.

Preferably, the first drill bit is a phi 94mm composite bit, and the first drill bit is used for drilling to 33m in the step (1).

Preferably, the number of the guiding reamer bits is four, the guiding reamer bits are reducing guiding reamer bits, and the diameters of the four reducing guiding reamer bits are as follows: phi 94mm to phi 153mm, phi 153mm to phi 196mm, phi 196mm to phi 248mm, and phi 248mm to phi 268 mm.

Preferably, the diameter of the centralizer body is Φ 240 mm.

Preferably, the number of the centralizers is six, and when the guiding reaming bit with the largest diameter of phi 268mm is used, one centralizer is installed in the first reaming, two centralizers are added in the second reaming, and three centralizers are added in the third reaming.

Preferably, the first casing is an oil casing with phi 219mm, and the length of the first casing is not less than 20 m.

Preferably, in the step (3), an iron pipe with a length of 2m is placed between the second casing and the hole wall, slurry is introduced into the iron pipe, and the gap between the second casing and the hole wall is filled with the slurry.

Preferably, in the step (5), a guiding reamer bit with a diameter of 94mm changing into 153mm and a diameter of 153mm changing into 196mm is used for reaming in sequence.

Preferably, the third sleeve comprises a phi 127mm petroleum flower sleeve and a phi 177.8mm petroleum sleeve, the phi 127mm petroleum flower sleeve and the phi 177.8mm petroleum sleeve are in diameter-variable connection, and a second flange plate is mounted at a pipe orifice of the phi 177.8mm petroleum sleeve.

The invention has the advantages that: the construction method is suitable for drilling holes, lowering pipes and fixing pipes for large-diameter drainage water in the well.

When the drilling and hole sealing tool disclosed by the invention is used for drilling, the guide expanding bit drills, the centralizer straightens the drilling track to ensure that the drilling track meets the pipe laying requirement, and the protrusions on the side wall of the centralizer body can polish the parts with unsmooth hole walls in the drilling process. And the opening difficulty is reduced.

Drawings

Fig. 1 is a schematic structural view of a pilot reamer bit according to embodiment 1 of the present invention;

fig. 2 is a schematic structural view of a centralizer in embodiment 1 of the present invention;

FIG. 3 is a schematic structural view of a grouting bushing apparatus according to embodiment 1 of the present invention;

FIG. 4 is a schematic structural view of a slurry purification apparatus according to embodiment 2 of the present invention;

FIG. 5 is a schematic view showing the circulation of grouting in example 3 of the present invention;

fig. 6 is a schematic structural view of a second sleeve and a third sleeve in embodiment 3 of the present invention;

in the figure: a first pilot bit 11; a second pilot bit 12; a connecting rod 13; a reamer 14; a centralizer body 21; a first drill rod 22; a second drill rod 23; the projections 24; a first sleeve 31; a second sleeve 32; a guide shoe 33; a first flange 34; a first connecting pipe 35; cotton yarn 36; a water tank 41; a settling tank 42; a mud pit 43; a first suction pipe 44; a first mud pump 45; a first discharge pipe 46; an iron pipe 51; a first slurry outlet pipe 52; a first grout pipe 53; a second mud pump 54; a grouting barrel 55; a second suction pipe 56; a second flange 57; a third sleeve 58.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are some embodiments of the present invention, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It will be understood that when an element is referred to as being "secured to" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present.

It is noted that, in this document, relational terms such as first and second, and the like, if any, are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.

Example 1

A downhole drilling and sealing tool, as shown in figures 1-3, comprises a drilling device and a grouting sleeve device.

As shown in fig. 1 and 2, the drilling apparatus includes a pilot reamer head and a plurality of centralizers. The guiding reaming bit comprises a first guiding drill bit 11, a second guiding drill bit 12, a connecting rod 13 and a reaming piece 14, wherein the first guiding drill bit 11 and the second guiding drill bit 12 are both cylindrical, and the diameter of the first guiding drill bit 11 is equal to that of the second guiding drill bit 12.

First pilot bit 11's center, second pilot bit 12's center, coaxial through-hole is seted up at connecting rod 13's center, first pilot bit 11, second pilot bit 12 and connecting rod 13 communicate in proper order, and coaxial setting, welded fixed connection is passed through with second pilot bit 12's one end to first pilot bit 11's one end, for convenient drilling, first pilot bit 11's the other end is equipped with the radian, welded fixed connection is passed through with connecting rod 13's one end to the other end of second pilot bit 12, connecting rod 13's through-hole inside wall is equipped with the internal thread.

The reaming piece 14 is circumference setting along second pilot bit 12 lateral wall, and the number of reaming piece 14 is a plurality of, and specific number sets up according to actual need, and the cross-section of reaming piece 14 is right trapezoid, and the longer base of reaming piece 14 is connected with second pilot bit 12 lateral wall, and its connected mode adopts the welding but not only is limited to the welding. The side walls of the first drill rod 22 and the second drill rod 23 are provided with spiral grooves, and the spiral grooves have a chip removal effect.

The number of direction reamer bit is a plurality of, and the diameter of first direction reamer bit 11 increases in proper order among a plurality of direction reamer bits, and the number of direction reamer bit is four in this embodiment, is first direction reamer bit, second direction reamer bit, third direction reamer bit and fourth direction reamer bit respectively. And (4) carrying out stepped reaming by adopting guide reamer bits with different diameters.

The diameter of a first guide reamer bit 11 in the guide reamer bit is R1, the diameter of the circumference where a reamer 14 on a second guide reamer bit 12 is located is R2, R2 is larger than R1, the diameter of the guide reamer bit is represented as phi R1 to R2, the diameter of the first guide reamer bit is changed from phi 94mm to phi 153mm, the diameter of the second guide reamer bit is changed from phi 153mm to phi 196mm, the diameter of a third guide reamer bit is changed from phi 196mm to phi 248mm, and the diameter of a fourth guide reamer bit is changed from phi 248mm to 268 mm.

The centralizer includes centralizer body 21, first drilling rod 22 and second drilling rod 23, and centralizer body 21 is cylindricly, and the lateral wall of centralizer body 21 distributes protrudingly 24, and the number of protruding 24 sets up according to actual need.

First drilling rod 22 and second drilling rod 23 are fixed mounting respectively at the both ends center of centralizer body 21, first drilling rod 22, second drilling rod 23 and the coaxial setting of centralizer body 21, centralizer body 21 center is equipped with the through-hole with first drilling rod 22 intercommunication along its length direction, centralizer body 21 and first drilling rod 22, second drilling rod 23 intercommunication, the one end that centralizer body 21 was kept away from to first drilling rod 22 is equipped with the external screw thread, the one end that centralizer body 21 was kept away from to second drilling rod 23 is equipped with the internal thread, the direction reamer head has the one end threaded connection that internal thread and first drilling rod 22 have the external screw thread. The diameter of the centralizer body 21 is smaller than the diameter of the first pilot bit 11.

As shown in fig. 3, the grouting bushing device includes a first bushing 31, a second bushing 32, a guide shoe 33, a first flange 34 and a first connecting pipe 35, wherein one end of the guide shoe 33 is tapered, the other end of the guide shoe 33 is cylindrical, the diameter of the cylindrical end of the guide shoe 33 is slightly smaller than that of the first bushing 31, the cylindrical end of the guide shoe 33 is located in the first bushing 31, the tapered end of the guide shoe 33 extends out of the bottom end of the first bushing 31, one end of the second bushing 32 is sleeved on the first bushing 31, cotton yarn 36 is wound on the male buckle ends of the second bushing 32 and the first bushing 31, and both the first bushing 31 and the second bushing 32 in this embodiment are oil bushings.

The other end of the second sleeve 32 is provided with a first flange 34, and one end of the first connecting pipe 35 is connected with the first flange 34, wherein the first flange 34 is installed in the prior art.

The working principle of the embodiment is as follows: drilling: the method comprises the steps of drilling by adopting a guide expanding drill bit, installing a centralizer at one end with threads of the guide expanding drill bit through threads, and then sequentially connecting the centralizers in a threaded manner to drill.

Tube laying: the guide shoe 33, the first sleeve 31 and the second sleeve 32 are sequentially placed in the drilled hole, then the first flange 34 and the first connecting pipe 35 are installed at the end of the second sleeve 32, and then grouting is performed into the first connecting pipe 35.

The beneficial effects of the embodiment are that: when the drilling and hole sealing tool in the embodiment is used for drilling, the guide expanding bit drills, the centralizer straightens the drilling track to ensure that the drilling track meets the pipe laying requirement, and the bulge 24 on the side wall of the centralizer main body can polish the place with unsmooth hole wall in the drilling process. And the opening difficulty is reduced.

Example 2

This embodiment is different from embodiment 1 in that: as shown in fig. 4, the drilling device further comprises a mud purification device, the mud purification device comprises a water tank 41, a sedimentation tank 42, a mud tank 43, a first mud suction pipe 44, a first mud pump 45 and a first mud discharge pipe 46, the water tank 41 is arranged near the drilled hole, so that the drilled mud flows into the water tank 41, the specific installation position of the water tank 41 is set according to the working conditions, the water tank 41 is communicated with the sedimentation tank 42, the sedimentation tank 42 is communicated with the mud tank 43, one end of the first mud suction pipe 44 is connected with the mud tank 43, the other end of the mud suction pipe is connected with the first mud pump 45, one end of the mud discharge pipe is connected with the first mud pump 45, and the other end of the mud discharge pipe is connected with one end of the second drill rod 23.

The working principle of the embodiment is as follows: the water tank 41 is arranged near the drilling hole, so that the slurry after drilling flows into the water tank 41, then flows into the sedimentation tank 42, is sedimentated through the sedimentation tank 42, useless solid phases such as rock debris and the like in the slurry are cleared, the slurry is prepared at any time, the performance of the slurry is maintained and stabilized, the sedimentated slurry is discharged into the slurry tank 43, is pumped into the slurry discharge pipe from the slurry suction pipe through the first slurry pump 45, and finally enters the second drill rod 23, so that the guiding reamer bit is used for hole sweeping.

The beneficial effects of the embodiment are that: the mud is circularly purified by the mud purifying device, the performance of the mud is kept and stabilized, and virtuous circle is achieved.

Example 3

A construction method for draining water downhole by using the downhole drilling and sealing tool of embodiment 1, comprising the steps of:

(1) using a first drill bit: drilling to 33m by using a phi 94mm composite sheet drill bit in cooperation with a phi 89mm rib drill rod, grouting under pressure after the drill is pulled out, and throwing 33m by using the phi 89mm rib drill rod in cooperation with the phi 94mm composite sheet drill bit after grout is solidified;

(2) front guide and rear centralizing and grading reaming: sequentially adopting a guiding reamer bit with phi 94mm changing into phi 153mm, phi 153mm changing into phi 196mm, phi 196mm changing into phi 248mm, and phi 248mm changing into phi 268mm, adding 5 centralizers on the front 10m drill rod close to the bottom of the hole in a manner of dense front and thin back for keeping straight, and performing graded reaming to 33 m. When using phi 268mm direction reamer bit, a centralizer of reaming installation for the first time, reaming two and two centralizers in the second time, reaming three and three centralizer in the third time. The hole is swept for multiple times by matching with a phi 89mm rib drill rod, and during hole sweeping, a large-pump-capacity slurry pump is used for matching with chemical slurry (the ratio of water to kaolin powder to sodium carbonate is 400 kg: 100 kg: 2 kg) to perform slurry circulation wall protection and slag discharge.

(3) And tracking and measuring the inclination. And the actual track of the drilling is tracked through inclination measurement, so that the drilling track meets the pipe laying requirement. And (5) circularly sweeping the hole wall and discharging slag.

(4) One opening and closing the tube: adopt rig and manual work mode, downthehole first sleeve pipe of phi 219mm oil casing, first sleeve pipe length is no less than 20m, and the wooden toper guide shoe of about 300m is established to first sleeve pipe bottom endotheca, twines the cotton yarn at the position of 300mm apart from drill way second sleeve pipe pin end, reserves a 2m long 4 minutes iron pipe 51 in the clearance between second sleeve pipe and drilling simultaneously, installs first ring flange and first connecting pipe at the sheathed tube tip of second.

(5) An opening and fixing pipe: before grouting and pipe fixing, drilling a penetrating guide shoe. And (3) filling and tamping an annular clearance with the aperture section of 800mm by using stirred thick cement (the water cement ratio is 0.5: 1). After solidification, connecting the pipeline, and performing grouting by adopting a circulating grouting method. Until the grouting pressure is not less than 4MPa and the pressure stabilizing time is not less than 30 minutes.

As shown in fig. 5, the circular grouting method is to fixedly connect an iron pipe 51 with a first grout outlet pipe 52, connect a first connecting pipe with one end of the first grout outlet pipe 53, connect the first grout outlet pipe 53 with an inlet end of a second mud pump 54, connect an outlet end of the second mud pump 54 with one end of a second grout inlet pipe 56, connect the other end of the second grout inlet pipe 56 with a grouting barrel 55, and connect the other end of the first grout outlet pipe 52 with the grouting barrel 55. The mud enters the second casing from the first slip casting pipe 53, and the iron pipe 51 serves as a mud return pipe.

(6) Secondly, forming a hole: using a first drill bit: drilling by matching a phi 94mm composite sheet drill bit with a phi 89mm rib drill rod, and if the drill bit does not return water before drilling to the designed hole depth, immediately tripping the drill bit; and if the drilling is carried out till the designed hole depth and the drilled hole returns water normally, continuing the construction for 3m-5m and reserving the drilled hole for use as the precipitated drilling cuttings.

After the drill is taken out, a preposed guiding expanding drill with phi 94mm changed into phi 153mm and with phi 153mm changed into phi 196mm is adopted for expanding the hole. During reaming construction, 5 centralizers are added on the front 10m drill rod close to the bottom of the hole in a mode of dense front and thin back to ensure straight reaming.

The mud circulation hole-sweeping dado uses a phi 196mm coreless drill bit, a phi 140mm centralizer (1 for the first time and 2 for the second time) is added, a phi 89mm rib drill rod is matched for hole-sweeping for multiple times, and chemical mud prepared from kaolin powder is used for circulation dado and slag discharge during hole-sweeping.

(7) Opening a lower pipe: as shown in fig. 6, according to the design hole depth, the third casing 58 includes a Φ 127mm petroleum flower casing and a Φ 177.8mm petroleum casing, and the Φ 127mm petroleum flower casing and the Φ 177.8mm petroleum casing are connected in a variable diameter manner, which is the prior art. And the diameter of the oil casing is not less than 17m, and the pipe orifice of the oil casing with the diameter of 177.8mm is provided with a second flange plate 57.

(8) Drilling a final hole: using a first drill bit: and (3) drilling the phi 94mm composite sheet drill bit to a penetrated goaf by matching with a phi 89mm rib drill rod, and performing pressure water slag discharge construction in the drilling process to clean slurry so as to prevent the drilling hole from being blocked due to slurry solidification.

By adopting the method in the embodiment, the one-opening and two-opening petroleum casing pipes are drilled and laid smoothly, 1-2 shifts are used, the one-opening casing pipe is laid for 23 m on average, the two-opening casing pipe is laid for 41.5 m on average, and the casing pipe fixing and pressure resistance test both meet the design requirements. The drilling machine is suitable for drilling holes, pipe descending and pipe fixing of underground large-diameter drainage water.

The above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.

Claims

1. The utility model provides a hole sealing instrument drills in pit which characterized in that: the device comprises a drilling device and a grouting sleeve device;

the drilling device comprises a guiding hole expanding drill bit and a plurality of centralizers, wherein one end of the guiding hole expanding drill bit is provided with an internal thread; the centralizer comprises a plurality of centralizers, a plurality of connecting rods and a plurality of connecting rods, wherein the plurality of centralizers are sequentially connected, each centralizer comprises a centralizer body, a first drill rod and a second drill rod, the centralizer bodies are cylindrical, and bulges are arranged on the outer side walls of the centralizer bodies;

the centralizer comprises a centralizer body, a first drill rod, a second drill rod and a control device, wherein the first drill rod and the second drill rod are respectively positioned at two ends of the centralizer body; one end of the guiding hole expanding drill bit is in threaded connection with one end of the first drill rod;

2. The downhole drilling and sealing tool of claim 1, wherein: the guiding reaming drill bit comprises a first guiding drill bit, a second guiding drill bit, a connecting rod and a reaming piece, the first guiding drill bit and the second guiding drill bit are both cylindrical, one end of the first guiding drill bit is connected with one end of the second guiding drill bit, the other end of the second guiding drill bit is connected with one end of the connecting rod, the other end of the connecting rod is provided with internal threads, and the first guiding drill bit, the second guiding drill bit and the connecting rod are sequentially communicated and coaxially arranged;

3. The downhole drilling and sealing tool of claim 1, wherein: the length of the first drill rod is equal to that of the second drill rod, and the diameter of the first drill rod is equal to that of the second drill rod.

4. The downhole drilling and sealing tool of claim 1, wherein: the underground drilling and hole sealing tool further comprises a slurry purifying device, wherein the slurry purifying device comprises a water tank, a sedimentation tank, a slurry tank, a first slurry suction pipe, a first slurry pump and a first slurry discharge pipe, the water tank is communicated with the sedimentation tank, the sedimentation tank is communicated with the slurry tank, one end of the first slurry suction pipe is connected with the slurry tank, the other end of the slurry suction pipe is connected with the first slurry pump, one end of the slurry discharge pipe is connected with the first slurry pump, and the other end of the slurry discharge pipe is connected with one end of a second drill rod.

5. A drainage construction method using the downhole drilling and sealing tool according to any one of claims 1 to 4, characterized by: the method comprises the following steps:

6. The drainage construction method of the downhole drilling and sealing tool according to claim 5, wherein: the first drill bit is a phi 94mm composite sheet drill bit, and the first drill bit is adopted to drill to 33m in the step (1).

7. The downhole drilling and sealing tool of claim 5, wherein: the number of direction reamer bit is four, direction reamer bit is reducing direction reamer bit, and the diameter of four reducing direction reamer bits is in proper order: phi 94mm to phi 153mm, phi 153mm to phi 196mm, phi 196mm to phi 248mm, and phi 248mm to phi 268 mm.

8. The downhole drilling and sealing tool of claim 5, wherein: the number of the centralizers is six, when the guiding reaming drill bit with the diameter of phi 268mm and the largest diameter is used, one centralizer is installed for primary reaming, two centralizers are added for secondary reaming, and three centralizers are added for tertiary reaming.