CN111322009B - A kind of downhole blowout prevention hole pressure maintaining drilling method - Google Patents
A kind of downhole blowout prevention hole pressure maintaining drilling method Download PDFInfo
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- CN111322009B CN111322009B CN202010181443.0A CN202010181443A CN111322009B CN 111322009 B CN111322009 B CN 111322009B CN 202010181443 A CN202010181443 A CN 202010181443A CN 111322009 B CN111322009 B CN 111322009B
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- 238000005553 drilling Methods 0.000 title claims abstract description 178
- 238000000034 method Methods 0.000 title claims abstract description 27
- 230000002265 prevention Effects 0.000 title claims abstract 7
- 239000007788 liquid Substances 0.000 claims abstract description 237
- 230000007246 mechanism Effects 0.000 claims abstract description 83
- 239000012530 fluid Substances 0.000 claims abstract description 81
- 238000003860 storage Methods 0.000 claims abstract description 31
- 239000011435 rock Substances 0.000 claims abstract description 29
- 238000005520 cutting process Methods 0.000 claims abstract description 15
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 43
- 238000007789 sealing Methods 0.000 claims description 35
- 239000003245 coal Substances 0.000 claims description 33
- 230000000903 blocking effect Effects 0.000 claims description 21
- 230000001681 protective effect Effects 0.000 claims description 7
- 230000008569 process Effects 0.000 claims description 6
- 238000009825 accumulation Methods 0.000 claims description 5
- 238000011084 recovery Methods 0.000 claims description 3
- 230000015572 biosynthetic process Effects 0.000 claims description 2
- 238000013022 venting Methods 0.000 claims 2
- 230000000630 rising effect Effects 0.000 claims 1
- 239000000203 mixture Substances 0.000 abstract description 3
- 238000012423 maintenance Methods 0.000 abstract 2
- 238000007664 blowing Methods 0.000 abstract 1
- 238000011065 in-situ storage Methods 0.000 abstract 1
- 230000032258 transport Effects 0.000 abstract 1
- 239000007789 gas Substances 0.000 description 33
- 238000007599 discharging Methods 0.000 description 19
- 239000008247 solid mixture Substances 0.000 description 6
- 239000007921 spray Substances 0.000 description 5
- 230000009471 action Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000012544 monitoring process Methods 0.000 description 2
- 239000002912 waste gas Substances 0.000 description 2
- NRTLIYOWLVMQBO-UHFFFAOYSA-N 5-chloro-1,3-dimethyl-N-(1,1,3-trimethyl-1,3-dihydro-2-benzofuran-4-yl)pyrazole-4-carboxamide Chemical compound C=12C(C)OC(C)(C)C2=CC=CC=1NC(=O)C=1C(C)=NN(C)C=1Cl NRTLIYOWLVMQBO-UHFFFAOYSA-N 0.000 description 1
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- 238000010992 reflux Methods 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
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- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B7/00—Special methods or apparatus for drilling
- E21B7/04—Directional drilling
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B17/00—Drilling rods or pipes; Flexible drill strings; Kellies; Drill collars; Sucker rods; Cables; Casings; Tubings
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- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B21/00—Methods or apparatus for flushing boreholes, e.g. by use of exhaust air from motor
- E21B21/01—Arrangements for handling drilling fluids or cuttings outside the borehole, e.g. mud boxes
- E21B21/015—Means engaging the bore entrance, e.g. hoods for collecting dust
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- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B21/00—Methods or apparatus for flushing boreholes, e.g. by use of exhaust air from motor
- E21B21/10—Valve arrangements in drilling-fluid circulation systems
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- Engineering & Computer Science (AREA)
- Life Sciences & Earth Sciences (AREA)
- Geology (AREA)
- Mining & Mineral Resources (AREA)
- Physics & Mathematics (AREA)
- Environmental & Geological Engineering (AREA)
- Fluid Mechanics (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geochemistry & Mineralogy (AREA)
- Mechanical Engineering (AREA)
- Earth Drilling (AREA)
Abstract
本发明公开了一种井下防喷孔保压钻孔方法，包括以下步骤：一、打钻封孔；二、安装防护管并连接钻井液保压回液机构；三、获取保压压力值；四、储液腔排气；五、保压钻孔；六、续杆排液；七、煤岩层的持续保压钻孔；八、保压回拆。本发明根据实际煤岩层地应力、钻孔围岩物理力学性质和瓦斯压力获取保压压力值，利用钻井液配合保压回液机构平衡钻孔内的压力，并利用高压回流管向钻井液保压回液机构输送钻孔间隙回流的气、液及钻屑混合物并排出，通过独立钻杆连接多节连接钻杆组成保压钻杆机构，实现钻孔保压，防止钻孔喷孔、坍塌及钻井液喷出。
The invention discloses a pressure-maintaining drilling method for downhole blowout prevention holes. 4. Exhausting the liquid storage chamber; 5. Drilling under pressure maintenance; The invention obtains the pressure-holding pressure value according to the in-situ stress of the actual coal-rock layer, the physical and mechanical properties of the surrounding rock of the drilled hole and the gas pressure, uses the drilling fluid to cooperate with the pressure-holding liquid return mechanism to balance the pressure in the drilled hole, and uses the high-pressure return pipe to maintain the pressure of the drilling fluid to the drilling fluid. The pressure-returning mechanism transports the gas, liquid and drill cuttings mixture backflowing from the drilling gap and discharges it. The pressure-maintaining drill-pipe mechanism is formed by connecting the independent drill pipe with the multi-joint drill pipe, so as to realize the pressure maintenance of the drilling hole and prevent the drilling hole from blowing out and collapsing. and drilling fluid ejection.
Description
Technical Field
The invention belongs to the technical field of pressure-maintaining drilling of underground blowout-preventing holes, and particularly relates to a pressure-maintaining drilling method of underground blowout-preventing holes.
Background
When a coal rock layer with high gas content and high gas pressure is drilled in a coal mine, along with the exposure of a coal body of a drill hole, the stress of the coal rock body on the wall of the drill hole is redistributed, the pressure in the drill hole is lower, high-pressure gas and other gas in the coal rock layer enter the drill hole, the coal body is easy to spray holes and even is induced to protrude under the combined action of the gas pressure, the ground stress and the disturbance stress of the drill hole, the sprayed coal wastes resources and influences the operation environment along with water flow, and meanwhile, the holes formed by the spray holes have larger holes, influence the forming and stability of the drill hole, and are unfavorable for the later-stage fracturing and other methods to change the fracture of the coal rock body, so; the operation safety is influenced by the mixture of gas, coal, drilling fluid and drill cuttings which are sprayed out through the induction of the uncontrollable spray holes, and the gas is easily over-limited due to the fact that a large amount of gas and other gas are gushed out, so that accidents such as gas suffocation and gas explosion are easily caused. When adopting the rig drilling in the pit in the colliery, current drilling can't cooperate drilling fluid balanced borehole internal pressure, and when withdrawing the brill, the drilling fluid that injects before can the orifice, and the orifice changes the coal petrography body wholeness, increases and digs the roof management degree of difficulty to influence safety in production. When drilling in weak rock, the collapse of the drilled hole is easily caused under the combined action of the ground stress and the disturbance stress of the drilled hole, and the stability and the forming of the drilled hole are influenced.
Disclosure of Invention
The technical problem to be solved by the invention is to provide an underground anti-jet hole pressure-maintaining drilling method aiming at the defects in the prior art, a pressure-maintaining pressure value is obtained according to an actual coal rock layer, a drilling fluid pressure-maintaining liquid returning mechanism is used for balancing the pressure inside and outside a drilled hole, a high-pressure return pipe is used for conveying a gas, liquid and solid mixture returned from a drilling hole clearance to the drilling fluid pressure-maintaining liquid returning mechanism and discharging the gas, liquid and solid mixture, and a plurality of sections of connected drill rods are connected through independent drill rods to form a drill rod, so that the drilling pressure maintaining is realized, the drilling.
In order to solve the technical problems, the invention adopts the technical scheme that: a pressure-maintaining drilling method for a downhole blowout-preventing hole is characterized by comprising the following steps:
step one, drilling and sealing holes: drilling at a design position according to a design azimuth angle and a design inclination angle by using a drilling machine and an initial drill rod mechanism which is matched with the drilling machine and extends into a coal rock layer until the drilling depth reaches the design depth, wherein the design depth is equal to the length of a hole sealing section, and the length of the initial drill rod mechanism is not less than the length of the hole sealing section;
the initial drill rod mechanism comprises an independent drill rod, a drill bit arranged on the front side of the independent drill rod and a connecting drill rod assembly arranged on the rear side of the independent drill rod, wherein the connecting drill rod assembly comprises N connecting drill rods which are sequentially connected, and N is a positive integer;
the independent drill rod comprises a hollow rod body, a spring baffle table and a pressure maintaining ball baffle table, wherein the spring baffle table and the pressure maintaining ball baffle table are arranged in the rod body, a liquid passing cavity is formed in a space between the spring baffle table and the pressure maintaining ball baffle table, a pressure maintaining spring and a pressure maintaining ball matched with the pressure maintaining spring are arranged in the liquid passing cavity, a spring baffle table water through hole communicated with the liquid passing cavity is formed in the spring baffle table, a pressure maintaining ball baffle table water through hole communicated with the liquid passing cavity is formed in the pressure maintaining ball baffle table, the spring baffle table is arranged on one side, close to the drill bit, of the rod body, the drill bit is connected with the rod body through the rod head, and a connecting hole communicated with the pressure maintaining ball baffle table water;
the connecting drill rod comprises an independent drill rod and a drill rod connector which is arranged at the front end of the independent drill rod and is of a hollow structure, a pressure maintaining ball ejector rod is arranged at the front end of the drill rod connector, and a drill rod head water through hole communicated with the independent drill rod is formed in the pressure maintaining ball ejector rod;
step two, mounting a protective pipe and connecting a drilling fluid pressure maintaining and returning mechanism: installing and connecting a drill rod at the rear side of the initial drill rod mechanism, prolonging the initial drill rod mechanism, changing the initial drill rod mechanism into a real-time drill rod mechanism, when the drilling length of the real-time drill rod mechanism is equal to the sum of the lengths of the hole sealing section, the high-pressure guide pipe and the sleeve, sleeving the high-pressure guide pipe at one end of the real-time drill rod mechanism, which extends out of the coal rock layer, and hermetically connecting the high-pressure guide pipe with the hole sealing section, arranging the sleeve at one end of the high-pressure guide pipe, which is far;
a drilling gap communicated with the high-pressure guide pipe is formed between the real-time drill rod mechanism and the inner wall of a drill hole, and the high-pressure guide pipe is connected with a high-pressure return pipe communicated with the drilling fluid pressure maintaining liquid return mechanism;
the drilling fluid pressure maintaining liquid returning mechanism comprises a pressure maintaining liquid returning container, a pressure maintaining piston arranged in the pressure maintaining liquid returning container and a liquid accumulating pool arranged beside the pressure maintaining liquid returning container and communicated with the pressure maintaining liquid returning container, wherein a space of the pressure maintaining liquid returning container, which is positioned at the lower side of the pressure maintaining piston, is a liquid storage cavity, a space of the pressure maintaining liquid returning container, which is positioned at the upper side of the pressure maintaining piston, is a pressure maintaining liquid cavity, a liquid drainage liquid inlet pipe is arranged at the bottom of the pressure maintaining liquid returning container, a liquid drainage liquid inlet control valve is arranged on the liquid drainage liquid inlet pipe, a first high-pressure exhaust pipe, a safety pressure relief valve and a pressure maintaining liquid inlet pipe are arranged at the top of the pressure maintaining liquid returning container, a check valve is arranged on the pressure maintaining liquid inlet pipe, a high-pressure gas returning hole is formed in the pressure maintaining piston, the high-pressure, the depth indicating rod extends into the pressure maintaining liquid returning container and is connected with the pressure maintaining piston, a pressure gauge is installed at the top of the depth indicating rod, a liquid discharging and liquid discharging pipe is further arranged at the bottom of the pressure maintaining liquid returning container, the pressure maintaining liquid returning container is communicated with a liquid accumulating pool through the liquid discharging and liquid discharging pipe, a liquid discharging and liquid discharging control valve is installed on the liquid discharging and liquid discharging pipe, and the height of the liquid discharging and liquid discharging pipe is higher than that of a liquid discharging and liquid feeding pipe;
step three, according to the formula P ═ kP1Obtaining a pressure maintaining pressure value P, wherein k is a safety factor, P1Compensating the radial stress value of the formation pressure for the drilling fluid;
step four, exhausting gas from the liquid storage cavity: filling pressure maintaining liquid from the pressure maintaining liquid inlet pipe, enabling the pressure maintaining liquid to enter a pressure maintaining liquid cavity through a one-way valve to push a pressure maintaining piston, enabling the pressure maintaining piston to move downwards to discharge gas in a liquid storage cavity to a waste gas recovery system through a high-pressure gas return hole in the pressure maintaining piston, a second high-pressure exhaust pipe and a first high-pressure exhaust pipe until the position of the depth indicating rod does not move any more and a pressure value displayed by a pressure gauge is unchanged, stopping filling the pressure maintaining liquid, and finishing the exhaust of the liquid storage cavity;
step five, pressure maintaining and drilling, wherein the process is as follows:
step 501, adjusting the pressure value of the safety relief valve to be a pressure maintaining pressure value P, and monitoring the pressure maintaining pressure value in the pressure maintaining hydraulic cavity in real time through a pressure gauge;
502, connecting a new connecting drill rod behind the real-time drill rod mechanism, updating the real-time drill rod mechanism, ejecting a pressure maintaining ball from a pressure maintaining ball baffle table by a pressure maintaining ball ejector rod of the connecting drill rod, injecting a drilling fluid with pressure P into the updated real-time drill rod mechanism through a drilling machine, enabling the drilling fluid to flow through a connecting hole and a water through hole of the pressure maintaining ball baffle table in the new connecting drill rod, enabling the drilling fluid to flow through a gap between the pressure maintaining ball and a liquid through cavity, then flow into the previous drill rod through a water through hole and a rod head of a spring baffle table until the drilling fluid is conveyed to a drill bit to enter a coal rock stratum, enabling the drilling fluid mixed drilling cuttings and gas to flow back to a high-pressure guide pipe, and enabling the drilling fluid mixed drilling cuttings and gas to flow back through a high-pressure return pipe to a liquid storage cavity, and pushing the pressure maintaining piston to move upwards along with the backflow of the drilling fluid mixed cuttings and gas, when the pressure of the pressure maintaining liquid cavity is greater than the pressure maintaining value Upward movement is carried out, and pressure maintaining drilling is realized;
step six, continuous rod liquid discharge: when a drill rod is connected, the drilling machine retreats after stopping drilling, high-pressure drilling fluid flows back, the pressure maintaining spring pushes the pressure maintaining ball to reset, the pressure maintaining ball abuts against the pressure maintaining ball baffle table to plug a water through hole of the pressure maintaining ball baffle table, and the real-time drill rod mechanism realizes drill stopping, pressure maintaining and drill rod sealing; simultaneously closing a liquid drainage and liquid inlet control valve, adopting the liquid storage cavity exhaust process in the fourth step to exhaust gas brought out by well drilling fluid mixed drilling cuttings, closing an exhaust valve after the exhaust is finished, opening a liquid drainage and liquid outlet control valve, filling pressure maintaining liquid into a pressure maintaining liquid cavity, pushing a pressure maintaining piston to move downwards by the pressure maintaining liquid, and enabling the drilling fluid mixed drilling cuttings in the liquid storage cavity to flow into a liquid accumulating pool through a liquid drainage and liquid outlet pipe;
step seven, the step five to the step six are circulated for multiple times, and continuous pressure maintaining drilling of the coal rock stratum is achieved;
step eight, pressure maintaining and dismantling: when the real-time drill rod withdrawing mechanism withdraws the drill, drilling fluid is continuously injected into the drill hole, and the drill is withdrawn at the same time, so that the pressure in the drill hole is prevented from suddenly dropping, and the pressure maintaining and drill withdrawal are realized.
The pressure maintaining drilling method for the underground blowout preventing hole is characterized by comprising the following steps of: and the safety coefficient k in the third step is 1.2-1.5.
The pressure maintaining drilling method for the underground blowout preventing hole is characterized by comprising the following steps of: the high-pressure return pipe is communicated with the liquid discharge and liquid inlet pipe through a pressure maintaining liquid return pipe, and a return valve is installed on the high-pressure return pipe.
The pressure maintaining drilling method for the underground blowout preventing hole is characterized by comprising the following steps of: the outer diameter of the pressure maintaining ball is larger than the inner diameter of a water through hole of the pressure maintaining ball blocking table, the outer diameter of the pressure maintaining ball is larger than the inner diameter of a pressure maintaining spring, the outer diameter of the pressure maintaining spring is larger than the inner diameter of the water through hole of the spring blocking table, the outer diameter of a push rod of the pressure maintaining ball is smaller than the inner diameter of the water through hole of the pressure maintaining ball blocking table, and an inner thread is arranged on the inner wall of the connecting hole.
The pressure maintaining drilling method for the underground blowout preventing hole is characterized by comprising the following steps of: and external threads are arranged outside the drill rod connector.
Compared with the prior art, the invention has the following advantages:
1. the invention determines the length of the hole sealing section by drilling and sealing holes and seals the holes, prepares for installing a protective pipe and connecting a drilling fluid pressure maintaining and liquid returning mechanism, a drill rod is installed and connected at the rear side of the initial drill rod mechanism, the initial drill rod mechanism is extended, when the length of the real-time drill rod mechanism is equal to the sum of the lengths of the hole sealing section, the high-pressure guide pipe and the sleeve, the high-pressure guide pipe is sleeved at one end of the real-time drill rod mechanism, which extends out of the coal rock layer, and is hermetically connected with the hole sealing section, one end of the high-pressure flow guide pipe, which is far away from the hole sealing section, is provided with a sleeve, the high-pressure flow guide pipe in the protective pipe recovers gas, liquid and solid mixtures which flow back from the clearance of the drilled hole, and the pressure inside and outside the drill hole is effectively adjusted by transmitting the pressure to the drilling fluid pressure maintaining and liquid returning mechanism through the high-pressure return pipe, and one end of the high-pressure flow guide pipe, which is far away from the hole sealing section, is provided with a sleeve, so that the friction between the drill rod and the high-pressure flow guide pipe is reduced while sealing is realized, and the drilling fluid pressure maintaining and liquid returning mechanism.
2. According to the invention, the pressure maintaining pressure value is obtained according to the actual coal rock stratum, the pressure maintaining piston in the drilling fluid pressure maintaining liquid returning mechanism divides the pressure maintaining liquid returning container into the liquid storage cavity and the pressure maintaining liquid cavity, the pressure maintaining liquid cavity is provided with the pressure maintaining liquid cavity through the safety pressure relief valve, the pressure inside and outside the drill hole is balanced, the phenomenon that the pressure inside and outside the drill hole is unbalanced to cause the spray hole is avoided, the pressure maintaining piston is provided with the high-pressure air returning hole, the gas recovered from the liquid storage cavity is released, the liquid recovered from the liquid storage cavity is collected by the liquid accumulating tank and is conducted in a reciprocating mode, the pressure maintaining drill hole is realized, the safety and the reliability are realized, the moving position of the pressure maintaining piston is visually displayed by the depth indicating rod.
3. The independent drill rod and the connecting drill rod are both limited in the rod body by arranging the spring blocking table and the pressure maintaining ball blocking table, the spring blocking table is provided with a spring blocking table water through hole, the pressure maintaining ball blocking table is provided with a pressure maintaining ball blocking table water through hole, so that drilling fluid can be smoothly poured into a coal seam layer, the pressure maintaining ball is arranged at one end of the rod body far away from a drill bit, when a drilling machine drills, the drilling machine pushes the pressure maintaining ball to separate the pressure maintaining ball from the pressure maintaining ball blocking table, the drilling fluid enters a liquid through hole through the pressure maintaining ball blocking table water through hole and flows out of the rod body through the spring blocking table water through hole, so that the drilling fluid is smoothly poured, when the drilling machine retreats, the pressure maintaining ball retreats to the position of the pressure maintaining ball blocking table to block the pressure maintaining ball blocking table water through hole, so that drilling pressure maintaining is realized, drilling fluid spraying holes are prevented, safety and reliability are realized, each connecting drill rod is connected, a connecting rod on the connecting rod is in the connecting rod, the connecting head on the The ball ensures a hollow channel of the drill rod, and facilitates the circulation of drilling fluid.
4. The method has simple steps, realizes the continuous pressure-maintaining drilling of the coal rock layer by performing pressure-maintaining drilling and continuous rod liquid drainage repeatedly, is safe and reliable, prevents the drilling hole from losing pressure due to drilling fluid jet holes, and is convenient to popularize and use.
In summary, the invention obtains the pressure maintaining pressure value according to the actual coal rock layer, utilizes the drilling fluid pressure maintaining and liquid returning mechanism to balance the pressure inside and outside the drill hole, utilizes the high-pressure return pipe to convey the gas, liquid and solid mixture flowing back from the drill hole gap to the drilling fluid pressure maintaining and liquid returning mechanism and discharge the mixture, and connects a plurality of sections of connecting drill rods through independent drill rods to form the drill rod, thereby realizing the pressure maintaining of the drill hole, preventing the pressure loss of the drill hole caused by the spray holes of the drilling fluid, and being.
The technical solution of the present invention is further described in detail by the accompanying drawings and embodiments.
Drawings
FIG. 1 is a schematic diagram of the fit relationship between the drill rod mechanism and the drilling fluid pressure maintaining and returning mechanism of the present invention.
Fig. 2 is a schematic structural view of the stand-alone drill rod of the present invention.
Fig. 3 is a schematic structural view of the connecting drill rod of the present invention.
FIG. 4 is a block diagram of a method flow of the present invention.
Description of reference numerals:
1-a drill bit; 2-independent drill pipe; 2-1-rod body;
2-club head; 2-3-spring block platform; 2-4-a water through hole of the spring blocking platform;
2-5-liquid through cavity; 2-6-pressure maintaining spring; 2-7-pressure maintaining ball;
2-8-pressure maintaining ball blocking table; 2-9-a water through hole of the pressure maintaining ball blocking table;
2-10-connecting hole; 3, connecting a drill rod; 3-1-pressure maintaining ball ejector rod;
3-2-drill rod connector; 3-drill rod head limber hole; 4, sealing the hole section;
5-high pressure honeycomb duct; 6-high pressure return pipe; 6-1-pressure maintaining liquid return pipe;
6-2-reflux valve; 7-drilling fluid pressure maintaining and returning mechanism;
7-1-a liquid storage cavity; 7-2-pressure maintaining liquid cavity; 7-3-pressure maintaining piston;
7-4-high pressure air return hole; 7-5-a second high-pressure exhaust pipe; 7-6 — a first high pressure exhaust pipe;
7-safety relief valve; 7-8-pressure maintaining liquid inlet pipe; 7-9-liquid discharging and feeding pipe;
7-10-liquid discharge and liquid outlet pipe; 7-11-liquid drainage and liquid inlet control valve;
7-12-liquid discharge control valve; 7-13-depth indicating rod;
7-14-pressure gauge; 7-15-exhaust valve; 7-16-liquid collecting tank;
7-17-one-way valve; 8, a drilling machine; 9-coal rock layer;
10-a sleeve; 11-drill hole clearance.
Detailed Description
As shown in fig. 1 to 4, the downhole blowout-preventing hole pressure-maintaining drilling method of the invention comprises the following steps:
step one, drilling and sealing holes: drilling at a design position according to a design azimuth angle and a design inclination angle by using a drilling machine 8 and an initial drill rod mechanism which is matched with the drilling machine 8 and extends into a coal rock layer 9 until the drilling depth reaches the design depth, wherein the design depth is equal to the length of a hole sealing section 4, and the length of the initial drill rod mechanism is not less than the length of the hole sealing section 4;
the initial drill rod mechanism comprises an independent drill rod 2, a drill bit 1 arranged on the front side of the independent drill rod 2 and a connecting drill rod assembly arranged on the rear side of the independent drill rod 2, wherein the connecting drill rod assembly comprises N connecting drill rods 3 which are sequentially connected, and N is a positive integer;
the independent drill rod 2 comprises a hollow rod body 2-1, a spring baffle table 2-3 and a pressure maintaining ball baffle table 2-8, the spring baffle table 2-3 and the pressure maintaining ball baffle table 2-8 are arranged in the rod body 2-1, a liquid passing cavity 2-5 is formed in the space between the spring baffle table 2-3 and the pressure maintaining ball baffle table 2-8, a pressure maintaining spring 2-6 and a pressure maintaining ball 2-7 matched with the pressure maintaining spring 2-6 are arranged in the liquid passing cavity 2-5, a spring baffle table water through hole 2-4 communicated with the liquid passing cavity 2-5 is formed in the spring baffle table 2-3, a pressure maintaining ball baffle table water through hole 2-9 communicated with the liquid passing cavity 2-5 is formed in the pressure maintaining ball baffle table 2-8, the spring baffle table 2-3 is arranged on one side, close to the drill bit 1, the drill bit 1 is connected with the rod body 2-1 through a rod head 2-, one end of the rod body 2-1, which is far away from the drill bit 1, is provided with a connecting hole 2-10 communicated with a water through hole 2-9 of the pressure maintaining ball baffle table;
the connecting drill rod 3 comprises an independent drill rod 2 and a drill rod connector 3-2 which is arranged at the front end of the independent drill rod 2 and is of a hollow structure, a pressure maintaining ball ejector rod 3-1 is arranged at the front end of the drill rod connector 3-2, and a drill rod head water through hole 3-3 communicated with the independent drill rod 2 is formed in the pressure maintaining ball ejector rod 3-1;
the pressure maintaining spring 2-6 and the pressure maintaining ball 2-7 are limited in the rod body 2-1 by arranging the spring baffle table 2-3 and the pressure maintaining ball baffle table 2-8, the spring baffle table 2-3 is provided with the spring baffle table water through hole 2-4, and the pressure maintaining ball baffle table 2-8 is provided with the pressure maintaining ball baffle table water through hole 2-9, so that the drilling fluid can be smoothly poured into the coal rock layer 9; the pressure-maintaining ball 2-7 is arranged at one end of the rod body 2-1 far away from the drill bit 1, when the drilling machine 8 drills, the drilling machine 8 is matched with a pressure-maintaining ball ejector rod 3-1 to push the pressure-maintaining ball 2-7, so that the pressure-maintaining ball 2-7 is separated from a pressure-maintaining ball baffle table 2-8, drilling fluid enters a fluid through cavity 2-5 through a water through hole 2-9 of the pressure-maintaining ball baffle table and flows out of the rod body 2-1 through a water through hole 2-4 of a spring baffle table, smooth filling of the drilling fluid is ensured, when the drilling is retreated, the pressure-maintaining ball 2-7 returns to the position of the pressure-maintaining ball baffle table 2-8, the water through hole 2-9 of the pressure-maintaining ball baffle table is blocked, the pressure maintaining of the drilling hole is; when one section of connecting drill rod 3 is connected, a drill rod connector 3-2 on the connecting drill rod 3 is in threaded fit with a connecting hole 2-10 in the previous section, and a pressure maintaining ball ejector rod 3-1 on the front side of the drill rod connector 3-2 pushes a pressure maintaining ball 2-7 in the previous section of drill rod, so that a hollow channel of the drill rod is ensured, and the circulation of drilling fluid is facilitated.
Step two, mounting a protective pipe and connecting a drilling fluid pressure maintaining and returning mechanism: the method comprises the following steps that a connection drill rod 3 is installed on the rear side of an initial drill rod mechanism, the initial drill rod mechanism is extended, the initial drill rod mechanism is changed into a real-time drill rod mechanism, when the drilling length of the real-time drill rod mechanism is equal to the sum of the lengths of a hole sealing section 4, a high-pressure guide pipe 5 and a sleeve 10, the high-pressure guide pipe 5 is sleeved at one end, extending out of a coal rock layer 9, of the real-time drill rod mechanism and is in sealing connection with the hole sealing section 4, the sleeve 10 is arranged at one end, far away from the hole sealing section 4, of the high-pressure guide;
a drilling gap 11 communicated with the high-pressure guide pipe 5 is formed between the real-time drill rod mechanism and the inner wall of a drill hole, and the high-pressure guide pipe 5 is connected with a high-pressure return pipe 6 communicated with the drilling fluid pressure maintaining and returning mechanism 7;
the drilling fluid pressure maintaining liquid returning mechanism 7 comprises a pressure maintaining liquid returning container, a pressure maintaining piston 7-3 arranged in the pressure maintaining liquid returning container and a liquid accumulating pool 7-16 arranged beside the pressure maintaining liquid returning container and communicated with the pressure maintaining liquid returning container, the space of the pressure maintaining liquid returning container, which is positioned at the lower side of the pressure maintaining piston 7-3, is a liquid storing cavity 7-1, the space of the pressure maintaining liquid returning container, which is positioned at the upper side of the pressure maintaining piston 7-3, is a pressure maintaining liquid cavity 7-2, the bottom of the pressure maintaining liquid returning container is provided with a liquid discharging liquid inlet pipe 7-9, the liquid discharging liquid inlet pipe 7-9 is provided with a liquid discharging and inlet control valve 7-11, the top of the pressure maintaining liquid returning container is provided with a first high-pressure exhaust pipe 7-6, a safety pressure relief valve 7-7 and a pressure maintaining liquid inlet pipe 7-8, and the pressure maintaining liquid inlet pipe, a high-pressure air return hole 7-4 is arranged on the pressure maintaining piston 7-3, the high-pressure air return hole 7-4 is communicated with a first high-pressure exhaust pipe 7-6 through a second high-pressure exhaust pipe 7-5, an exhaust valve 7-15 is arranged on the first high-pressure exhaust pipe 7-6, a depth indicating rod 7-13 extends into the pressure maintaining liquid return container and is connected with a pressure maintaining piston 7-3, the top of the depth indicating rod 7-13 is provided with a pressure gauge 7-14, the bottom of the pressure maintaining liquid returning container is also provided with a liquid discharging and discharging pipe 7-10, the pressure maintaining liquid return container is communicated with the liquid accumulation pool 7-16 through a liquid discharge and liquid outlet pipe 7-10, a liquid discharge control valve 7-12 is arranged on the liquid discharge pipe 7-10, the height of the liquid discharge and liquid outlet pipe 7-10 is higher than that of the liquid discharge and liquid inlet pipe 7-9;
it is to be noted that the length of the hole sealing section 4 is determined by drilling and sealing holes, and the holes are sealed, so as to prepare for installing a protective pipe and connecting a drilling fluid pressure maintaining and liquid returning mechanism, a connecting drill rod 3 is arranged at the rear side of the initial drill rod mechanism, the initial drill rod mechanism is extended, when the length of the real-time drill rod mechanism is equal to the sum of the lengths of the hole sealing section 4, the high-pressure guide pipe 5 and the sleeve 10, the high-pressure guide pipe 5 is sleeved at one end of the real-time drill rod mechanism, which extends out of the coal rock layer 9, and is hermetically connected with the hole sealing section 4, one end of the high-pressure flow guide pipe 5, which is far away from the hole sealing section 4, is provided with a sleeve 10, the high-pressure flow guide pipe 5 in the protective pipe recovers gas, liquid and solid mixtures which flow back from the gaps of the drilled holes, the drilling fluid is transmitted to a drilling fluid pressure maintaining and returning mechanism 7 through a high-pressure return pipe 6, the pressure inside and outside the drilled hole is effectively adjusted, and a sleeve 10 is arranged at one end of the high-pressure guide pipe 5, which is far away from the hole sealing section 4, so that the friction between the independent drill rod 2 and the high-pressure guide pipe 5 is reduced while sealing is realized; a pressure maintaining piston 7-3 in the drilling fluid pressure maintaining liquid returning mechanism 7 divides a pressure maintaining liquid returning container into a liquid storage cavity 7-1 and a pressure maintaining liquid cavity 7-2, the pressure maintaining liquid cavity 7-2 is provided with pressure of the pressure maintaining liquid cavity 7-2 through a safety pressure relief valve 7-7, pressure inside and outside a drilled hole is balanced, pressure unbalance inside and outside the drilled hole is avoided, and a jet hole is formed, a high-pressure air returning hole 7-4 is formed in the pressure maintaining piston 7-3, gas recovered in the liquid storage cavity 7-1 is released, liquid recovered in the liquid storage cavity 7-1 is collected by a liquid accumulating tank 7-16 and is conducted in a reciprocating mode, pressure maintaining drilling is achieved, safety and reliability are achieved, the moving position of the pressure maintaining piston 7-3 is visually displayed by a depth indicating rod 7-13, the pressure maintaining piston 7-3 is prevented from extruding a second high-pressure.
During actual use, the height of the discharged liquid outlet pipe 7-10 is higher than that of the discharged liquid inlet pipe 7-9, so that a certain volume of liquid is kept in the pressure maintaining liquid return container, the liquid is prevented from flowing into the liquid accumulation tank 7-16 through the discharged liquid outlet pipe 7-10 completely, the downward moving position of the pressure maintaining piston 7-3 is limited, and the pressure maintaining piston 7-3 is prevented from moving downwards to the bottom of the pressure maintaining liquid return container to block the discharged liquid inlet pipe 7-9, so that the pressure maintaining failure of the drilling fluid pressure maintaining liquid return mechanism 7 is avoided.
Step three, according to the formula P ═ kP1Obtaining a pressure maintaining pressure value P, wherein k is a safety factor, P1Compensating for drilling fluidsRadial stress value of the layer pressure;
in the embodiment, the safety coefficient k in the third step is 1.2-1.5, and the safety coefficient k under the conditions that the drilling surrounding rock is relatively soft, the gas pressure is relatively large and the drilling distance is relatively long is relatively large.
Step four, exhausting gas from the liquid storage cavity: injecting pressure maintaining liquid from a pressure maintaining liquid inlet pipe 7-8, enabling the pressure maintaining liquid to enter a pressure maintaining liquid cavity 7-2 through a one-way valve 7-17 to push a pressure maintaining piston 7-3, enabling the pressure maintaining piston 7-3 to move downwards, enabling gas in a liquid storage cavity 7-1 to be discharged to a waste gas recovery system through a high-pressure air return hole 7-4 in the pressure maintaining piston 7-3, a second high-pressure exhaust pipe 7-5 and a first high-pressure exhaust pipe 7-6 until the position of a depth indicating rod 7-13 does not move any more and a pressure value displayed by a pressure gauge 7-14 is unchanged, stopping injecting the pressure maintaining liquid, and completing the exhaust of the liquid storage cavity 7-1;
step five, pressure maintaining and drilling, wherein the process is as follows:
step 501, adjusting the pressure value of the safety relief valve 7-7 to be a pressure maintaining pressure value P, and monitoring the pressure maintaining pressure value in the pressure maintaining liquid cavity 7-2 in real time through a pressure gauge 7-14;
step 502, connecting a new section of connecting drill rod 3 behind the real-time drill rod mechanism, updating the real-time drill rod mechanism, ejecting a pressure maintaining ball 2-7 away from a pressure maintaining ball baffle table 2-8 by a pressure maintaining ball ejector rod 3-1 of the connecting drill rod 3, injecting drilling fluid with pressure P into the updated real-time drill rod mechanism through a drilling machine 8, enabling the drilling fluid to enter the previous section of drill rod through a connecting hole 2-10 and a pressure maintaining ball baffle table water through hole 2-9 in the new connecting drill rod 3, enabling the drilling fluid to pass through a gap between the pressure maintaining ball 2-7 and a liquid through cavity 2-5, then entering the previous section of drill rod through a spring baffle table water through hole 2-4 and a rod head 2-2 until the drilling fluid is conveyed to a drill bit 1 to enter a coal rock layer 9, enabling drilling fluid mixed drilling cuttings and gas to flow back through a drilling hole gap 11, flowing back to a high-pressure guide pipe 5 to enter a liquid storage cavity 7-, the pressure in the liquid storage cavity 7-1 is continuously increased to push the pressure maintaining piston 7-3 to move upwards, when the pressure in the pressure maintaining liquid cavity 7-2 is greater than the pressure maintaining pressure value, the safety pressure relief valve 7-7 is opened, the drilling fluid mixed drilling cuttings in the liquid storage cavity 7-1 and the gas keep the pressure maintaining pressure value P to push the pressure maintaining piston 7-3 to continuously move upwards, and pressure maintaining drilling is achieved;
step six, continuous rod liquid discharge: when a drill rod is continued, the drill 8 retreats after stopping drilling, high-pressure drilling fluid flows back, the pressure maintaining springs 2-6 push the pressure maintaining balls 2-7 to reset, the pressure maintaining balls 2-7 abut against the pressure maintaining ball baffle table 2-8 to block the water through holes 2-9 of the pressure maintaining ball baffle table, and the real-time drill rod mechanism realizes drill stopping, pressure maintaining and drill rod sealing; simultaneously closing a discharged liquid inlet control valve 7-11, adopting a liquid storage cavity exhaust process in the fourth step, discharging gas carried by a well-drilling liquid mixed drilling cutting object, closing an exhaust valve 7-15 after the exhaust is finished, opening a discharged liquid outlet control valve 7-12, filling pressure maintaining liquid into a pressure maintaining liquid cavity 7-2, pushing a pressure maintaining piston 7-3 to move downwards by the pressure maintaining liquid, and allowing the drilling liquid mixed drilling cuttings in the liquid storage cavity 7-1 to flow into a liquid accumulating tank 7-16 through a discharged liquid outlet pipe 7-10;
step seven, the step five to the step six are circulated for multiple times, and continuous pressure maintaining drilling of the coal rock layer 9 is achieved;
during the in-service use, pressurize drilling and continuous pole flowing back are reciprocal to be gone on, realize the continuous pressurize drilling of coal petrography, and safe and reliable prevents that drilling fluid orifice from resulting in the drilling decompression.
Step eight, pressure maintaining and dismantling: when the real-time drill rod withdrawing mechanism withdraws the drill, drilling fluid is continuously injected into the drill hole, and the drill is withdrawn at the same time, so that the pressure in the drill hole is prevented from suddenly dropping, and the pressure maintaining and drill withdrawal are realized.
In this embodiment, the high-pressure return pipe 6 is communicated with the liquid discharge and inlet pipe 7-9 through the pressure maintaining return pipe 6-1, the return valve 6-2 is installed on the high-pressure return pipe 6, the return valve 6-2 is normally open, and the return valve 6-2 is closed when the pressure maintaining return pipe 6-1 is replaced.
In the embodiment, the outer diameter of the pressure retaining ball 2-7 is larger than the inner diameter of the pressure retaining ball baffle table water through hole 2-9, so as to ensure the effective blocking limit of the pressure retaining ball 2-7 by the pressure retaining ball baffle table 2-8, the outer diameter of the pressure retaining ball 2-7 is larger than the inner diameter of the pressure retaining spring 2-6, so as to ensure the effective extrusion of the pressure retaining ball 2-7 and the pressure retaining spring 2-6, the outer diameter of the pressure retaining spring 2-6 is larger than the inner diameter of the spring baffle table water through hole 2-4, so as to ensure the effective blocking limit of the pressure retaining spring 2-6 by the spring baffle table 2-3, the outer diameter of the pressure retaining ball ejector rod 3-1 is smaller than the inner diameter of the ball baffle table water through hole 2-9, so as to facilitate the pressure retaining ball ejector rod 3-1 to extend into the pressure retaining ball baffle table water through hole 2, in practical use, the length of the pressure maintaining ball ejector rod 3-1 can ensure that the pressure maintaining ball 2-7 is ejected away from the pressure maintaining ball baffle table 2-8, and the inner wall of the connecting hole 2-10 is provided with an internal thread.
In the embodiment, the drill rod connector 3-2 is externally provided with external threads which are convenient to match with the internal threads on the inner wall of the hole of the connecting hole 2-10.
When the drilling fluid pressure maintaining and returning mechanism is used, the pressure maintaining pressure value is obtained according to the actual coal rock stratum, the pressure inside and outside a drill hole is balanced by the drilling fluid pressure maintaining and returning mechanism, the gas, liquid and solid mixture flowing back from the drill hole gap is conveyed to the drilling fluid pressure maintaining and returning mechanism by the high-pressure return pipe and discharged, the independent drill rod is connected with a plurality of sections of connecting drill rods to form the drill rod, the drilling pressure maintaining is realized, and the drilling fluid orifice is prevented from causing the collapse of the drill hole or inducing the orifice of the drill hole and.
The above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention, and all simple modifications, changes and equivalent structural changes made to the above embodiment according to the technical spirit of the present invention still fall within the protection scope of the technical solution of the present invention.
Claims (5)
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| CN110374497A (en) * | 2019-08-29 | 2019-10-25 | 田振林 | A kind of drilling equipment and its boring method in fire damp hole |
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| EP0553732A1 (en) * | 1992-01-31 | 1993-08-04 | Baker Hughes Incorporated | Method and apparatus for relaying downhole data to the surface |
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| CN111322009A (en) | 2020-06-23 |
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