CN-121976772-A - Flexible supporting device and method for gas extraction drilling hole collapse prevention

CN121976772ACN 121976772 ACN121976772 ACN 121976772ACN-121976772-A

Abstract

The invention discloses a flexible support device and a support method for a collapse-preventing hole of a gas extraction drill hole, belongs to the technical field of coal mine gas control and drill hole support, and solves the core problems that the existing gas extraction drill hole is easy to collapse, the support technology cannot achieve both support stability and gas extraction through-flow property, and deep hole accurate support difficulty is high. The device comprises a deep hole grouting drill rod, a flexible grid grouting supporting bag and a grouting material bag, wherein the flexible grid grouting supporting bag and the grouting material bag are in pre-butt joint, the supporting bag is of a double-cavity integrated structure with an air-permeable grid, the grouting material bag is of a three-cavity diaphragm pre-packaging structure, and the drill rod is integrated with an automatic control pushing and grouting power unit. The method adopts deep-to-shallow segmented fixed-point support to realize automatic closed-loop operation of pushing, mixed grouting and constant-pressure disconnection of support members. The invention can effectively inhibit the hole collapse of the drill hole, gives consideration to the supporting effect and the gas extraction efficiency, adapts to deep complex geological conditions, and improves the safety and the operation efficiency of mine gas control.

Inventors

CHENG CHENG
GONG XUANPING
CHENG XIAOYU
MA XINGYING
LEI HUI
CHEN LONG
SUN LINGCHAO
YANG PENG

Assignees

中煤能源研究院有限责任公司
中煤(鄂尔多斯市)能源科技有限责任公司

Dates

Publication Date: 20260505
Application Date: 20260327

Claims (10)

1. The gas extraction drilling collapse-preventing flexible support device is characterized by comprising a deep hole grouting drill rod (3), wherein a flexible grid grouting support bag (1) and a grouting material bag (2) are arranged in the deep hole grouting drill rod (3), an inlet of the flexible grid grouting support bag (1) is detachably abutted with an outlet of the grouting material bag (2), and the deep hole grouting drill rod (3) is used for conveying the flexible grid grouting support bag (1) and the grouting material bag (2) to a drilling target support position and completing grouting support operation.
2. The flexible support device for preventing hole collapse of gas extraction drilling holes according to claim 1 is characterized in that the flexible grid injection supporting bag (1) is made of flame-retardant antistatic polymer elastic materials for underground coal mines, the body part of the flexible grid injection supporting bag (1) is a bottom layer (1-6), an intermediate layer (1-5) and a top layer (1-4) which are sequentially stacked, the bottom layer (1-6) and the intermediate layer (1-5) are enclosed to form a first cavity (1-8), the intermediate layer (1-5) and the top layer (1-4) are enclosed to form a second cavity (1-7), and the bottom layer (1-6), the intermediate layer (1-5) and the top layer (1-4) are made of the same materials and are integrally formed through a one-time turnover molding process.
3. The flexible support device for preventing hole collapse of gas extraction drilling holes according to claim 2 is characterized in that a body of the flexible grid injection supporting bag (1) is of a grid structure, the flexible grid injection supporting bag (1) is provided with a plurality of ventilation grids (1-2) through which coal seam gas can pass, the head end of the flexible grid injection supporting bag (1) is provided with an inlet communicated with a first cavity (1-8), the first cavity (1-8) is used for injecting curable grouting materials to expand and support a hole wall, and the second cavity (1-7) is internally filled with heat insulation and shock absorption materials.
4. The flexible support device for preventing the gas extraction drilling holes from collapsing according to claim 3 is characterized in that a quick connection device (1-1) is fixedly arranged at the inlet of the flexible grid injection supporting bag (1), a one-way valve (1-3) is connected in series with the rear end of the quick connection device (1-1), and the conduction direction of the one-way valve (1-3) is from a grouting material bag (2) to the inside of a first cavity (1-8) and is used for blocking reverse backflow of slurry in the grouting process.
5. The flexible support device for preventing hole collapse of gas extraction drilling according to claim 4, wherein the grouting material bag (2) is an integrated liquid packaging system, the inside of the grouting material bag (2) is divided into a first chamber (2-1), a second chamber (2-2) and a third chamber (2-3) which are independent of each other through a breakable sealing membrane, the first chamber (2-1) and the second chamber (2-2) are divided through a first breakable sealing membrane (2-4), the second chamber (2-2) and the third chamber (2-3) are divided through a second breakable sealing membrane (2-5), the first chamber (2-1) stores a curing time adjusting catalyst, the second chamber (2-2) stores liquid resin, and the third chamber (2-3) is a mixing chamber communicated with an outlet.
6. The flexible support device for preventing hole collapse of gas extraction drilling according to claim 5, wherein an outlet quick connector (2-6) is fixedly arranged at the outlet of the grouting material bag (2), the outlet quick connector (2-6) is in fit and sealing connection with a quick connector (1-1) of the flexible grid injection supporting bag (1), a blasting valve (2-7) is further arranged at the outlet of the grouting material bag (2), and the set blasting pressure of the blasting valve (2-7) is matched with the rated filling pressure of the flexible grid injection supporting bag (1).
7. The flexible support device for preventing hole collapse of gas extraction drilling according to claim 6, wherein the grouting material bag (2) is of a cylindrical packaging structure, a movable bottom plug (2-8) capable of axially moving is arranged at the bottom of one end of the grouting material bag (2) opposite to the outlet, and the movable bottom plug (2-8) is used for pushing materials inside the grouting material bag (2) to flow towards the outlet when being axially extruded.
8. The flexible support device for preventing hole collapse of gas extraction drilling holes according to claim 7, wherein a flexible grid injection supporting bag storage unit (3-1), a grouting material bag storage unit (3-2), a microprocessor (3-3), a communication unit (3-4), a power pushing unit (3-5) and a power supply unit (3-6) are integrated in the rod body of the deep hole grouting drilling rod (3); the power pushing unit (3-5) comprises a central rotating rod (3-7) and a grouting material bag extrusion disc (3-8) which are coaxially arranged along the axial direction of the deep hole grouting drill rod (3), wherein the rear end of the central rotating rod (3-7) is in transmission connection with a driving module of the power pushing unit (3-5), and the front end of the central rotating rod (3-7) faces to a discharge hole of the deep hole grouting drill rod (3); The flexible grating grouting support bag storage unit (3-1) is used for pre-installing a flexible grating grouting support bag (1) to be placed, the grouting material bag storage unit (3-2) is used for pre-installing a grouting material bag (2) which is completed in a butt joint mode, the grouting material bag storage unit (3-2) is matched with the central rotary rod (3-7) through a transmission structure and axially translates along the deep hole grouting drill rod (3), the central rotary rod (3-7) is coaxially arranged in hollow structures in the middle of the grouting material bag storage unit (3-2) and the grouting material bag (2) in a penetrating mode, the grouting material bag extrusion disc (3-8) is sleeved on a rod body of the central rotary rod (3-7) through an internal thread structure in a matched mode, and is located at the rear end of the grouting material bag storage unit (3-2) and axially opposite to a movable bottom plug (2-8) of the grouting material bag (2); The communication unit (3-4) is used for receiving external control signals and transmitting the external control signals to the microprocessor (3-3), the microprocessor (3-3) transmits execution instructions to the power pushing unit (3-5) after processing the signals, and the power supply unit (3-6) supplies power for the microprocessor (3-3), the communication unit (3-4) and the power pushing unit (3-5).
9. A gas extraction drilling hole collapse-preventing flexible support method is characterized by comprising the following steps of 1, monitoring and recording the state in a hole during drilling construction, identifying a collapse-prone hole section and numbering from deep to shallow, 2, filling a butted flexible grid grouting support bag (1) and a grouting material bag (2) into a deep hole grouting drill rod (3) after drilling is completed, sending the deep collapse-prone hole area, 3, pushing the flexible grid grouting support bag (1) to a preset position and extruding grouting, enabling the flexible grid grouting support bag (1) to expand and fit a hole wall, 4, automatically breaking connection after filling, solidifying the grouting to form a support, exiting the deep hole grouting drill rod (3), and 5, repeating the operation from deep to shallow to complete the full hole support.
10. The gas drainage borehole collapse prevention flexible support method according to claim 9, wherein the method comprises the following steps: In the deep hole drilling construction process, real-time monitoring and recording are carried out on drilling construction parameters and in-hole states, key sections of holes which are easy to collapse in the drill holes are dynamically analyzed and determined, and all the easy-to-collapse hole areas are numbered in sequence from deep to shallow; The method comprises the steps of (2) after drilling construction is completed, withdrawing a drill rod in a hole, sealing and butting a quick connection device (1-1) of a flexible grid injection supporting bag (1) with an outlet quick connection device (2-6) of a grouting material bag (2), correspondingly loading the quick connection device into a deep hole grouting drill rod (3), removing an original drilling bit, replacing the original drilling bit with the deep hole grouting drill rod (3), and conveying the original drilling bit into a first hole area with the deepest serial number through a drilling machine; Slowly withdrawing a deep hole grouting drill rod (3) in a collapse hole area, simultaneously transmitting control signals to the deep hole grouting drill rod (3) through a drilling machine and a cable drill rod, driving an internal power pushing unit (3-5) to push a flexible grid injection supporting bag (1) to a preset position in a drill hole, then extruding a movable bottom plug (2-8) of a grouting material bag (2) to enable a first breakable airtight membrane (2-4) and a second breakable airtight membrane (2-5) in the grouting material bag (2) to be broken in sequence, and continuously injecting mixed slurry into the flexible grid injection supporting bag (1) after the catalyst and liquid resin are fully mixed, so that the flexible grid injection supporting bag (1) is expanded gradually and forms effective support on the hole wall; Step 4, after the slurry in the flexible grid grouting support bag (1) is filled, the explosion valve (2-7) at the outlet of the grouting material bag (2) is pressed and ruptured to automatically separate the flexible grid grouting support bag (1) from the grouting material bag (2), and then the liquid resin in the flexible grid grouting support bag (1) is quickly solidified to form stable support for a drilled hole and withdraw from the deep hole grouting drill rod (3); And 5, repeating the operations from the step 2 to the step 4, and sequentially carrying out flexible support on all the easy-collapse hole areas in the drilled hole according to the sequence from deep to shallow until the whole section flexible reinforcement operation of the whole drilled hole is completed.

Description

Flexible supporting device and method for gas extraction drilling hole collapse prevention Technical Field The invention belongs to the technical field of coal mine gas control and drilling support, and particularly relates to a gas extraction drilling collapse-preventing flexible support device and a gas extraction drilling collapse-preventing flexible support method. Background The mine gas extraction is a core technical means for coal mine gas disaster management, and is a key for guaranteeing mine extraction safety and realizing gas resource utilization. The deep coal seam generally presents the characteristics of high ground stress, strong mining disturbance and low air permeability, so that the large-aperture gas extraction drilling and directional long drilling become main technical schemes for the gas control of the deep coal seam for guaranteeing the gas extraction effect, and the structural integrity and long-term stability of the wall of the drilling hole are core factors for determining the gas extraction efficiency, the extraction service period and the control cost. In the gas extraction operation process, the gas extraction drill hole is extremely easy to deform and collapse due to the superposition influence of the stability of the coal rock stratum, the geological structure is complex, the ground stress and the mining disturbance, especially, the collapse risk of the weak coal rock stratum in the hole is further increased along with the increase of the hole diameter of the drill hole, the collapse hole can directly cause the blockage of a gas extraction channel, the effective section of extraction is reduced, the gas extraction effect cannot meet the design requirement, even the drill hole is scrapped in serious cases, the gas control cost is greatly increased, and great hidden danger is brought to the safety production of a mine. At present, aiming at gas extraction drilling collapse hole treatment, a rigid sleeve supporting technology is mainly adopted, a hole wall is supported by lowering rigid members such as a metal sleeve and a rigid PVC sleeve in a drilling hole, and the technical defect that the hole wall collapses can be inhibited to a certain extent but cannot be avoided exists in the scheme: the rigid sleeve is in hard contact with the surrounding rock of the coal rock, so that creep deformation of the deep coal rock and displacement of the surrounding rock under mining disturbance cannot be adapted, extrusion deformation and damage failure are easy to occur under the action of ground stress, and long-term stable support cannot be realized; meanwhile, the rigid sleeve can block the drilling section and the coal wall gas seepage passage in a large area, so that the effective section and the extraction efficiency of gas extraction are greatly reduced, and the supporting effect and the extraction requirement cannot be considered. In order to solve the problem of the through-flow of the rigid support, the technology of the bag grouting support is adopted in the industry step by step, and the bag is put down into a drilling hole and solidified slurry is injected, so that the bag is expanded to be attached to the hole wall to form the support, but the existing bag support scheme still has a plurality of technical bottlenecks, namely, the existing bag is of a single-cavity closed structure, free seepage of gas cannot be realized, the industrial contradiction that the support effectiveness and the gas through-flow cannot be considered is not fundamentally solved, and meanwhile, the problem that the existing bag grouting is easy to cause support failure due to insufficient slurry injection or over-grouting to block the drilling hole is solved. In conclusion, the existing gas extraction drilling hole collapse prevention support technology cannot simultaneously give consideration to support effectiveness, gas through-flow property and operation safety, is difficult to meet the engineering requirements of long-term stable support of the gas extraction drilling hole under deep complex geological conditions, and severely restricts the improvement of mine gas control efficiency and safety production level. Disclosure of Invention The first aim of the invention is to provide a flexible support device for preventing the collapse of a gas extraction drill hole, which solves the technical problems that the gas extraction drill hole is easy to collapse, and the existing support technology cannot achieve both the stability of the drill hole support and the gas extraction fluidity. The second aim of the invention is to provide the anti-collapse flexible support method for the gas extraction drilling hole, which solves the technical problem that the accurate, efficient and sectionally continuous flexible support cannot be realized in the deep easy-collapse hole area of the gas extraction drilling hole. The first technical scheme adopted by the invention is that the anti-collapse flexible support device