Drilling method and drill pipe for rotary cutting of soft coal seams to reduce resistance and protect holes

A technology for soft coal seam and hole protection, applied in drilling equipment and methods, drill pipes, drill pipes, etc., can solve the problems of shallow drilling depth, low drilling efficiency, and large drilling resistance, and reduce rotation and propulsion. Resistance, reasonable matching, and the effect of reducing confining pressure

Active Publication Date: 2017-04-12
HENAN POLYTECHNIC UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] The purpose of the present invention is to provide a drilling method and drill pipe for rotary cutting resistance reduction protection holes in soft coal seams, so as to solve the problems of large drilling resistance, shallow drilling depth and low drilling efficiency of conventional casing drilling tools

Method used

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  • Drilling method and drill pipe for rotary cutting of soft coal seams to reduce resistance and protect holes
  • Drilling method and drill pipe for rotary cutting of soft coal seams to reduce resistance and protect holes
  • Drilling method and drill pipe for rotary cutting of soft coal seams to reduce resistance and protect holes

Examples

Experimental program
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Effect test

Embodiment 1

[0035] Embodiment 1: Used in soft coal seam rotary cutting method to reduce resistance and protect holes, and evaluate the drilling shrinkage ratio d according to the geological conditions of the coal seam c And determine the rotary cutting depth, drilling speed and air supply air volume, and use the rotary cutting resistance reducing drill pipe to drill the hole. The drill pipe rotates and continuously cuts the coal body that expands and deforms in the drilling hole, and realizes the integration of rotary cutting resistance reduction and hole protection Drilling, the method comprises the steps of:

[0036] ①. Take coal samples at the construction site, test the uniaxial compressive strength of the coal samples in the laboratory, apply the geological strength index method, evaluate the mechanical parameters of the coal body, and calculate the drilling shrinkage ratio d c , the drilling shrinkage ratio d c is the maximum displacement u of the borehole wall deformation p Ratio...

Embodiment 2

[0044] Embodiment two: if Figure 4 , Figure 5 As shown, the difference from Embodiment 1 is that the open space L between the blades 1 of the rotary-cutting protection hole becomes larger, and the slag feeding capacity of the rotary-cutting resistance-reducing protection hole drill pipe along the open space L increases, but the rotary-cutting protection hole The hole protection space formed between the blade 1 and the supporting blade 2 is reduced. Therefore, this type of rotary cutting drill pipe for reducing resistance and protecting holes is suitable for drilling shrinkage ratios of 20≤d c ≤40% coal seam drilling.

Embodiment 3

[0045] Embodiment three: as Image 6 , Figure 7 As shown, the difference from Embodiment 1 and Example 2 is that the drill pipe joints of Embodiment 1 and Example 2 adopt threaded connection 31, while the drill pipe joint of Embodiment 3 adopts plug-in connection 32, and the plug-in connection, The drill pipe can be reversed, but the installation and removal of the drill pipe is not as convenient as threaded connection.

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Abstract

The invention discloses a drilling method used for a rotary cutting and resistance reducing protection hole of a soft coal layer and a drilling rod. The drilling method used for the rotary cutting and resistance reducing protection hole of the soft coal layer applies a rotary cutting and resistance reducing protection hole drilling rod to rotationally cut and drill an expanded and deformed coal body; meanwhile, the rotary cutting a depth, the drilling speed and the air supply amount of the rotary cutting and resistance reducing protection hole drilling rod are determined according to a drilling hole retraction ratio dc; the rotary cutting and resistance reducing protection hole drilling rod comprises a rotary cutting protection hole blade, a supporting blade and a central drilling rod body. Aiming at the technical difficulties that the soft coal layer is difficult to drill, a lot of engineering practices are combined; geological conditions of the coal layer are considered to invent the drilling method used for the rotary cutting and resistance reducing protection hole of a the soft coal layer and the drilling rod according to rock mechanics related theories; in a drilling process, the drilled hole wall expanded and deformed wall body can be cut off in time by the rotary cutting protection hole blade so that the rotation and propelling resistance of the drilling rod are reduced. The design is novel and a rotary cutting and resistance reducing, and protection hole integrated drilling process system is established, so that the drilling effect of a soft coal rock stratum can be effectively improved.

Description

technical field [0001] The invention belongs to the technical fields of coal seam drilling construction under complex conditions in coal mines, soft and broken rock formation drilling engineering, and the like, and in particular relates to a drilling method and a drill rod for rotary cutting of soft coal seams to reduce resistance and protect holes. Background technique [0002] For the safe mining of coal and gas outburst mines, the Chinese government clearly requires "drainage before mining" and "drainage up to standard". With the in-depth development of coal mining, the occurrence of coal seams has the characteristics of "three highs and two lows" (high ground stress, high gas content, high gas pressure, low permeability, and low coal strength), and the complexity of coal seam conditions makes drilling more difficult. for difficulty. At present, the drilling construction of soft coal seams has problems such as shallow drilling depth, low drilling efficiency, and frequent...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): E21B7/00E21B17/00
Inventor 王永龙孙玉宁宋维宾王振锋
Owner HENAN POLYTECHNIC UNIV
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