Analysis of permeability variation and stress sensitivity of liquid nitrogen fracturing coal with different water contents

ZHANG Lei; TIAN Miao-miao; LU Shuo; LI Ming-xue; LI Jing-hua

doi:10.16285/j.rsm.2021.0754

English Version Journal Login

您当前的位置：

首页 >

文章列表页 >

Analysis of permeability variation and stress sensitivity of liquid nitrogen fracturing coal with different water contents

更新时间：2026-06-25

- Analysis of permeability variation and stress sensitivity of liquid nitrogen fracturing coal with different water contents
- Vol. 43, Issue S1, Pages: 107-116(2022)
- 作者机构：
  
  1. 中国矿业大学矿业工程学院,江苏,徐州,221116
  2. 中国矿业大学煤炭资源与安全开采国家重点实验室,江苏,徐州,221116
  3. 中国矿业大学材料与物理学院,江苏,徐州,221116
- 作者简介：
- 基金信息：
- DOI：10.16285/j.rsm.2021.0754
  CLC： TD315
- Online First：13 July 2022，
  
  Published：2022
- 稿件说明：
移动端阅览
ZHANG Lei, TIAN Miao-miao, LU Shuo, et al. Analysis of permeability variation and stress sensitivity of liquid nitrogen fracturing coal with different water contents[J]. 2022, 43(S1): 107-116.
DOI：

ZHANG Lei, TIAN Miao-miao, LU Shuo, et al. Analysis of permeability variation and stress sensitivity of liquid nitrogen fracturing coal with different water contents[J]. 2022, 43(S1): 107-116. DOI： 10.16285/j.rsm.2021.0754.

摘要

Atpresent

the technology of fracturing coal by liquid nitrogen is a new type ofanti-reflection technology of coal seam. Water content

coal rank andtemperature gradient all affect the anti-reflection of liquid nitrogen. Amongthem

water content has a significant effect on the anti-reflection effect ofliquid nitrogen cracking. In order to study the effect and mechanism of watercontent on liquid nitrogen cracking

four groups of coal samples with watercontents of 0%

4% and 6% were treated by liquid nitrogen leachingrespectively

permeability tester is used to test gas phase permeability ofcoal samples

and the permeability and stress sensitivity of coal samples atdifferent pressure points were discussed and analyzed. Some findings wereobtained. (i) Under the same confining pressure

the variation trend of gasphase permeability with effective stress generally accords with negativeexponential function k = ae−bs + c

and the correlation indexes are all greater than 0.95. (ii) When the effectivestress exceeds a certain critical value

the gas permeability of coal sample isaffected by Klinkenberg effect and presents an upward trend with the increaseof the effective stress. (iii) The increase of water content of coal sample cansignificantly promote the fracturing effect of liquid nitrogen. The mostobvious is that when water content increases from 2% to 4%

the increase ofpermeability before and after fracturing increases from 92.88% to 357.12%. (iv)The normalized permeability of coal samples before and after liquid nitrogenfracturing is treated

and it is found that coal moisture has both a negativeeffect of blocking seepage and a promoting effect of improving the fracturingeffect. The normalized permeability of coal samples before and after fracturingis complicated under the combined effect of moisture. (v) Under the same porepressure

the effective stress sensitivity of coal decreases gradually with theincrease of effective stress

and it can be significantly improved by liquidnitrogen fracturing.

Abstract

At present

the technology of fracturing coal by liquid nitrogen is a new type of anti-reflection technology of coal seam.Water content

coal rank and temperature gradient all affect the anti-reflection of liquid nitrogen. Among them

water content has a significant effect on the anti-reflection effect of liquid nitrogen cracking. In order to study the effect and mechanism of water content on liquid nitrogen cracking

four groups of coal samples with water contents of 0%

4% and 6% were treated by liquid nitrogen leaching respectively

permeability tester is used to test gas phase permeability of coal samples

and the permeability and stress sensitivity of coal samples at different pressure points were discussed and analyzed. Some findings were obtained.（i） Under the same confining pressure

the variation trend of gas phase permeability with effective stress generally accords with negative exponential function k = ae

-bσ

+ c

and the correlation indexes are al

l greater than 0.95.（ii） When the effective stress exceeds a certain critical value

the gas permeability of coal sample is affected by Klinkenberg effect and presents an upward trend with the increase of the effective stress.（iii） The increase of water content of coal sample can significantly promote the fracturing effect of liquid nitrogen.The most obvious is that when water content increases from 2% to 4%

the increase of permeability before and after fracturing increases from 92.88% to 357.12%.（iv） The normalized permeability of coal samples before and after liquid nitrogen fracturing is treated

and it is found that coal moisture has both a negative effect of blocking seepage and a promoting effect of improving the fracturing effect. The normalized permeability of coal samples before and after fracturing is complicated under the combined effect of moisture.（v） Under the same pore pressure

the effective stress sensitivity of coal decreases gradually with the increase of effective stress

and it can be significantly improved by liquid nitrogen fracturing.

关键词

Keywords

references

Views

下载量

CSCD

Alert me when the article has been cited

提交

Tools

Publicity Resources

Study of stress-sensitivity of low-permeability reservoir based on arrangement of particles

Variation of internal friction angle of tailings with standard penetration number under influence of water content

Experimental study of impact of loading history on permeability characteristics of broken coal with different grain size gradations

Centrifugal model test on seepage characteristics of high core rockfill dam

Hydraulic scouring resistance characteristics of geosynthetics reinforced slopes

Related Author

LEI Gang

DONG Ping-chuan

YANG Shu

WANG Bin

WU Zi-sen

MO Shao-yuan

LI Zhi-ping

PENG Zhen-bin

Related Institution

MOE Key Laboratory of Petroleum Engineering, China University of Petroleum

School of Geosciences and Info-Physics, Central South University

Changsha Design and Research Institute of Ministry of Chemical Industry

School of Civil Engineering, Central South University

State Key Laboratory for Geomechanics & Deep Underground Engineering, China University of Mining & Technology

AI问答

⁰