低温冷冲击饱水对煤体渗流性质的影响及增透试验研究  

The Influence of low-temperature cold shock saturated water on the permeability characteristics of coal body and experimental study on permeability enhancement

作　　者：王珂 袁浩 刘红威 戎彦龙 WANG Ke;YUAN Hao;LIU Hongwei;RONG Yanlong(Shanxi Anbiao Inspection and Certification Co.,Ltd.,Taiyuan 030000,China;School of Safety and Emergency Management Engineering,Taiyuan University of Technology,Taiyuan 030024,China)

机构地区：[1]山西安标检验认证有限公司,山西太原030000 [2]太原理工大学安全与应急管理工程学院,山西太原030024

出　　处：《煤矿安全》2024年第12期90-96,共7页Safety in Coal Mines

基　　金：国家自然科学基金资助项目(52304246);山西省基础研究计划(自由探索类)资助项目(20210302124222);山西省回国留学人员科研资助项目(2023-057)。

摘　　要：煤层气开发工作中,由于煤层的普遍渗透率较低,需采取有效的增透技术来提高煤层气抽采效率,低温致裂增透技术被广泛研究和应用。通过对煤体进行低温冷冲击饱水处理,模拟实际开采中的低温环境,以探究不同温度冷冲击饱水煤体的力学特性及渗流规律;采用负压饱水装置对试样进行饱水处理,试样完全饱水后,放入高低温试验箱,分别对不同试样进行常温、0、-20、-40℃的冲击;饱水试样冷冲击处理完成后,使用三轴渗流仪进行渗流试验和三轴压缩试验。试验结果表明:冷冲击处理饱水试样,会对试样造成损伤,煤体内部裂隙发育扩张,试样抗压强度减小,渗透率增大;随着冷冲击温度的降低,试样的渗透率逐渐增大;-40℃冲击的试样初始渗透率最大,较常温试样增长了202.9%。In the development of coalbed methane(CBM),due to the generally low permeability of coal beds,effective permeability enhancement technology is needed to improve the extraction efficiency of CBM.Among them,low-temperature fracturing and permeability enhancement technology has been widely studied and applied.In this paper,we simulate the low-temperature environment in actual mining by applying low-temperature cold impact water saturation treatment to the coal body,in order to investigate the mechanical properties and seepage law of the coal body saturated with cold impact water at different temperature conditions.Negative pressure water-saturated device is used to saturate the specimen,after the specimen is completely saturated with water,it is put into the high and low temperature test chamber,and different specimens are impacted at room temperature,0℃,-20℃ and -40℃,respectively.After the cold shock treatment of water-saturated specimens was completed,a triaxial percolation meter was used to carry out percolation test and triaxial compression test.The test results show that:cold shock treatment of water-saturated specimens will cause damage to the specimen,the development and expansion of internal cracks in the coal body,the specimen compressive strength decreases,and the permeability increases.And with the decrease of cold impact temperature,the permeability of the specimen gradually increases.The initial permeability of the specimen impacted at -40℃ was the largest,which increased by 202.9% compared with the normal temperature specimen.

关 键 词：煤层气 冷冲击 渗透率 低温致裂 饱水试样 声发射 

分 类 号：TD712[矿业工程—矿井通风与安全]