不同阶煤岩基质收缩效应单因素物理模拟实验研究  

Single-factor physical simulation on matrix contraction effect of coal rocks with different ranks

作　　者：曹明亮 康永尚[2] 秦绍锋[1] 张兵[3] 邓泽 CAO Mingliang;KANG Yongshang;QIN Shaofeng;ZHANG Bing;DENG Ze(Taiyuan Branch,China United Coalbed Methane Corporation Ltd.,Taiyuan 030000,China;College of Geosciences,China University of Petroleum (Beijing),Beijing 102249,China;China United Coalbed Methane Corporation,Ltd.,Beijing 100016,China;Key Laboratory of Unconventional Oil and Gas,China National Petroleum Corporation,Langfang 065000,China)

机构地区：[1]中联煤层气有限责任公司太原分公司,山西太原030000 [2]中国石油大学(北京)地球科学学院,北京102249 [3]中联煤层气有限责任公司,北京100016 [4]中国石油天然气集团有限公司非常规油气重点实验室,河北廊坊065000

出　　处：《煤炭学报》2021年第S01期364-376,共13页Journal of China Coal Society

基　　金：国家科技重大专项资助项目(2016ZX05041-001,2016ZX05044)。

摘　　要：为分析不同煤阶煤岩在基质收缩效应单因素影响下渗透率动态变化特征,利用中国石油勘探开发研究院廊坊分院自行研发的LFLab-Ι煤岩三轴应力应变(基质收缩膨胀)测试系统,采用恒定有效应力的试验方法,对不同煤阶煤岩开展了基质收缩效应单因素物理模拟试验,分析了基质收缩效应对煤岩渗透率的改善作用。并通过控制单一变量,分析了煤阶及恒定有效应力对煤岩“解吸诱导”潜力的影响作用。试验结果表明:①在基质收缩效应影响下,白音华煤样(低煤阶)在恒定有效应力1.5~7.5 MPa条件下的4组平行试验归一化渗透率反弹1.57~3.68倍,平均2.23倍;兴县煤样(中煤阶)归一化渗透率反弹1.64~2.39倍,平均1.94倍;阳城煤样(高煤阶)归一化渗透率反弹1.92~3.60倍,平均2.45倍。②随气体平衡压力降低,低、中及高煤阶煤样渗透率均呈指数函数形式增加,基本以气体平衡压力3 MPa为临界点,之后渗透率快速增加。③在相同煤阶不同恒定有效应力条件下,低、中及高煤阶煤样随恒定有效应力增大,渗透率反弹效果变差。相同恒定有效应力不同煤阶条件下,恒定有效应力1.5及3.5 MPa时,低煤阶煤样渗透率反弹效果较好;恒定有效应力5.5及7.5 MPa条件下,渗透率反弹效果出现反转。此外,与煤阶的影响效果相比,恒定有效应力对动态渗透率反弹效果起着决定性作用。In order to analyze the dynamic change characteristics of permeability of coal rocks with different ranks under the single factor of matrix contraction effect,the LFLab-Ιtriaxial stress and strain(matrix contraction expansion)test system developed by Langfang Branch was used to carry out the single factor physical simulation of the matrix contraction effect on the coals of different ranks with constant effective stress methods,and analyze the effect of matrix contraction on coals permeability.By controlling a single variable,the effect of coal rank and constant effective stress on the potential of coal rocks“desorption induction”was analyzed.The experimental results show that①under the influence of the matrix contraction effect,the normalized permeability of the four sets of parallel experiments of Baiyinhua coal samples under the constant effective stress of 1.5-7.5 MPa rebounded by 1.57-3.68 times,with an average of 2.23 times;the normalized permeability of Xingxian coal samples rebounded by 1.64-2.39 times,with an average of 1.94 times;the normalized permeability of Yangcheng coal samples rebounded by 1.92-3.60 times,with an average of 2.45 times.②As the gas equilibrium pressure decreased,the permeability of low,medium and high coal rank coal samples increased as an exponential function,basically with the gas equilibrium pressure of 3 MPa as the critical point,and then the permeability increased rapidly.③Under the conditions of different constant effective stresses in the same coal rank,as the constant effective stress increases with the coal samples of low,medium and high ranks,the permeability rebound effect became worse.Under the same constant effective stress and different coal rank conditions,when the constant effective stress was 1.5 MPa and 3.5 MPa,the permeability rebound effect of low coal rank coal samples was better;under the constant effective stress of 5.5 MPa and 7.5 MPa,the permeability rebound effect reversed.In addition,compared with the effect of coal rank,the constant effective st

关 键 词：煤岩 基质收缩 物理模拟试验 渗透率 煤阶 恒定有效应力 

分 类 号：P618.11[天文地球—矿床学]