不同低温下页岩渗透特征及孔隙结构试验研究  

Experimental study on permeability characteristics and pore structure of shale at different low temperatures

作　　者：尚晓吉[1,2] 杨维好 王建国[1,2] 翟成 张志镇 SHANG Xiaoji;YANG Weihao;WANG Jianguo;ZHAI Cheng;ZHANG Zhizhen(State Key Laboratory for Geomechanics&Deep Underground Engineering,China University of Mining&Technology,Xuzhou,Jiangsu 221116,China;School of Mechanics and Civil Engineering,China University of Mining&Technology,Xuzhou,Jiangsu 221116,China;School of Safety Engineering,China University of Mining&Technology,Xuzhou,Jiangsu 221116,China)

机构地区：[1]中国矿业大学深部岩土力学与地下工程国家重点实验室,江苏徐州221116 [2]中国矿业大学力学与土木工程学院,江苏徐州221116 [3]中国矿业大学安全工程学院,江苏徐州221116

出　　处：《采矿与安全工程学报》2022年第4期808-816,共9页Journal of Mining & Safety Engineering

基　　金：国家重点研发计划项目(2020YFA0711800);中国博士后基金项目(2020M681772);江苏省科技计划青年基金项目(BK20220232)。

摘　　要：为研究低温对页岩孔隙结构损伤的影响,对页岩试样进行-196,-38,-19,-7℃条件下的不同低温处理。针对低温处理后的页岩试样进行渗透实验,得到渗透率随温度的演化规律。分别应用X射线衍射、电镜扫描及高压压汞手段,对冻结前后的岩样进行矿物成分与孔裂隙结构特征测试。试验结果表明:在温度从20℃降低至-196℃过程中,页岩渗透率呈现先增大后减小而后剧烈增大的趋势;页岩的主要成分石英、白云母、长石及绿泥石等随温度降低均发生相对含量的改变,其中长石及绿泥石的含量变化与页岩渗透率行为表现一致;-38℃前页岩内部孔隙总体积变小,而后随温度降低,中大孔逐渐发育联通,产生微裂隙的扩展。In order to study the effect of low temperature on shale pore structure damage, shale samples are treated at-196,-38,-19 and-7 ℃. The permeabilities of shale samples treated are tested and the evolution law of permeability with temperature is obtained. The test methods of X-ray diffraction(XRD), scanning electron microscope(SEM) and high-pressure mercury injection(HHG) are used to test the mineral composition, pore and fracture structure characteristics of rock samples before and after freezing. The experiment results show that when the temperature decreases from 20 ℃ to-196 ℃, shale permeability increases initially, then decreases, and increases dramatically afterwards. The relative contents of quartz, muscovite, feldspar and chlorite change with the decrease of temperature, and the variations of feldspar and chlorite content are consistent with shale permeability behavior. When the temperature is higher than-38 ℃, the total volume of pores inside the shale becomes small;with the decrease of temperature, the large pores gradually develop and connect, resulting in the expansion of micro-fractures.

关 键 词：低温 渗透率 矿物成分 孔隙结构 孔径分布 

分 类 号：TU457[建筑科学—岩土工程]