页岩失水过程中声电特性的试验研究  

Experimental Study on the Acoustic and Electrical Characteristics of Shale during Water Loss

作　　者：徐烽淋 唐巍 陈乔[3] 刘洪 王丹 梁永昌 XU Feng-lin;TANG Wei;CHEN Qiao;LIU Hong;WANG Dan;LIANG Yong-chang(Chongqing Fuling Shale Gas Environmental Protection Research and Development and Technical Service Center,Chongqing 408000,China;Sichuan Hongda Security Technology Service Co.Ltd.,Guanghan 618300,China;Chongqing Institute of Green and Intelligent Technology,Chinese Academy of Sciences,Chongqing 408000,China;Chongqing Institute of Geology and Mineral Resources,Chongqing 408000,China;Safe Production Supervision Authority of Emeishan City,Emeishan 614200,China)

机构地区：[1]重庆市涪陵页岩气环保研发与技术服务中心,重庆408000 [2]四川宏大安全技术服务有限公司,广汉618300 [3]中国科学院重庆绿色智能技术研究院,重庆408000 [4]重庆市地质矿产研究院,重庆408000 [5]峨眉山市应急管理局,峨眉山614200

出　　处：《科学技术与工程》2020年第24期9788-9795,共8页Science Technology and Engineering

基　　金：重庆市自然科学基金(cstc2019jcyj-msxm0749);国家自然科学基金(41502287);重庆市涪陵区科技计划(FLKJ,2018BBA3066,2018BBA3065)。

摘　　要：研究流体对岩石声电特性的影响,对了解开采过程中岩石物性变化具有重要意义。为此,利用岩心气驱水试验来探究页岩失水过程中的超声波速度、电阻率变化规律及其相互关系。结果表明:随着含气饱和度(S g)的增加,页岩纵波速度线性减小,下降幅度为9.1%,而横波速度线性增加,增加幅度为16.2%,横波速度对含气饱和度变化更加敏感;将完全饱和的岩石模拟为水层时,波速比随含气饱和度的增加而线性减小,在大于50%含气饱和度时,减小幅度增大,说明储层逐渐由含水层向含气层过渡;页岩的电阻率随着含气饱和度的增加呈指数函数递增,而岩石介电常数则随着含气饱和度的增加而呈指数函数减小;当S g<50%时,电阻率随含气饱和度增加了4.3倍,而当S g>50%时,电阻率增加了10倍,介电常数变化规律则相反,当S g>60%时,介电常数几乎不变,由此可判断当电阻率增加幅度增大,介电常数几乎不变时,则可认为储层已由含水层逐渐向含气层过渡;随着岩心电阻率的增加,纵波波速呈对数函数增加,而横波波速以对数函数递减。利用页岩失水过程中波速、电阻率的变化规律及其相互关系,对实际工程中进行含气储层的识别与评价具有重要意义,但在实际应用时还需结合其他相关参数才能更准确地评价储层。It is of great significance to study the influence of fluid on the acoustic and electrical properties of rock,so as to understand the change of rock physical properties during mining.For that reason,In the laboratory,the rock core gas flooding test was used to explore the ultrasonic velocity,resistivity change rule and their relationship in the process of shale water loss.The following results are got from the research.With the increase of gas saturation,the P-wave velocity of shale decreases linearly by 9.1%,while the S-wave velocity increases linearly by 16.2%.The S-wave velocity is more sensitive to the change of gas saturation.When the fully saturated rock is simulated as a water layer,the wave velocity ratio reduces linearly with the increase of gas saturation.The decreasing amplitude increases when the gas saturation is greater than 50%,which indicates that the reservoir is gradually transiting from aquifer to aquifer.The resistivity of shale increases exponentially with the increase of gas saturation,while the dielectric constant of rock decreases exponentially with the increase of gas saturation.When it is less than 50%,the resistivity increases by 4.3 times with the gas saturation.While it is more than 50%,the resistivity increases by 10 times,on the contrary,when it is more than 60%,the dielectric constant is almost unchanged,so it can be judged that when the increase of the resistivity increases and the dielectric constant is almost unchanged,the reservoir has gradually transited from the aquifer to the aquifer.With the increase of core resistivity,the longitudinal wave velocity increases as a logarithmic function,while the transverse wave velocity decreases as a logarithmic function.It is of great significance to identify and evaluate the gas bearing reservoir in practical engineering by using the law of wave velocity and resistivity changes and their interrelations in the process of shale water loss.However,in practical application,it is necessary to combine other relevant parameters to evaluate the

关 键 词：页岩失水过程 含气饱和度 波速 波速比 电阻率 介电常数 

分 类 号：P634[天文地球—地质矿产勘探]