低频含水岩石介电高值成因及改进测量方法  

Cause for dielectric highs measured on wet rocks at low frequencies and an improved measurement

作　　者：肖毅[1] 柯式镇[2] 邓宏文[1] 李玉泉[3] 李艳华[4] 

机构地区：[1]中国地质大学能源学院,北京100083 [2]中国石油大学,北京102249 [3]大港油田集团测井公司,天津300280 [4]中国石化石油勘探开发研究院,北京100083

出　　处：《地球物理学进展》2009年第2期657-662,共6页Progress in Geophysics

摘　　要：含水岩石在低频下常常呈现高达10^4以上的介电常数值，数值模拟和实测结果都表明这是由于岩石中存在着传导电流，其具有与外场同相和正交的实、虚部，这二者通过与频率成反比的关系叠加在介电常数上．提出在平行板电容器一极板与被测岩石样品间夹入不导电薄膜的办法来消除传导电流的不利影响．对标准件的测量表明该方法的最大误差在4％以内．用该方法测量淡水饱和岩石样品，结果得到合理适中的介电常数值及清晰明了的介电极化谱．除湿岩石外，该方法还适用于冰、生物肌体等固态导电介质的介电谱研究．Wetorocks exhibit relative dielectric values as high as 104 and above which are elusive to explanation. Numerical modeling and measurements show that conduction current exists in rocks. Both quadrature and in-phase components of the conduction current, via inverse proportion to frequency, superimpose on permittivity. We propose to eliminate the influence of the conduction current by inserting an insulating thin film between one polar plate of the parallel capacitor and the rock sample. The measurement on standard sample shows the method has a maximum error within 4%. Measurements on fresh-water saturated rock samples obtain reasonable and moderate permittivity values and clear polarization spectra. The method can also be used to measure dielectric spectra of other solid conductive media such as ice, organic bodies and etc.

关 键 词：介电常数 介电测量 含水岩石 传导电流 

分 类 号：P631[天文地球—地质矿产勘探]