混合介质低频介电增强效应的等效电容模型  

Equivalent Capacitor Model for Large Dielectric Enhancement in Composite Medium at Low Frequency

作　　者：郭晨[1] 秦鸿瑜[1] 刘策[1,2] 

机构地区：[1]长安大学信息工程学院,西安710064 [2]休斯顿大学测井实验室,美国休斯顿77004

出　　处：《西安交通大学学报》2013年第9期140-144,共5页Journal of Xi'an Jiaotong University

基　　金：国家自然科学基金资助项目(51277012);中央高校基本科研业务专项资助项目(CHD2011JC049;CHD2011ZD004)

摘　　要：针对油气开采时岩石等混合介质在低频段出现的介电增强现象影响测井数据准确性的问题,提出一种混合介质低频介电增强效应的等效电容(CMEC)模型。首先根据储油层岩石电参数特性建立层状含膜介质模型,并将其等效为集总电路形式进行介电谱分析;同时给出3层含膜介质的电势分布,由此分析膜层电导率及膜层厚度对介电增强特性的影响。分析结果表明:等效介电常数在低频段的增强是电容模型有效厚度在低频段减小引起的,而其增强幅度和薄膜参数之间存在着定量关系;由于CMEC模型计算含膜介质介电谱时引入的模型参数相对较少,运算量约为有限差分算法等数值模拟方法的10%。该模型可为油田地质结构的低频介电测量提供准确依据。A composite medium equivalent capacitor （CMEC） model is proposed to investigate the phenomenon of rock dielectric enhancement at low frequency, which usually leads to data error during well logging. An initial stratified model with membrane is constructed according to the electrical characteristic of the reservoir rock. The electrical spectra of the model are analyzed by utilizing the equivalent lumped circuit method. The effects of the membrane conductivity and thickness are also analyzed by the electrical potential distribution of 3-layered stratified model with membrane. The results indicate that a low frequency dielectric enhancement is caused by the decreasing effective length of capacitor model, and the membrane parameters drive the permittivity amplitude quantitatively. The computing task of the proposed CMEC model gets less than 10% of finite difference method due to the fewer calculating parameters. The CMEC model provides an accurate evaluation for the well logging dielectric measurement at low frequency.

关 键 词：混合介质 电容模型 介电增强 测井 介电谱 

分 类 号：TM201[一般工业技术—材料科学与工程]