含油气泥质砂岩薄膜电位理论及其在测井中的应用  

Membrane potential of oil and gas-bearing shaly sand and its application in petrophysics

作　　者：邓少贵[1] 范宜仁[1] 

机构地区：[1]石油大学地球资源与信息学院,山东东营257061

出　　处：《石油大学学报（自然科学版）》2004年第5期34-38,共5页Journal of the University of Petroleum,China(Edition of Natural Science)

基　　金："九五"中国石油天然气集团公司重点科技攻关项目(B970105)

摘　　要：地层水电阻率是测井解释中一个极其重要的参数,目前以纯地层条件推导的用于确定地层水电阻率的自然电位理论模型不适于含油气泥质砂岩地层。根据电化学原理,并结合泥质砂岩导电特性,以实验测量为依据,系统地研究了含油气泥质砂岩薄膜电位理论,并建立了改进的自然电位模型。研究结果表明,泥质砂岩薄膜电位与岩石阳离子交换容量、含油气饱和度、接触溶液浓度差密切相关。在浓度差一定的条件下,薄膜电位随岩石阳离子交换容量、含油气饱和度的升高而增大,其中含油气饱和度的影响相当于平衡离子浓度的变化。利用自然电位测井资料确定含油气泥质砂岩地层水电阻率时,必须考虑阳离子交换容量和含油气饱和度的影响。利用改进的自然电位模型进行的实例计算结果表明,该模型可以有效地用于确定泥质砂岩地层的地层水电阻率。The resistivity of formation water is very important in logs interpretation. The existing method for determining the resistivity using spontaneous potential (SP) logs based on the clean sand theory is unsuitable for shaly sand. On the basis of the electrochemical theory and the conductivity properties of shaly sands, the membrane potential of oil and gas-bearing shaly sand was studied experimentally and theoretically. An improved SP model was provided. The membrane potential of shaly sand was influenced by the cation exchange capacity, hydrocarbon saturation and concentration difference of the contacted solutions. The membrane potentials increase with increment in the cation exchange capacity, hydrogen saturation and the difference of the salinity. The influence of hydrocarbon saturation on the membrane potential is equivalent to the changes of the cation exchange capacity of core. When determining the resistivity of formation water with SP logs, the influences of the hydrocarbon saturation and the changes of the cation exchange capacity of formation should be taken into account. The calculation example shows that the resistivity of formation water in shaly sand can be effectively determined with the improved SP model.

关 键 词：泥质砂岩 地层水电阻率 自然电位测井 含油气饱和度 阳离子交换容量 岩石 测井解释 地层条件 推导 理论模型 

分 类 号：TE321[石油与天然气工程—油气田开发工程] P631[天文地球—地质矿产勘探]