某复杂断块油田岩性水性双重作用下的储层电性特征及测井解释评价方法

A Study on Electrical Characteristics and Logging Evaluation Method in a Fault-block Oilfield with the Complex Lithology and Formation Water System

该油田纵向上电阻率5Ω·m的油层和电阻率200Ω·m的水层并存,油气层电阻率与水层电阻率具有较大的相交范围(5~200Ω·m),测井储层流体识别和评价困难。岩石物理、试油、测井等资料研究表明不同流体性质储层呈现如上电阻率特征的原因是储层孔隙结构和地层水性质的复杂性。孔隙结构复杂的储层具有高束缚水饱和度和相对低油气冲注的特征,从而储层导电能力增加,呈现相对低阻油气层特征。断层封堵性差异造成的天然水淹是形成该区地层水性质局部突变和形成天然水淹层相对高电阻率的测井特征的原因。针对该区孔隙结构和地层水性质的复杂局面,利用储层孔隙结构及地层水突变的测井响应特征,采取储层分类和水性分类的方法,针对不同孔隙类型和地层水性质储层采用相应的模型、参数和标准,从而客观有效的评价了该区储层流体性质。

As the resistivity of oil zone and water zone have a large scope intersection （5 ~ 200 II ？ m） , the logging reservoir fluid indentification and evaluation in the field is confronted with the difficulty. Analysis with petrophysical data, logging data, test data and so on indicated that the complicated pore structure and formation water distribution control the resistivity of different fluid reservoir. The reservoir with complicated pore structure have higher irreducible water saturation and lower oil saturation, the character enhance the conductive ability of reservoir, the oil zone in the type reservoir have relatively low resistivity. The sealing of the fault made the local mutation of formation water property and formed natural water flooded phenomenon, then the fresh water flooded zone have relatively high resistivity. So the reservoir and formation water classification based on the logging response characteristics of reservoir pore structure and formation water mutations can solve the problem of reservoir fluid reservoir evaluation.