Classification and Distribution of Insulating Layers in Linnan Oilfield

Based on detailed division and correlation of reservoir sandstones in Linnan oilfield, the insulating layers are systemically studied through core observation and well logging analysis.According to lithology and lithofacies of the layers, they are divided into mudstone insulating layers(typeⅠ), siltstone ones(typeⅡ)and carbonate-bearing ones(typeⅢ). Because of facies variation, typeⅠ insulating layers are subdivided intoⅠ¹ andⅠ², and typeⅡ intoⅡ¹ andⅡ².All the insulating layers have differentwell logging features, sedimentary assemblages and spatial distributions. Discontinuity of the insulating layers could make nearby sand layers connected.The connection between sandbarbodies or channel sand ones shows differentorigins and distinguishedwell loggingmodels.The spatial distribution characteristics of each insulating layer are concluded by the research of more than 110 well loggings, thus providing basic data for the prediction of residual oil and selection of exploitation methods.