镇泾油田不整合面确定方法

The method to define the unconformity in Zhenjing oilfield

本文基于镇泾油田常规测井资料及地层水测试资料,对研究区侏罗系延安组与三叠系延长组之间不整合面进行划分,建立了本区的不整合面结构,将不整合面之下划分为3种类型,分析了不同结构的测井响应及孔渗特征。研究结果表明,由于延安组与延长组不同沉积体引起的地层水电阻率不同,导致泥岩在电阻率测井上有明显的台阶,延安组为高阻泥岩而延长组为低阻泥岩。根据该方法最终确定的镇泾油田不整合面划分依据,为延安组有利区带预测提供了先决条件。

Based on the present conventional log information and formation water test data of Zhenjing oilfield, the unconformities between the Yah＇an Formation of the Jurassic and the Yanchang Formation of the Triassic in study area are defined, the construction of the unconformity in the area are set up, and the unconformities are divided into three types, the log response and the poroperm characteristics of the different construction are analyzed. The findings show that the formation water resistivity caused by the different sedimentation volumes of the Yan＇an Formation and Yanchang Formation resulted in the obvious step shaped mudstone resistivity curve on the log information, so the conclusion is that the Yan＇an Formation is high resistivity mudstone and the Yanchang Formation is low resistivity mudstone. The division criteria for unconformity in Zhenjing oilfield are defined by the method, and a prerequisite is presented to predict the favorable block of Yan＇an Formation.