鄂尔多斯盆地三叠系与侏罗系不整合面测井识别方法讨论

发布时间：2018-05-31 08:59

本文选题：不整合面 + 测井资料　；参考：《西北大学学报(自然科学版)》2017年04期

【摘要】：利用区域地质背景和测井资料,用测井方法对鄂尔多斯盆地三叠系与侏罗系之间不整合面进行识别,为准确划分鄂尔多斯盆地中生代地层提供依据。研究后认为,不整合面上下地层的接触关系分为5种类型,不同类型的特征及识别方法受延长组顶部地层的剥蚀程度和前侏罗纪古地貌特征共同控制。测井方法识别不整合面最主要的依据有两个:一是河道充填砂岩形成的箱型测井曲线的底界,主要发育在甘陕古河谷;二是由于不整合面下发育黏土风化壳而使不整合面上具有电阻率值最小的特征,主要发育在古地貌的斜坡带。此外,不整合面的识别还需参考不整合面上下地层的岩性、厚度、标志层特征,同时结合邻井对比和等厚原则,才可有效准确地识别不整合面,并对不整合面上下地层的接触关系进行准确的划分。
[Abstract]:The unconformities between Triassic and Jurassic in Ordos Basin are identified by using the regional geological background and logging data, which provides a basis for the accurate division of Mesozoic strata in Ordos Basin. It is considered that the contact relationship between the upper and lower strata of the unconformities is divided into five types. The different types of features and identification methods are jointly controlled by the denudation degree of the top strata of the Yanchang formation and the paleogeomorphological features of the pre-Jurassic period. There are two main bases for identifying unconformities by logging method: one is the bottom boundary of box logging curve formed by channel filling sandstone, mainly developed in the ancient Gan-Shan valley; The other is that the unconformities are characterized by minimum resistivity due to the development of clay weathering crust under the unconformities, mainly in the slope zone of paleogeomorphology. In addition, the identification of unconformity surface also needs to refer to the lithology, thickness and marker layer characteristics of the upper and lower strata of the unconformity surface, and combine the correlation of adjacent wells and the principle of equal thickness to identify the unconformity surface effectively and accurately. The contact relationship between the upper and lower strata of the unconformities is accurately divided.
【作者单位】：西北大学地质学系;中石油长庆油田分公司勘探开发研究院;
【基金】：国家自然科学基金资助项目(41390451)
【分类号】：P618.13;P631.81

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