自然伽马能谱测井在延安地区黏土矿物分析中的应用

Application of Natural Gamma Spectrometric Logging for Clay Mineral Analysisin Yan’an Area

为了解延安地区储集层的岩性黏土矿物的种类和含量,进一步研究储集层的特征,为油田开发提供一些基本的参数。针对这些问题利用自然伽马能谱测井资料,对延安地区油田储层主要是黏土矿物进行了一些研究。通过对黏土矿物数据进行深度归位处理,然后在前人的研究基础上,使用了改进的黏土矿物识别图版,用了多元回归的方法计算出黏土矿物的含量,分析了黏土矿物含量和U、Th、K含量的相关性,建立了计算黏土矿物含量的多元线性回归方程,获得了黏土矿物含量沿井轴的纵向变化特征。通过研究区的实际资料证明了该方法的可行性,为研究区提供了黏土矿物含量的计算方法。自然伽马能谱测井可以提供黏土矿物中放射性元素铀钍钾的含量,为预测地层中黏土矿物的含量提供了一种简便的方法,研究黏土矿物的种类及含量对石油天然气的勘探开发以及生产具有重要意义。

To understand the types and contents of clay minerals in an oilfield reservoir and to provide basic parameters for the oilfield development, the natural gamma spectrum logging data of the main reservoir in Yan’an area were used. The logging data were processed in depth, the mineral types were determined by the improved clay mineral identification chart, the clay mineral content and its correlation with the content of uranium, thorium, and potassium were calculated by multiple regression, and the multiple linear regression equations for calculating the clay mineral content was established, and the vertical variation characteristics of the clay mineral content along well shaft were obtained. The feasibility of the method was verified by the actual data, and the calculation method of clay mineral content was provided for the study area. Therefore, the natural gamma ray spectrometry logging can reflect the content of uranium, thorium, and potassium in clay minerals, and provide a basis for predicting the content of clay minerals in the formation, which shall be of great significance for the exploration and development of oil and gas as well as the production.