Application of Fisher discriminant method in the facies division of lake facies-Taking the third member of Shahejie Formation in Dongying Sag as an example

ABSTRACT

A large number of lacustrine mudstones were formed in the third member of Shahejie Formation in the Paleogene in the DongyingSag. It is the main source rock and lithologic reservoir development layer in Dongying area. Based on the viewpoints of the predecessors, core observation, and logging data analysis, the lithologic characteristics of the third member of Shahejie Formation (including mineral content, sedimentary structure and organic matter content) were summarized. With the logging method, the logging curves such as GR, AC and R25 were selected to establish the recognition mode. Fisher discriminant analysis was performed using SPSS software to establish a quantitative partitioning scheme. The experimental results show that the lacustrine mudstones in the third member of Shahejie Formation in Dongying Sag can be subdivided into seven types of lithofacies, each of which has different identification characteristics; the discriminant equation can be established through discriminant analysis to distinguish different types of facies. It provides a research idea for the identification and prediction of lithofacies for the well sections lacking coring data and logging data.

KEYWORDS:

• Lacustrine mudstone
• lithofacies division
• SPSS software
• Fisher discriminant method
• Shahejie formation