标题：APPLICATION OF PRINCIPAL COMPONENT ANALYSIS METHOD IN LITHOLOGY IDENTIFICATION OF CARBONATE ROCKS: A CASE STUDY OF THE ORDOVICIAN YINGSHAN FORMATION IN THE TAZHONG AREA, TARIM BASIN, CHINA
摘要：The logging response of different types of carbonate reservoirs is not obvious. Therefore, the identification of carbonate reservoirs by conventional logging is a hot and difficult spot in current oil and gas exploration. In this paper, the principal component analysis method was used to conduct the fine lithology identification of the carbonate rocks of the Ordovician Yingshan Formation. Five key sensitive logging parameters (natural gamma, compensated neutron, density, flushed zone formation resistivity and acoustic time difference), which can reflect the lithology change of carbonate rocks, were selected as characteristic variables. Then, the eigenvalue, principal component eigenvectors and variance contribution rates of the correlation coefficient matrix was obtained. The lithology of the Yingshan Formation carbonate rocks is mainly limestone, and in- terbeded with a small amount of dolomite and calcite dolomite. It was found that the grainstone, dolomite and algal limestone can be effectively distinguished by using the principal component analysis method. Moreover, the lithology identification results are in well agreement with the thin section identification results, which indicats that the method is effective.
