Types of Diagenetic Facies of Tight Sandstone Reservoir and Its Quantitative Identification by Well Log Data

Abstract

According to the features of clastic mineral components, diagenesis, diagenetic mineral combination, etc., the tight sandstone reservoir of Es3x 1 in block Zhuang62-66 is classified into 5 types of diagenetic facies by the analysis of thin sections, casting thin sections, scanning electron microscopy and core description. Natural gamma (GR), true forma- tion resistivity (Rt), flushed zone formation resistivity (Rxo), compensated neutron (CNL), density (DEN), acoustic (AC) and spontaneous potential (SP) are selected on the basis of comprehensively analyzing the log response mechanism of dif- ferent diagenesis. The effective log recognition model of diagenetic facies is established on the basis of principal compo- nent analysis, five comprehensive variables F1~F5 are built, while F1 and F2 account for 91.4% of the total variance, which could replace primitive multi-dimension information. The method is verified through processing of coring wells, thus providing a geological basis for the high quality reservoir prediction of the oilfield in the future.