川中地区茅口组碳酸盐岩储层类型测井识别OACSTPCD

The Maokou Formationcarbonate reservoirs in the central Sichuan Basinexhibit well-developed dissolutionpores,vugs,and fractures,pronounced heterogeneity,and diverse types.This study aims to identify their types and establish the log-based identification criteria for various reservoir types.First,this study classified the reservoir types based on the analysis of casting thin sections,core photos,and micro-resistivity imaging logs.Moreover,it determined the conventional log response characteristics of different reservoir types.Finally,it conducted log-based identification of reservoir types using the fracture porosity(φf)-secondary porosity index(RP)cross-plotting method.The results are as follows:(1)The Maokou Formation carbonate reservoirs in the central Sichuan Basin can be-classified into four types,i.e.,fractured-vuggy,fractured-porous,porous-vuggy,and matrix porous reservoirs;(2)Fracture porosities calculated from different models are more similar in the case of more developed fractures,and dissolution pores and vugscan affect the fracture porositycalculation results to some extent;(3)The φf-RP cross-plotting method can effectively identify reservoir types.These research results provide technical support for the log-based identification of carbonate reservoir types.