福山凹陷低阻油层成因分析及流体识别方法OA北大核心CSTPCD

Low-resistivity reservoirs have been extensively developed in Weizhou Formation of Fushan Oilfield.The unclear understanding of the mechanisms behind the formation of low-resistivity reservoirs and the accurate identification of reservoir fluids pose significant challenges to the efficient exploration and development of Weizhou Formation.In this study,the Hua-chang,Bailian and Yong̍an areas are selected as research targets.We comprehensively analyze data from rock physics exper-iments,formation water,well logging,and oil testing to investigatefive factors:formation water salinity,light cement slurry intrusion,irreducible water saturation,additional conductivity of clay,and oil saturation.By identifying the main controlling factors of low resistance in different areas,we deeply analyze the petrophysical and logging response characteristics of differ-ent genetic mechanisms and construct fluid-sensitive logging evaluation parameters such as comprehensive reservoir index,in-vasion factor,and resistance increase rate.Combining logging interpretation and production testing,we establish corresponding fluid identification charts and apply them to 58 test horizons in 27 wells in Weizhou Formation.The results demonstrate that the coincidence rate of fluid identification increases from 76%to 84%,effectively enhancing the accuracy of fluid identifica-tion in the low-resistance reservoirs of Weizhou Formation.