Logging evaluation of total organic carbon and analysis of influencing factors in source rock of Zhu III sub-basin, Pearl river mouth basin, China.

Total organic carbon (TOC) content of source rocks is usually determined by geochemical analysis of samples, but this process takes a long time and costs a lot. Using high-resolution and continuous logging information to evaluate the TOC content can solve the above problems. Previous studies have shown that there are certain differences in the response of logging curves such as spontaneous potential (SP), acoustic interval transit time (AC), natural gamma ray (GR), resistivity (Rt) and density (DEN) to TOC. Based on the response characteristics, this article uses the logging data of nine wells in Wenchang A and Wenchang B depressions to predict TOC by multiple regression method, and proves its accuracy by comparing with the density logging method and ΔlogR method. In addition, the influencing factors of logging evaluation are discussed: ① Type difference of parent rock affects the structural evolution and reservoir conditions of upper strata; ② Different clay mineral compositions lead to the difference in the distribution of argillaceous types and content, thus affecting the logging data. Therefore, clarifying the factors affecting logging evaluation and establishing effective prediction models in different blocks have important guiding significance for oil and gas exploration and development in the Zhu III sub-basin. [ABSTRACT FROM AUTHOR]