Optimization of evaluation index of Paleozoic high mature marine source rock in the Lower Yangze region

摘要

With organic petrology and organic geochemistry as the method, based on the analysis of the Palaeozoic hydrocarbon source rock samples from two shallow drillings in the Lower Yangtze and well CSDP-2 in the south Yellow Sea, the organic matter abundance, type and maturity test of marine Paleozoic hydrocarbon source rocks in the Lower Yangtze area are determined to judge the validity of the hydrocarbon source rock evaluation parameters and to finally establish an assessment indicator system suitable for the high thermal evolution and matured hydrocarbon source rock area.Comprehensive analysis suggests that due to failure of the conventional source rock evaluation indexes(such as chloroform bitumen "A", pyrolysis hydrocarbon generation potential and hydrogen index), the content of organic carbon, organic micro-components and kerogen carbon isotopic composition, "bitumen reflectance" and double adamantine can be respectively used as effective indicator index of organic matter abundance, type and maturity of Paleozoic marine source rock in the Lower Yangtze region.The research results can provide important reference and guiding for the evaluation of Paleozoic highly mature hydrocarbon source rocks and the selection of index parameters in the South Yellow Sea Basin known as the marine extension of the Lower Yangtze area.