摘要
Abstract
In recent years,new breakthroughs have been achieved in the Paleozoic exploration of Sinopec-operated blocks in the southern Ordos Basin.Although predicted natural gas reserves have been reported for the Upper Paleozoic Taiyuan Formation in the Xunyi-Yijun area under the mining rights of Henan Oilfield,the hydrocarbon-generating potential of Paleozoic source rocks remains unclear due to low exploration maturity and insufficient research efforts on source rocks.Based on drilling,well-logging,mud-logging and laboratory test data from drilled wells in the Xunyi-Yijun area,this paper evaluates the geochemical characteristics of Paleozoic source rocks in the study area,establishes logging-based prediction models for total organic carbon(TOC)content of source rocks,and further investigates the hydrocarbon-generating intensity and exploration potential of Paleozoic source rocks.The results show that the coal-measure source rocks of the Taiyuan Formation in the Xunyi-Yijun area are classified as good-quality source rocks with Type Ⅲ organic matter in the over-mature evolutionary stage.Logging parameters such as acoustic transit time(AC)and resistivity(RT)exhibit high correlation with measured TOC values.Multiple regression is adopted to establish TOC calculation models for dark mudstone,carbonaceous mudstone and coal rock respectively.Within the Taiyuan Formation,the mudstone thickness ranges from 20 m to 60 m and the coal-rock thickness varies from 3 m to 10 m,with the most well-developed coal-measure source rocks distributed in the southeastern part.The source rocks in the study area possess high hydrocarbon-generating intensity exceeding 20×108 m³/km²,which increases gradually from west to east.The hydrocarbon-generating center is located in the central and southeastern parts of the study area.Accordingly,the central-eastern area is preliminarily identified as the favorable target zone for subsequent Paleozoic natural gas exploration and development.关键词
鄂尔多斯盆地南部/古生界/煤系烃源岩/多元回归/生烃强度Key words
southern Ordos Basin/Paleozoic/coal-measure hydrocarbon source rocks/multiple regression/hydrocarbon-generating intensity分类
能源科技
