Hydrocarbon generation simulation of different Carboniferous source rocks in the Junggar Basin

Previous studies on the hydrocarbon generation potential of Carboniferous source rocks in the Junggar Basin mainly focused on the analysis of static geochemical parameters, but no systematic evaluation of dynamic hydrocarbon generation potential has ever been carried out, which indeed constrains the understanding of resource potential and the identification of play fairways. Rock samples were collected from various types of source rocks deposited in different environments for thermal simulation experiments, and a comparative analysis were performed on hydrocarbon generation products, yield characteristics and kinetic characteristics of hydrocarbon generation. The following results were obtained. (1) The hydrocarbon yields of the Cretaceous source rocks deposited in different sedimentary environments vary greatly. The rank of source rocks from high to low in respect of hydrocarbon yields is mudstones deposited in inter-arc basins, mudstones of lagoon facies in back-arc basins, mudstones of offshore-shallow marine facies in remnant-ocean basins, and tuffaceous mudstones. (2) The hydrocarbon yields are controlled by kerogen types of source rocks and the evolution of organic matters. The more favorable the kerogen types, the higher the hydrocarbon yields. Moreover, the stronger the impacts of volcanic activities, the lower the hydrocarbon yields. (3) The dark mudstone source rocks developed in inter and back-arc basins have relatively higher hydrocarbon yields. The Wulungu Depression and the Dishuiquan area have well-developed mudstone source rocks deposited in inter-arc basins and lagoons during the Carboniferous, thus are favorable play fairways with the Carboniferous strata as the kitchen in the Junggar Basin.