Hydrothermal History and Hydrocarbon Generation History in Northeastern Sichuan Basin

Based on the hydrothermal history reconstruction and the estimation of erosion thickness,the hydrocarbon generation history is investigated for Permian and Upper Triassic source rocks in northeastern Sichuan basin.The study shows that the paleo-heat flow value was reached to the top(62～70 mW/m2) at early stage of Late Permian,and then decreased to the present value(averaging 45 mW/m2,bottom-hole heat flow).The maximum erosion thickness occurred on Mesozoic-Cenozoic unconformity averaging 2 100 m.The hydrocarbon generation stage of Permian source rocks occurred during Early Triassic,Late Triassic and Early-Middle Jurassic;while that of Upper Triassic source rocks appeared during Middle-Late Jurassic and Late Cretaceous.