THERMAL EVOLUTION AND HYDROCARBON GENERATION IN THE CAOHU SAG OF THE TARIM BASIN-BASED ON IES BASIN SIMULATION TECHNOLOGY

On the basis of single well burial history simulation in the Caohu Sag of the Tarim Basin, studies of thermal evolution and hydrocarbon generation histories have been carried out with the IES-PetroMod basin modeling software. Several conclusions were made. a) In the sag, R_o of the Cambrian and the Ordovician source rocks had reached 0.5% during the middle Ordovician and had begun to generate hydrocarbon. The peak stage of hydrocarbon generation was from the middle Caledonian to the early Hercynian. The Cambrian source rocks had entered the over mature stage during the early Hercynian. The Ordovician source rocks had entered the highly mature gas generation stage in the early Hercynian and had reached the over mature stage in the late Hercynian. b) In the east and the west edge of the sag, the Cambrian source rocks reached the oil generation peak in the middle Caledonian and the late Hercynian. The Ordovician source rocks reached the oil generation peak in the Hercynian and the Indosinian. c) In the Kuerle uplift, the Cambrian and the Ordovician source rocks had entered the mature and the highly mature stages in the early Hercynian. During the late Hercynian, hydrocarbon generation stopped and the early hydrocarbon was destroyed. From the late Hercynian to the Himalayan, the Kuerle structural nose continued subsiding, but the burial depth was limited and there was nearly no probability for secondary hydrocarbon generation.