Hydrocarbon Generation And Expulsion Appraisment For Cambrian-Ordovician Source Rocks, Tarim Basin

Cambrian-Ordovician source rocks mainly develop in the platform-basin transitional area of Tarim basin,generally have the following characteristics: low organic matter abundance and high maturity,while experienced polycyclic tectonic movement and the complex process of concentration and generation of oil and gas. That evaluating oil-gas production and period of the complex Cambrian - Ordovician source rocks directly affects the evaluation of exploration potential and the decision of favorable target selection. According to this question , this article researches that developing high-temperature pyrolysis and conventional thermal simulation,and combining with principles of chemical kinetics to establish kinetic model of hydrocarbon,and then calibrate kinetic parameters of marine source rocks. Kinetics model achieves dynamics and quantitative evaluation of hydrocarbon generation of the Cambrian - Ordovician source rocks,witch obtains from Kinetic parameters with the burial history and thermal history of the Tarim Basin obtained Cambrian - Ordovician source rocks. then guide the selection of major exploration targets. The evaluation result show that the cumulative amount of hydrocarbon generation of cambrian-ordovician hydrocarbon source rocks is 9.19×105 billion cubic meters(Taking into account the two different genetic types of natural gas,one is kerogen cracking gas and another comes from oil, in which kerogen is 3295 billion cubic meters gas, gas cracking from oil reachs 5890 billion cubic meters), the amount of net oil is 174 billion tons. Hydrocarbon generation of kerogen occurred in the Caledonian. Crude oil cracking gas mainly occurred in the Hercynian. In the Mesozoic hydrocarbon generation is almost at a standstill,while in the Cenozoic,there are a large number of hydrocarbon generation.Through the research of hydrocarbon generation intensity of cambrian-ordovician hydrocarbon source and tectonic framework of tarim basin suggesting that the northern and central of tarim are the favorable area, while the eastern and southwestern of tarim also have large exploration potential.