Hydrocarbon migration law and model of Chang 9 reservoir in Jiyuan area,Ordos Basin

The research means and methods of reservoir geochemistry,reservoir geology and sedimentology are applied to discuss the hydrocarbon sources,migration mechanism,dynamics and accumulation pattern of Chang 9 reservoir in Jiyuan area.The result shows that the crude oil of Chang 9 reservoir comes primarily from the high-quality hydrocarbon source rocks of Chang 7 reservoir,of which the hydrocarbon migrated downward and accumulated in Chang 9 reservoir.The main dynamic of Chang 7 hydrocarbon migrating to Chang 9 reservoir is mainly from the abnormal high pressure of Chang 7 hydrocarbon source rock hydrocarbon pressurization and excess pressure difference between Chang 7 and Chang 9 reservoir.The vertical superposition and lateral connecting sand bodies and the fractures formed in the regional tectonic activity are the favorable migration path for connecting Chang 7 high-quality hydrocarbon source rocks with Chang 9 reservoir.