姬塬地区长9油层组油气运移规律及模式探讨

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

鄂尔多斯盆地姬塬地区长9油层组展示了较好的勘探前景,但对其成藏机制方面的研究却相对薄弱,成为制约勘探的难题。该文应用油藏地球化学、成藏地质学和沉积学等研究手段和方法,探讨了油气来源、运移、运移动力、运聚方式等问题。结果表明:姬塬地区长9油层组原油来源于上部长7油层组的优质烃源岩;长7烃源岩生烃增压产生的异常高压、长7与长9油层组过剩压力差是长7烃类向长9储层运移的主要动力;纵向叠置、横向上连片的砂体和区域性构造活动形成的裂缝为沟通长7优质烃源岩和长9油层组储层的优势运移通道。

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.