沾化凹陷渤南洼陷沙四段油气成藏研究

Study on hydrocarbon migration and accumulation of Member 4 of Shahejie Formation in Bonan sag,Zhanhua depression,China

在前人有关沙四段油源、油气充注期次等研究成果的基础上,通过盆地模拟技术,分析了渤南洼陷的沉降特征、古温压场的形成与演化。在油气两次充注的背景下,渤南洼陷的沙四段油气成藏经历了三次重要的成藏时期,即东营期第一次充注期、馆陶期第二次充注早期、明化镇期第二次充注晚期。其成藏过程严格受古能量场的控制,特别是明化镇期的快速增压对沙四段晚期成藏具重要影响。渤南洼陷沙四段油气遵循"压浮双力驱动、断砂网状输导、短距就近捕集、晚期复合成藏"的规律。

Bonan sag is an oil enriched subsag in Zhanhua depression, Jiyang depression. Member 4 of Shahejie Formation （Es^4） has great potential for oil and gas exploration. Based on the known research on the oil-source rock in Es^4 and phrases of hydrocarbon infilling, the paper analyzes the characteristics of subsidence, formation and evolution of the temperature pressure system. On the background of the two phrases of hydrocarbon infilling, the oil and gas in Es^4 experienced three important periods to accumulate： Dongying period, namely the first phrase of infilling; Guantao period, namely the second phrase of early infilling; Minghuazhen period, namely the second phrase of late infilling. The process of accumulation was controlled by energy system, especially the fastgrowing pressure had a crucial influence on hydrocarbon accumulation in Es^4. The process of accumulation conformed to the law： pressure-buoyancy driving, fault sand transportation, short distance migration and traping, and late accumulation from multiple sources.