依—舒地堑方正断陷成藏主控因素及有利区带

MASTER CONTROLLING FACTOR ANALYSES OF THE HYDROCARBON ACCUMULATION AND FAVORABLE BELT PREDICTION FOR FANGZHENG FAULT DEPRESSION IN YI-SHU GRABEN

依—舒地堑方正断陷是大庆油田勘探有利的接替领域。在前人油气成藏条件研究的基础上,对方正断陷成藏的主控因素进行了综合分析。研究认为:油气成藏存在3个主控因素,一是烃源岩的分布范围及成烃演化控制断陷油气分布,二是良好储集物性及泥岩盖层是成藏的关键,三是断层与生、储、盖层的空间匹配控制油气成藏;预测断陷内存在3个有利预探区带,应以寻找生油凹陷周边的断块油藏为主,凹陷两侧构造邻近生油凹槽,是下步勘探重点地带。

Fangzheng Fault Depression in Yi-Shu Graben is the important exploration replacing field of Daqing Oilfield.On the basis of the previous studies on the hydrocarbon accumulation conditions,the comprehensive analyses on the master controlling factors of the hydrocarbon accumulation are conducted.The achievements show that there are three main controlling factors in this aspect:the petroleum distribution of the depression is controlled by the hydrocarbon scope of the source rocks and hydrocarbon-generating evolution;the key on the hydrocarbon accumulation is the much better reservoir physical properties and mudstone caprock;and moreover the enrichment is dominated by the spatial matching between the faults and the source rocks and reservoirs and cap formation.Furthermore three favorable exploring belts are predicted for the fault depression,the fault-block oil reservoirs around the oil-generating sags should be focused and the oil generating grooves and lows nearby the both sides of the sag structures should be considered to be the important exploration areas in the future.