海拉尔盆地断层封闭性研究

A Study on Fault Sealability in Hailaer Basin

海拉尔盆地同一断块群上的探井的油、气显示差异较大。分析认为断层的封闭性是影响其油、气聚集的主要因素。为此 ,从断裂带中的泥质含量、断层面所受正应力以及断块两盘的岩性对置关系等 3个方面研究了断块封闭性 ,应用地质风险概率法对断块的封闭性进行了评价。在计算断层面所受正应力时 ,仅考虑断块的垂向封闭性 ;在确定断层两盘岩性的对置关系时 ,只考虑断层的侧向封闭性 ;而在求取断裂带中的泥质含量时 ,既考虑了断块的垂向封闭性 ,又考虑了断层的侧向封闭性。通过对海拉尔盆地乌尔逊 贝尔凹陷断块封闭性的评价 ,预测出Ⅰ、Ⅱ类断块群各 5个 ,对该区下一步的油气勘探具有指导意义。

Many wells have oil/gas shows in structure traps,Halaer Basin, but they don't reach commercial oil/gas flow.The analysis result is that the sealability is main factor impacting oil/gas accumulation.Therefore,fault sealability is studied through muddy content in faulted belt,normal stress of fault face, and lithology face-to-face of two plates;fault sealability is evaluated using geology risk probability method. When normal stress is calculated,vertical sealability is considered only;when lithology face-to-face is determined, lateral sealability is considered only;but,when muddy content is estimated,considering not only vertical sealability but also lateral sealability.Through fault sealability is evaluated in Wuerxun-Beier Sag,Hailaer Basin,5 better faulted block groups are predicted,the result plays a guide role in the oil/gas exploration future.