断层封闭性对西湖凹陷平湖油气田的油气分布具有重要的控制作用,对其开展系统的研究和评价是目前勘探实践的需要.利用断层泥比率、泥岩涂抹潜力及构造应力场分析等方法对平湖油气田5条主要断层进行了封闭性综合评价.结果表明:当断层泥比率大于60％且泥岩涂抹潜力大于4时,基本达到断层侧向封闭条件.断层封闭性与构造应力相关,拉张应力期,断层开启；挤压应力期,断层封闭.平湖油气田0号断层在平湖组P4—P12砂层组沉积时期封闭性好,在平湖组P1—P3砂层组沉积时期封闭性差；在花港组沉积时期断层封闭性中等.1号断层在平湖组沉积时期封闭性较好,在花港组沉积时期封闭性差.2号断层在平湖组沉积时期封闭性较好,在花港组沉积时期封闭性好.4号断层和11号断层在平湖组、花港组沉积时期封闭性均差.%Exploration practice showed that fault-sealing controlled the hydrocarbon distribution in Pinghu oil and gas field of Xihu depression, while the corresponding research had not been carried out. According to the sand-mud docking relationship on both sides of faults and smear gouge ratio calculation, fault-sealing evaluation of the main five faults in research area were studied , and the fault-sealing history in the key hydrocarbon migration period was reconstructed by the technology of layer flatten. The research results showed that fault-sealing in Pinghu Formation was better, and in Huagang Formation was weaker, when smear gouge ratio was more than 68 percent, fault side blocking were formed. Fault-sealing ability was changed by the various tectonic evolutionary stages and had relationship with tectonic stress field; in the faulted stage, the research area was mainly in tensile stress, and the faults was open; in the depression stage, some regions was mainly in compression-torsion stress, and the faults in the area was seal such as number 1 fault and in the north of number zero fault, fault-sealing in the other regions was weak.
展开▼
