辽河坳陷齐家-鸳鸯沟地区断层侧向封闭性综合评价

摘要

通过拟合控圈断层泥岩断层泥比率(SGR)值与其所封闭油柱高度数据,建立断层侧向封闭能力包络线的函数式,讨论断层侧向封闭能力定量评价方法,并对辽河坳陷齐家-鸳鸯沟地区断层侧向封闭性进行综合评价,研究断裂成藏期后活动性对其侧向封闭能力的影响.结果表明,齐家-鸳鸯沟地区控圈断裂SGR与其所能封闭的油柱高度具有指数函数关系,断裂成藏期后活动性是断裂侧向封闭能力重要影响因素,当控圈断裂成藏后期活动速率大于2 m／Ma时,将破坏已形成的断裂侧向封闭能力,断裂侧向封闭性对油气成藏控制作用表现在断裂侧向封闭能力影响着圈闭中油气的充满程度,断裂成藏期后活动性影响着圈闭中已聚集油气的保存与散失.研究区上台阶的沙二段及沙三段中上部断层侧向封闭能力最强,是下一步该地区油气勘探的有利目标.%By fitting shale gouge ration (SGR) of faults that control traps and oil column sealed by it, the envelope curve of lateral sealing ability of faults was established and the quantitative lateral seal of evaluation methods was carried out, and a comprehensive evaluation to lateral sealing ability of faults in Qijia-Yuanyanggou area, Liaohe depression was conducted. The effect of fault activity after accumulation on the lateral sealing ability of faults was studied. The results show that SGR of faults that control traps and oil column sealed by it are exponential function, and faults activity after hydrocarbon accumulation is the main factor that impacts lateral sealing ability. When activity rate of faults that control traps is more than 2m/Ma after hydrocarbon accumulation, the lateral sealing ability of faults will be ruined. Controlling of lateral sealing ability on hydrocarbon accumulation performed as lateral sealing ability effect hydrocarbon fullness in traps and faults activity after hydrocarbon accumulation impacts the conservation and dispersion of accumulated hydrocarbon. Sha-2 and upper Sha-3 member of upper bench has best lateral sealing ability, and they are the favorable target for exploration.