运用排替压力法定量预测断层侧向封闭能力——以济阳坳陷为例

Quantitatively forecasting on lateral sealing performance of fault by dis-placement pressure method-case of Jiyang depression

断层对油气的封闭作用主要体现在侧向封闭上,而断层岩的排替压力是评价断层侧向封闭的主要参数,泥质含量和埋深则是影响岩石排替压力的主要因素。断层岩的泥质含量或埋深越大,其排替压力越大,对油气的封堵能力越强。通过实验测试手段可以建立不同泥质含量断层岩的排替压力与埋深的关系,从而可以实现对断层岩排替压力的预测。断层岩与储层的排替压力差决定了断层封堵油柱高度的大小,压差越大封堵的油柱高度越大,两者具有较好的正相关性。因而通过两者的相关关系可以建立断层岩封堵油藏油柱高度的顶底界预测模型。实际应用结果表明,通过排替压力预测断层岩的封闭能力是可靠的。

Sealing performance of fault in the clastic rock is mainly reflected by the lateral sealing.The displacement pressure of fault rock is the major parameter evaluating lateral sealing of fault.The main factors affecting displacement pressure of rock are shale content and buried depth of reservoir.Oil sealing ability is more powerful with more shale contents,buried depth of reservoir and displacement pressure of rock.We can construct the correlation between displacement pressure of different shale content and buried depth of reservoir by lab test.Hence,forecasting on displacement pressure of fault rock can be achieved.The displacement pressure difference between fault rock and reservoir controls the oil-bearing column height sealed by fault.When the displacement pressure difference is more evident,the oil-bearing column height is higher accordingly.There is a good correlation between oil-bearing column height and displacement pressure difference.We can build the forecasting model of oil-bearing column height sealed by fault by the correlation.It is proved by the field application that,this model is rehable and correct.