汤原断陷次级凹陷充填序列及石油地质意义

FILL SEQUENCE AND ITS PETROLEUM GEOLOGY SIGNIFICANCE IN SECONDARY SAG IN TANGYUAN FAULTDEPRESSION,

含油气盆地的油气勘探前景首先取决于次级凹陷的生烃能力，这与凹陷的性质及充填序列有密切的关系。汤原断陷发育八个次级凹陷，由于基底性质及基底控制的断裂活动性的差异，导致了多种类型的沉积和地层充填特征。通过分析汤原断陷各次级凹陷形成演化规律和地层充填序列，总结出了欠补尝型、补尝型和补尝－欠补尝过渡型三种类型的次级凹陷和地层充填模式，并通过对每一种凹陷的烃源岩发育情况及生储盖组合特征进行分析，预测了各种类型凹陷的油气勘探前景。

Hydrocarbon generation potential of source sag controls oil/gas prospecting potential in a petroliferous basin. There was very close relation between feature of sag and fill sequence. Eight secondary sags were developed in Tangyuan depression , among which the difference between basement feature and its controlling on fault movement resulted in different types of sedimentation and fill characteristics. Based on analyses of formation and evolution regularity and formation fill sequence of each secondary sag in Tangyuan depression, this paper summerized three models for secondary sag and fill sequence. On the basis of analyses of development of source rock and sourcereservoircap assemblage characteristics, oil/gas prospective potentials of different types of sag were predicted.