惠民凹陷临南地区断层活动特征及控油作用

断层生长指数不仅与断层活动速率有关，而且还与沉积速率有关，在有严重剥蚀的情况下该指数被严重歪曲。断层活动速率在数值上等于某时期内断层落差与相应时间的比值。同时利用断层生长指数与断层活动速率两种研究手段，对惠民凹陷临南地区的断层活动强度进行研究，将结果与各地层单元的沉积速率进行比较，发现各地层单元的生长指数不可比，而断层活动速率的研究结果揭示了断层活动的幕式性，与火山岩分布、构造沉降曲线的变化相吻合。总体来说,沙三段、东营组沉积期为临南洼陷断裂强烈活动期，东营组沉积期断层活动强度大于沙一段沉积期。钱官屯、曲堤地区的二级断层在东营组沉积末期的活动强度大、封闭性差，结合原油产层的分布，推测两地区油气成藏在馆陶组沉积以后。明化镇组沉积期局部断层的活动强度加大，油气有较明显的纵向运移。断层生长指数在实践中的应用有待商榷。图1表1参3

Fault activity features and its control over oil of Linnan area in Huimin depression

The growth index of a fault is related not only to its activity rate but also to the deposition rate, especially in seriously truncated area, the growth index is serious distorted. But this situation has been neglected for a long time. Based on growth index and fault activity rate, the activity intensity of Linnan fault is studied, and it is so considered that the conclusion of latter is right. The speed of activity of a fault can be directly attained from the duration of sedimentation and reflects quantitatively the activity intensity of the fault, thus the terminology of the growth index of fault is practically meaningless. Fault activity was strong during Dongying time, and the buried depth of stratum is shallow, so fault sealing is worse, hydrocarbons migrated to Qianguantun and Qudi areas. This is important to hydrocarbon accumulation. Fault activity intensity was big during Minghuazhen time, which determined the vertical hydrocarbon distribution.