青西凹陷白垩系下沟组地应力及裂缝性储层有效性关系研究

Research of Effectiveness between Crustal Stress and Fractured Cretaceous Reservoirs in Qingxi Depression

青西凹陷白垩系下沟组因其沉积因素导致储层岩性非常复杂,给从岩性出发的储层有效性评价带来困难。研究区生产实践表明,产量高低与裂缝的发育情况息息相关。因此,结合声电成像测井,在岩石物理试验、关键井地应力及裂缝研究的基础上,明确了区域地应力与储层裂缝发育规律的关系,进而提出了利用裂缝的法向应力评价储层有效性的方法。该方法在研究区取得较好的应用效果。

In Xiagou Formation of Cretaceous System in Qingxi Depression,complex lithology was induced by depositional factors,which caused difficulty for the effective evaluation of lithologic reservoirs.The production practice shows that oil output are closely related with fracture development conditions.Therefore combined with electronic and sonic image logging,the relationship between the regional crustal stress and fracture development law is clarified based on petrophysics test,the study of crustal stress and fractures of the key wells.And then,the method using normal stress of fractures to evaluate reservoir's effectiveness is put forward.This method obtains good result in the application.