The le - an oil field is located on the southern slope of dong - ying sag . there are two sets of ek basalt in its western block . depending on the drilling , the logging and the seismic date , tha ek basalt has the characteristics of high resistancs , the low sound wave defferance and faradic conductance , the smooth curve of self potential 乐安油田位于东营洼陷南斜坡上,其西区发育了两套孔店组玄武岩,根据钻井、测井、地震资料,孔店组玄武岩具有电阻率高、声波时差值和感应电导率值低、自然电位曲线平直的特点,地震波呈板状强反射;沉积期该区有有二次火山活动,玄武岩平面分布比较稳定,喷发方式为“裂隙式喷溢” ,火山口分别位于草12和草31井附近。