不同沉积韵律控制的厚层砂体水淹级别精细划分

Fine division of water flooded levels in thick sand bodies controlled by sedimentary rhythm

提出沉积韵律控制下的厚层砂体水淹级别精细划分方法.该方法以稳定泥岩隔层为划分标志,将测井曲线划分为与沉积韵律一一对应的解释单元.根据深(浅)电阻率曲线与密度测井曲线,以厚层砂体电阻率曲线的平均斜率及密度曲线的相对重心为判别参数,利用计算机自动判别每一个解释单元中所包含的原始沉积韵律类型.以每单一韵律中部为对比标准层,将韵律其他部位小层的电性、物性、时频特征参数与之比较,结合小层与标准层相对位置关系,自动判定各小层水淹级别.11口密闭取心井处理结果表明:该方法可以有效给出不同韵律内部各小层的水淹级别,与岩心分析结果相比,总符合率达到78%以上.

Currently,the water interpretation is carried out only in isolated layer,which ignores the intrinsic relevance of every layers in the sedimentary rhythm.Therefore,a method of water flooded levels finely divided in thick sand bodies controlled by sedimentary rhythm is represented.The stable mudstone barrier bed is adopted as the separates symbol for different interpretation unit that is identified from well logging curve so that only one sedimentary rhythm is contained in each interpretation unit.The Average slope of resistivity curve and relative center of gravity of density curve are adopted as discrimination parameter for identifying the original sedimentary rhythm by computer in each interpretation unit.Taking the middle of each rhythm as the standard layer with which the other layers in this rhythm are compared with electrical,petro-physical and time-frequency properties,the water flooded level of these layers are automatically discriminated to combining the relative location from the standard layer.The processing result of eleven sealed core wells show that this method can divide accurately the water flooded levels of layers in different rhythm,so the interpretation coincidental rate is up to 78% with the result of core analysis.