牛居油田牛12断块东营组储层特征

牛居油田牛１２断块东营组储层主要为辫状河沉积．其砂砾岩体多分布于河道之中，显示出非连续的透镜状、带状和大面积分布的席状形态．辫状河砂体主要有河道砂坝和河道充填两种沉积．该区东营组储层的成岩矿物包括自生石英、碳酸盐、高岭石、伊利石、蒙脱石、伊一蒙混层和绿泥石等矿物．次生孔隙的发育主要是由于长石、颗粒骨架和自生碳酸盐的溶蚀作用而产生的．在４个油层组之间，储层性质具有明显的非均质性，它受辫状河的成岩特征和沉积微相的控制．

Reservoir Characteristics of Dongying FM in Niu 12 Block of Niujiu Oil Field

Reservoir sandstones of Dongying FM in Niu 12 Block of Niujiu Oil Field are Characterized mainly by braided river systems. The conglomeratic sandstones in the river systems are chiefly confined to channels,displaying discontinuous lenticularities.ribbons and sand sheets of wide area. Two main types of braided sandbodies include channel bars and channel fills. The diagenetic minerals of Dongying reservoirs contain authigenic quartz,kaolinite .illite,smectite,lillite-smectite and chlorite. Secondary porosity was created mainly by the dissolution of feldspar ,matrix and authigenic carbonate. Significant heterogeneity in reservoir quality exists amongthe four sections of the hydrocarbon-bearing formation. Reservoir quality is controlled by digenetic features and sedimentary microfaces of the braided systems.