储层孔隙度预测与有效天然气储层确定——以渤海湾盆地鸳鸯沟地区为例

PREDICTION OF RESERVOIR POROSITY AND DETERMINATION OF EFFECTIVE GAS RESERVOIRS: TAKING YUANYANGGOU AREA OF BOHAI BAY BASIN AS AN EXAMPLE

储层孔隙度主要受沉积相和成岩作用的影响和控制。通过对不同沉积微相成岩强度指数与储层孔隙度之间关系的分析，建立了储层孔隙度预测模型。据此预测出渤海湾盆地鸳鸯沟地区古近系沙三下亚段储层孔隙度主要介于5．0％～30．0％之间，孔隙度大于5．8％的有效天然气储层分布于鸳鸯沟地区的斜坡带。储层孔隙度预测误差小于2．5％，其填隙物含量为1．0％～48．0％，平均为16．1％。因此该模型可用于填隙物含量较高的碎屑岩储层孔隙度预测。

Reservoir porosity is mainly influenced and controlled by sedimentary facies and diagenesis. A prediction model of reservoir porosity is built based on an analysis of the relationship between the diagenetic intensity index (ID) of each sedimentary microfacies involved and reservoir porosity. Prediction results of this model show that the reservoir porosity ranges from5.0% to 30.0% in the lower part of the 3rd member of Shahejie Formation (Es3L) in the Yuanyanggou area of Bohai Bay Basin and the effective gas reservoirs with porosity over 5.8% are distributed on the slope zone of Yuanyanggou area. The error of prediction results is lower than 2.5%. The content of matrix is up to 1.0%-48.0%, averaging at 16.1%. This model is suitable for predicting the porosity of clastic rock reservoirs with relatively high matrix content.