中文摘要：

为了研究超压对碎屑岩储层机械压实作用的抑制作用和预测超压背景下碎屑岩储层的孔隙度,本文根据压力平衡原理,推导了地层超压与有效埋深的关系方程,并在综合考虑超压、溶蚀和胶结作用的基础上,建立了超压背景下储层孔隙度的预测模型。结果表明,盆地中地层的密度越小,超压对碎屑岩储层机械压实的抑制效果越明显。三个不同时代、不同类型沉积盆地的孔隙度预测结果表明,应用本文建立的储层孔隙度预测模型所预测储层孔隙度的误差均低于Gluyas和Cade方程,而且孔隙度预测的误差随地层时代的变老而增大。在储层胶结物小于10%的条件下,新生代超压盆地碎屑岩储层孔隙度的预测误差小于2%,而中生代超压盆地储层孔隙度的预测误差大于5%。本文建立的超压背景下的碎屑岩储层孔隙度预测模型仅适用于时代较新超压盆地的孔隙度预测。

英文摘要：

In order to study the retardation of mechanical compaction in clastic rocks by overpressure and to predict the porosity of the clastic reservoir in overpressure formation,the relationship equation of overpressure and effective burial depth was deduced using the pressure balance principle.A new model of reservoir porosity prediction in overpressure formation was developed considering the combined effects of overpressure,dissolution and cementation.The model indicated that the smaller of the formation density,the more remarkable retardation of mechanical compaction in clastic rocks by overpressures.The porosity prediction results of three different basins indicated that the precision of our porosity prediction model is higher than that of Gluyas and Cade＇ model,and the precision of our porosity prediction increases as the age of basin decreases.When the cement content in the clastic reservoir is less than 10%,the porosity prediction error of our model is less than 2% in the Cenozoic overpressure basin,the porosity prediction error is greater than 5% in the Mesozoic overpressure basin.Therefore,our model is more accurate in the prediction of younger basin.