歧北凹陷沙二段超压背景下的成岩场分析与储层孔隙度预测

Diagenetic Field Analysis and Porosity Prediction of the Shaer Member(Es_2)in Overpressure Setting in the Qibei Depression

根据数学场论的原理,成岩场可定义为成岩强度在空间各点某一时间的成岩强度之总体,成岩强度的大小可用成岩指数ID表示。在成岩场分析、沉积相参数定量化研究、压力与储层孔隙度关系讨论的基础上,该文建立了渤海湾盆地歧北凹陷储层孔隙度预测的多元非线性高次模型:孔隙度=F(分选系数So,成岩指数ID,地层压力P)。歧北凹陷沙河街组二段滩坝砂体孔隙度的预测表明,对于胶结物含量>10%的砂体,孔隙度预测误差可<2%;歧北凹陷沙二段东部的沿岸砂坝预测孔隙度为15%～20%,是储层发育的有利地区。

The diagenetic field was defined as the whole of diagenetic intensity in the space at a certain moment according to the basic principle of field theory, which could be described by diagenetic intensity ID. A new multivariate non-leaner model, porosity = F （Trask So, diagenetic intensity ID, pressure P） , was set up on the basis of diagenetic field analysis, sedimentary parameters quantitative study, pressure and porosity correlation investigation. As the porosity prediction of beach bar sandstones of Shaer Member（ Es2 ） in the Qibei depression shows the predicted error of porosity for the sandstones with the cement of more than 10% is less than 2%, and the predicted porosity of sand bodies in the eastern Qibei depression is 15%-20% , which are the favorable reservoir area developed in the depression.