渤海曹妃甸6-4油田东三段储层孔隙演化定量分析

Quantitative analysis on the reservoir pore evolution of the Ed3 in CFD6-4 oilfield, Bohai sea

利用铸体薄片、扫描电镜、常规物性、X射线衍射等资料,对渤海石臼坨凸起曹妃甸6-4油田东三段储层埋藏成岩过程中的孔隙演化进行了定量分析。结果表明:东三段储层埋藏成岩后经历4个孔隙演化阶段,模型计算初始孔隙度平均为32.24%;早成岩A期压实减孔阶段,储层孔隙演化受控于早期机械压实,减少孔隙度5.79%;早成岩B期压实+早期胶结减孔阶段,压实作用减少孔隙度9.62%,早期胶结作用减少孔隙度2.33%;中成岩A期压实-溶蚀增孔阶段,溶蚀作用增加孔隙度10.80%,受压实作用影响减少孔隙度2.16%;中成岩A期压实+中晚期胶结/交代减孔阶段,压实作用减小孔隙度仅为3.80%,胶结作用减少孔隙度为3.90%。经过成岩过程中孔隙度演化模拟,最终计算样品孔隙度平均为15.47%,与气测孔隙度相对误差平均为2.52%,误差相对比较小。本文研究成果对于该区优质储层预测具有一定参考意义。

The reservoir pore evolution during the diagenesis of the Ed3in CFD6-4 oilfield of the Bohai Shijiutuo bulge has been quantitatively analyzed by virtue of thin-film casting,scanning electron microscopy,conventional physical properties and X-ray diffraction.The results show that after the burial diagenesis of the Ed3reservoir,it has undergone four pore evolution stages.The initial porosity calculated by model is 32.24%on average;the compaction-pore reduction period in the early diagenesis A stage,the reservoir pore evolution was controlled by early mechanical compaction,and the porosity was decreased by5.79%;the early diagenesis B stage compaction+early cementation-pore reduction stage,the compaction reduced porosity by 9.62%,and the early cementation reduced porosity by 2.33%;the compaction-dissolution pore enhancement stage in the middle diagenesis A stage,the dissolution increased the porosity by 10.80%,and compaction reduced porosity by 2.16%;the middle diagenesis A stage compaction+middle-late cementation/metasomatic pore reduction stage,the compaction reduced porosity by 3.80%only,and the cementation reduced porosity by3.90%.By the simulation of pore evolution during the diagenesis,the calculated final porosity of the sample is 15.47%on average,and the relative error with the measured porosity is 2.52%on average.The error is relatively small,and the research result of this paper show a certain reference significance for the prediction of high quality reservoirs in this area.