金湖凹陷阜二段碎屑岩储层成岩演化定量分析

通过微观薄片图像分析、流体包裹体分析与储层物性实验相结合的手段,获取原始孔隙度、现今孔隙度、胶结物量、交代物量、填隙物量、溶蚀量、成岩期次、成岩温度等多种数据,并运用数据统计分析将面孔率转化为孔隙度,结合成岩作用与成岩阶段分析,定量研究了金湖凹陷阜二段碎屑岩储层的成岩演化过程。研究认为金湖凹陷阜二段碎屑岩储层成岩过程较为复杂,胶结作用强烈,早晚两期胶结共造成了平均25.2%的孔隙损失,压实作用也造成了近15%的孔隙损失,溶蚀作用则提高了15.2%的孔隙度,成岩阶段整体上进入中成岩A期,部分达到中成岩B期,而储层在进入中成岩A期时,演化方向分为两支,一支主要发育胶结作用成为差储层,另一支则经历了溶蚀、压实、晚期胶结作用后进入中成岩B期,但仍可成为低渗透的有效储层。

Quantitative analysis for diagenetic evolution of elastic reservoirs in the second member of Funing Formation in Jinhu Sag

Multiple data including original porosity, current porosity, amounts of cement, replacement, interstitial mate- rial, and corrosion, and the stage and temperature of diagenesis, etc. were calculated by means of reservoir physical proper- ties in combination with analysis of microscopic flack images and fluid inclusions. And facial porosities were converted into porosities by the statistical analytical method. According to the diagenesis and diagenetic stage, we made a quantitative study on the diagenetic evolution of the clastic reservoir in the second member of Funing Formation in Jinhu Sag. Results show that the diagenetic process of the reservoir was complex and had strong cementation. An average 25.2 percent of po- rosity loss was caused by the cementations of the early and late stages ,an approximate 15 percent of the porosity loss was caused by compaction, and a 15.2 percent of porosity was increased by dissolution. The diagenetic stage of the reservoir in- tegrally entered the stage A of middle diagenesis phase, and partly went into the stage B of middle diagenesis phase. After entering the stage A, the reservoir evolution was divided into two directions ： one branch of the reservoir was mainly devel- oped under the cementation and became poor reservoir;another branch of the reservoir was developed under the dissolu- tion, the compaction, and the late stage cementation, however, it still became favorable low- permeability reservoir.