致密砂岩储层成岩压实作用定量评价及主控因素——以珠江口盆地文昌区珠海组三段为例

Quantitative Evaluation and Main Controlling Factors of Diagenesis and Compaction of Tight Sandstone Reservoir——a Case Study of the Third Member of Zhuhai Formation in Wenchang District of Pearl River Mouth Basin

为定量评价致密砂岩储层成岩压实作用,以珠江口盆地文昌区珠海组三段为例开展了研究。通过薄片鉴定、阴极发光、电子探针和扫描电镜分析等方法,分析了砂岩储层矿物成分、孔隙类型及储层物性特征,计算了目的层粒间孔面孔率与压实率,对压实作用进行定量评价,确定了区域压实作用强度。研究结果表明珠海组三段总体为强—较强压实,孔隙度与渗透率均较低,主要体现为6号断裂带和断裂间压实较强,南断裂为强压实。压实率与孔隙度、渗透率呈负相关关系,压实作用是导致目的层砂岩储层具有低渗特征的主要原因。本研究建立了珠江口盆地文昌区珠海组三段致密砂岩储层成岩压实作用定量评价的方法。结合前期研究,本文对成岩压实作用程度的评价为该地区油气勘探提供了量化数据。

In order to quantitatively evaluate diagenetic compaction of tight sandstone reservoirs,a case study of the third member of Zhuhai Formation in Wenchang area,Pearl River Mouth Basin was carried out.Based on thin section identification,cathodoluminescence,electron probe and scanning electron microscopy,the mineral composition,pore types and physical properties of sandstone reservoir are analyzed,the pore face ratio and compaction ratio of target layer are calculated,the compaction effect is quantitatively evaluated,and the intensity of regional compaction effect is determined.The results show that the third member of The Zhuhai Formation is generally strongly compacted,with low porosity and permeability,mainly reflected in the strong compaction between the No.6 fault zone and faults,and the south fault is mainly strongly compacted.The compaction rate is negatively correlated with porosity and permeability,the stronger the compaction,the smaller the porosity and the lower the permeability.Through this study,a quantitative evaluation method for diagenetic compaction of tight sandstone reservoirs in the third member of Zhuhai Formation in Wenchang area of Pearl River Mouth Basin was established,which was adapted on the basis of previous studies and analyzed the diagenetic compaction in this area,providing quantitative data for oil and gas exploration in this area.