珠江口盆地白云凹陷恩平组储层成岩作用与孔隙演化定量表征

发布时间：2018-07-05 18:32

本文选题：恩平组 + 孔隙结构　；参考：《天然气地球科学》2017年10期

【摘要】：通过岩石薄片、铸体薄片、荧光薄片、扫描电镜、X-射线衍射、压汞分析和碳氧同位素分析等对珠江口盆地白云凹陷恩平组砂岩储层岩石学特征、孔隙结构、物性特征及影响储层物性的主要成岩作用进行了分析,阐明了相对优质储层形成机理。结果表明:恩平组储层以岩屑砂岩为主,颗粒支撑,孔隙式胶结,胶结物以石英次生加大、含铁方解石、伊利石、高岭石和绿泥石为主;储层孔隙类型以长石和火山岩岩屑遭受溶蚀产生的粒内溶孔为主,部分为粒间溶孔,纵向上在煤系地层附近发育次生孔隙带。储层物性总体具有低孔—低渗特征,压实作用是导致储层物性较差的根本原因,砂岩遭受压实作用损失的孔隙度为12.51%~29.60%,平均为23.99%,达到原始孔隙度的33.53%~79.34%,平均为64.30%,压实减孔强度为39.20%~91.05%,平均值高达81.17%;而钙质砂岩发育段物性差是由中晚期碳酸盐胶结所致,胶结作用损失的孔隙度为2.91%~19.40%,平均值为5.61%,胶结减孔强度为8.95%~60.80%,平均为18.83%;形成次生孔隙的主要原因是有机质热演化过程中释放的有机酸对长石和火山岩屑的溶解,溶蚀作用增加的孔隙度介于3.19%~8.54%之间,平均为5.66%,占岩石总孔隙度的59%~90%,平均为76%。
[Abstract]:The petrological characteristics and pore structure of the sandstone reservoir of Enping formation in Baiyun depression of Pearl River mouth basin were studied by means of thin rock slice, cast thin plate, fluorescence slice, scanning electron microscope (SEM) X-ray diffraction, mercury injection analysis and carbon and oxygen isotope analysis. The characteristics of physical properties and the main diagenesis affecting reservoir physical properties are analyzed, and the formation mechanism of relatively high quality reservoirs is explained. The results show that the reservoir of Enping formation is dominated by lithic sandstone, grain support, pore cementation, quartz secondary enlargement, iron calcite, Illite, kaolinite and chlorite. The reservoir pore type is mainly composed of dissolution pores caused by dissolution of feldspar and volcanic cuttings, some of which are intergranular dissolved pores, and secondary pore zones are developed longitudinally near coal measure strata. The physical properties of the reservoir are characterized by low porosity and low permeability, and compaction is the fundamental reason for the poor physical properties of the reservoir. The porosity of sandstone suffered compaction loss is 12.51% 29.60, with an average of 23.99, reaching 33.53% of the original porosity, 79.34%, with an average of 64.30, and the compaction reducing pore strength is 39.20% 91.05%, the average value is as high as 81.175.The poor physical properties of the calcareous sandstone developmental segment are caused by the carbonate cementation in the middle and late stage. The porosity of the cementation loss is 2.91 ~ 19.40, the average value is 5.61, the strength of the cementation decreasing pore is 8.95 ~ 60.80, and the average is 18.83. The main reason for the formation of secondary pores is the dissolution of organic acids released during the thermal evolution of organic matter to feldspar and volcanic debris. The porosity increased by dissolution is between 3.19% and 8.54%, with an average of 5.66, accounting for 5990% of the total porosity of the rock, with an average of 7650%.
【作者单位】：甘肃省油气资源研究重点实验室/中国科学院油气资源研究重点实验室;中海油研究总院;中国科学院大学;
【基金】：国家科技重大专项(编号:2016ZX05026-007-05)资助
【分类号】：P618.13

【相似文献】