惠州凹陷西江-惠州转换带文昌组储层特征及控制因素研究

Reservoir characteristics and controlling factors of Wenchang Formation in Xijiang-Huizhou transform zone,Huizhou Sag

惠州凹陷古近系文昌组储层是近年来珠江口盆地的重点勘探层系。采用铸体薄片、扫描电镜和物性分析等资料,对西江-惠州转换带文昌组储层的岩石学特征、储集空间类型、孔隙结构特征、物性特征及主要控制因素进行了深入研究。结果表明:孔隙类型以粒间溶蚀扩大孔和原生粒间孔为主,部分层位大量高岭石沉淀在溶蚀孔和原生孔中,产生较多高岭石晶间微孔;显孔发育的储层孔隙结构相对较好;填隙物中泥质、碳酸盐含量及长石含量的高低对储层影响较大;压实作用产生的压碎缝对深部储层的渗透率贡献较大;早期形成的伊/蒙混层黏土膜有抗压实作用,在保存粒间孔的同时也抑制了颗粒溶蚀作用的发生。

The reservoir of Wenchang Formation in Huizhou Sag is the key exploration strata of Paleogene in Pearl River Mouth Basin. Based on the data of thin section, scanning electron microscope and properties, this paper studied the petrologic characteristics, reservoir space, pore structure, properties and main controlling factors of the reservoir of Wenchang Formation in Xijiang-Huizhou transform zone. The result shows that pore types are mainly intergranular corrosion expansion pores and primary intergranular pores, and a great deal of kaolinite was precipitated in corrosion pores and primary pores and produce intercrystalline pores in some strata. The pore structure is better in the reservoir which the intercrystalline pores are not developed. The content of clay, carbonate and feldspar in the fillings are the main controlling factors. The crush fracture formed by compaction is the major contribution to the permeability of deep reservoir. The clay film of the illite-smectite mixed layer which is formed early can resist the compaction and inhibit the corrosion on the grain, preserving some intergranular pores.