粤中地区下侏罗统金鸡组储层特征

Reservoir characteristics of Jinji Formation of Lower Jurassic in central Guangdong

以粤中地区中生界露头剖面的地质调查及采样测试分析为基础,结合已有的资料及前人研究成果,对粤中地区金鸡组储层的岩石学、物性和孔隙结构等进行了初步研究。结果表明,金鸡组储层的岩石类型以灰色、灰白色粗—细粒石英砂岩、含砾砂岩为主;储集空间类型包括溶蚀孔洞、裂缝、粒间孔三大类;储层物性总体表现为中低孔、低渗;排驱压力较高,孔喉半径较小,分选性一般,以细歪度为主,少量的粗歪度,孔隙结构总体较差。利用储层物性和孔隙结构参数,将粤中地区金鸡组砂岩评价为3类储层,其中以Ⅲ和Ⅳ类储层为主。

Based on the field survey and sample testing for the outcrops of Mesozoic, in combination with the results of previous studies, the studies on petrology, pore structure and physical properties of Jinji Formation in central Guangdong are carried out. The result shows that the reservoir rocks are mainly composed of grey-white coarse-fine quartz sandstone and conglomerate-bearing sandstone; the reservoir space comprises cavity, fractures and intergranular porosity; the physical property is generally characterized by moderate-low porosity and low permeability, high displacement pressure, small pore throat radius, general sorting, mainly fine skewness and slightly coarse skewness ,thus, the pore structures are poor. According to the parameters of physical properties of the reservoir and pore structure, the sandstone reservoirs of Jinji Formation are divided into three types, and the type Ⅲ and type Ⅳ are the dominant ones.