直罗油田延9储层微观孔隙结构特征

Microscopic Pore Structure Characteristics of Yan 9 Reservoir in Zhiluo Oilfield

利用铸体薄片、扫描电镜、物性和恒速压汞等分析化验资料,对延9储层微观孔隙结构特征进行了深入的研究。结果表明:直罗油田延9储层属于中孔、中低渗储层,孔隙以粒间溶孔、剩余原生粒间孔和粒内溶孔为主,属中-小孔、中细喉道类型,孔喉分选性一般,连通性一般。根据孔隙结构特征相关参数将毛管压力曲线分为4类,研究区主要以Ⅲ类为主。从Ⅰ类到Ⅳ类,排驱压力和中值压力逐渐增大,中值半径和平均喉道半径逐渐减小,反映出储层的孔隙结构和渗流能力由好变差。孔隙结构特征参数与物性相关性的研究表明,物性是排驱压力、中值压力、中值半径及孔隙结构系数等多种因素综合作用的结果。

By the data of cast thin section, scanning electron microscope, physical property and constantrate mercury injection, the microscopic pore structure characteristics of Yan 9 reservoir in Zhiluo Oilfield are studied. The result shows that Yan 9 reservoir belongs to middle porosity and middlelow permeability reservoir in Zhiluo Oilfield. The main pore types of the reservoir include intergranular dissolved pore, residual intergranular pore and in tragranular dissolved pore. The pore and throat have general sorting and communication. The capillary pressurecurve is divided into I , II, m, iv types according to the characteristic parameters of pore structure. The type m are the main types in the study area. With capillary pressure curve changing from I type to iv type, the driving pressure and Pc50 increase gradually, and Rcs0 and average pore throat radius decrease gradually, which reflects that pore structure and reservoir property change from good to poor. By comprehensive research of the relationship between characteristic parameters of pore structure and property parameters, it is shown that reservoir property is the result of driving pressure, Pc50, r50 and pore structure parameters and so on.