鄂尔多斯盆地张韩地区长8_2特低渗砂岩储层孔喉结构特征

鄂尔多斯盆地张韩地区长82储层以细粒岩屑长石砂岩为主,为低孔、特低渗储层。孔隙类型多样,以原生粒间孔为主,但孔隙大小分布离散、孔喉半径较小、非均质性强,储层产油能力较差,驱油效率较低。储层物性差是平均喉道半径、中值压力、排驱压力、歪度、最大进汞饱和度、孔隙体积等多种因素共同作用的结果。根据储层岩性、物性、微观孔喉结构参数及产能等资料,将长82岩储层划分为3类,其中Ⅰ类、Ⅱ类是后期开发的优选储层。

Micro-pore throat structure characteristics of ultralow permeability sandstone reservoir in Chang 8_2 reservoir of Zhanghan area,Qrdos Basin

The lithology of Chang 82 reservoir in Zhanghan area,Ordos basin is mainly of fine lithic arkose,low-porosity and ultra-low permeability.The reservoir pore types are various and mainly of primary intergranular pore,while because of the discrete distribution of pore size,smaller pore throat radius and strong heterogeneity,the oil producing capacity and oil displacement efficiency are poor and low.The poor reservoir physical property is the coefficient result of average throat radius,median pressure,driving pressure,partial degrees,the biggest mercury injection saturation and pore volume.According to the lithology,reservoir physical property parameters,micropore throat structure parameters and production capacity,Chang 82 reservoirs are classified into three types,among which type I and type II are optimized for late development.