渤中凹陷深层特低孔特低渗砂砾岩储层储集空间精细表征  

Fine characterization of the reservoir space in deep ultra-low porosity and ultra-low permeability glutenite in Bozhong Sag

作　　者：张铜耀 郝鹏 Zhang Tongyao;Hao Peng(CNOOC Experimental Center,CNOOC Ener Tech-Drilling&Production Co.,Tianjin 300452,China)

机构地区：[1]中海油能源发展股份有限公司工程技术分公司中海油实验中心,天津300452

出　　处：《地质科技通报》2020年第4期117-124,共8页Bulletin of Geological Science and Technology

基　　金：中海油能源发展股份有限公司科研项目“基于数字岩心技术的复杂储层表征与渗流机理研究”。

摘　　要：利用自动矿物定量识别系统(QEMSCAN)、二维大尺寸背散射图像拼接技术(MAPS)、多尺度微米CT、铸体薄片、恒速压汞等实验技术,对渤中凹陷深层孔店组特低孔特低渗砂砾岩储层的储集空间进行了二维、三维多尺度精细表征,并系统研究了砂砾岩储层渗流能力影响因素。实验结果显示,研究区砂砾岩孔隙毫米-微米-纳米级多尺度连续分布,孔隙度相对大的储层,孔径分布范围较宽,储层粒间原生孔、粒间溶蚀孔等大孔隙占比较高,粒内溶蚀孔、晶间孔占比较低。基于三维孔喉网络模型,孔隙主要半径分布区间为1.5~60μm,喉道半径分布在0.5~8.0μm之间,孔喉连通性的分布形态有条带状、连片状、孤立状,储集性较好的储层孔喉在三维空间多为连片状,渗透率相对较差的储层孤立状的大孔较多。孔隙型储层的渗透率与孔喉形态、喉道半径、配位数等参数密切相关。裂缝明显改善了砂砾岩的物性,也为酸性流体对储层的溶蚀提供了有效通道,导致溶蚀孔隙相对发育。综合研究认为,渤中凹陷深层砂砾岩储层的渗流能力受裂缝发育程度、孔喉连通性双重控制,储层中黏土矿物和碳酸盐矿物胶结对孔隙结构、储层渗流能力有重要影响。With the application of automatic mineral quantitative identification system(QEMSCAN),modular automated processing system(MPAS),multi-scale micro CT,thin section identification,constant-rate mercury injection and other experimental techniques,the reservoir space in deep ultra-low porosity and ultra-low permeability glutenite of Kongdian Formation in the Bozhong Sag were characterized in two and three dimensions,and the influencing factors of the permeability of glutenite reservoir were studied in detail.The experimental results show that the glutenite in the study area has millimeter,micron and nanometer pores.For the samples with relatively large porosity,there are relatively more interparticle pores and interparticle dissolution pores in the reservoir.On the basis of the three-dimensional pore-throat network model,the most part of the pore radius ranges from 0.3 to 10μm and the roar channel radius mainly ranges from 0.5 to 8.0μm.The pore-throat distribution is mainly three forms:banded,contiguous and isolated.The pore throats of reservoirs with good reservoir properties are mostly continuous in three-dimensional space,and the reservoirs with relatively poor permeability contain more isolated large pores.The fluid mobility of porous reservoir is closely related to throat radius,pore-throat shape,coordination number and other parameters.Fractures improve the physical properties of glutenite obviously,and also provide a channel for the acid solution to the reservoir and promotes the formation of dissolution pores.Comprehensive study showed that the fluid flow of the glutenite in the Bozhong Sag is controlled by the fracture and the pore-throat connectivity.The cementation of clay and carbonate minerals in the reservoir has an important influence on the pore structure and permeability.

关 键 词：砂砾岩 孔隙结构 三维孔喉网络模型 数字岩心技术 渗流能力 特低孔特低渗储层 渤中凹陷 

分 类 号：P618.13[天文地球—矿床学]