鄂尔多斯盆地东北缘煤系致密砂岩孔喉结构特征及储层评价  

Pore Throat Structure Characteristics and Reservoir Evaluation of Tight Sandstone in Coal Measures in the Northeast Margin of Ordos Basin

作　　者：孙泽飞 连碧鹏 史建儒 康志帅 杨函 申建 Sun Zefei;Lian Bipeng;Shi Jianru;Kang Zhishuai;Yang Han(Shanxi Geology and Mineral Resources of Science and Technology Evaluation Center,Taiyuan 030000,China;Oil and Gas Resources Development and Management Department of ,.Land and Resources of Shanxi Privinee,Taiyuan 030000,China)

机构地区：[1]山西省地质矿产科技评审中心,太原030000 [2]山西省国土资源厅油气资源开发管理处,太原030000 [3]不详

出　　处：《地质科技情报》2018年第6期130-137,共8页Geological Science and Technology Information

基　　金：国家科技重大专项(2011ZX0503-01-02);国家自然科学基金重点项目(U1361207).

摘　　要：鄂尔多斯盆地东北缘石炭系-二叠系致密砂岩复杂的孔喉结构特征是制约其今后勘探开发的重要因素。为此,通过采用铸体薄片、扫描电镜观察及压汞实验等多种测试手段,系统地分析了煤系致密砂岩储层的孔隙和喉道特征。结果表明:研究区砂岩储层以岩屑砂岩为主;孔隙度主要分布在2%~12%之间,平均6.88%;渗透率主要为0.01×10^(-3)~1×10^(-3)μm^2,平均0.34×10^(-3)μm^2;储层孔隙和喉道类型多样,孔隙类型以溶蚀孔为主,主要组合类型为粒间溶蚀孔+粒内溶蚀孔组合和溶蚀孔+残留粒间组合孔;喉道类型以片状和缩颈型喉道为主,呈单峰和双峰分布;孔喉结构以中孔细喉和中-小孔微细喉为主;微观孔喉结构非均质性强,孔喉结构参数与孔隙度的相关性强于与渗透率的相关性。根据孔喉结构参数与物性的相关性选取最大孔隙半径、歪度和最大进汞饱和度作为储层分类评价指标,结合渗透率和孔隙度,采用模糊数学综合评价方法将研究区储层分为4类,最优储层位于研究区中部、西南部和西北部。The resource of Carboniferous-Permian tight sandstone gas is rich in the northeast margin of Ordos Basin,the key area for further exploration and development.However,the complex pore and throat structure characteristics are the critical factors that restrict the next development.This paper systematically analyzes the pore and throat characteristics of tight sandstone reservoir in coal measures by means of casting thin sections,scanning electron microscope observation and mercury-injection experiment etc.The results show that the reservoir is mainly composed of lithic sandstone.The porosity value of the major pores'ranges from 2% to 12%,with an average of 6.88%,and the main permeability is 0.01×10^-3~1×10^-3μm^2,with an average of 0.34×10^-3~1×10^-3μm^2.The reservoir space is characterized by varied types of pore and throat,and the main pores are dissolution pores including independently developed intergranular dissolution pores and the combination of intergranular dissolution pores and intragranular dissolution pores.The throats are mainly of flaky throats and necking throats,whose distribution characteristics showed unimod al and bimodal.The pore-throat assemblages are dominated by moderate pore-fine throat and small pore-tiny throat.The pore-throat structure of the reservoir is very heterogeneous,and the correlation between its parameters and porosity is stronger than that of permeability.By the correlation between structural parameters of the pore-throat and the physical properties,this paper selects the maximum pore radius,the degree of malformation and the maximum mercury saturation as reservoir classification and evaluation indexes.At the same time combining with the permeability and porosity,the paper divides the reservoir into four categories by using fuzzy mathematics integrated evaluation method.The most favorable reservoirs are located in the middle,southwest and northwest of the region.

关 键 词：鄂尔多斯盆地东北缘 石炭系-二叠系 致密储层 孔喉结构 储层评价 

分 类 号：TE122.23[石油与天然气工程—油气勘探]