碳酸盐岩储层微观孔隙结构静态表征与动态评价——以鄂尔多斯盆地西北部马五段为例  

Static characterization and dynamic evaluation of micro pore structure of carbonate reservoir:a case study of Majiagou Member 5 in northwestern Ordos Basin

作　　者：魏丽 马尚伟 王震亮[4] 王一军 WEI Li;MA Shangwei;WANG Zhenliang;WANG Yijun(Shaanxi Center of Geological Survey and Planning Research;Xi’an Center of Geological Survey,China Geological Survey;不详)

机构地区：[1]陕西省地质调查规划研究中心(陕西省地质勘查基金中心) [2]陕西省地质调查院 [3]中国地质调查局西安地质调查中心 [4]西北大学地质学系 [5]中国石油集团东方地球物理公司研究院长庆分院

出　　处：《海相油气地质》2021年第2期131-140,共10页Marine Origin Petroleum Geology

基　　金：国家自然科学基金项目“延安地区下古生界碳酸盐岩天然气的成藏过程和机理”(编号:41172122);陕西省地质勘查基金项目“秦岭成矿带地质矿产勘查成果集成与选区研究”(编号:61201506280)联合资助。

摘　　要：在岩心、铸体薄片、扫描电镜观察和物性分析的基础上,应用高压压汞、气水相渗、核磁共振等分析测试方法,对鄂尔多斯盆地西北部下奥陶统马五段储层微观孔隙结构进行了静态表征与动态评价。鄂尔多斯盆地西北部马五段的岩性主要为白云岩,孔隙度、渗透率较低,对油气储集和渗流具有较大意义的储集空间为晶间溶孔、溶蚀孔洞、铸模孔和裂缝。依据压汞参数和毛管压力曲线形态,将马五段储层孔隙结构划分为4种类型。选取孔隙度、渗透率、主流孔喉半径、最大进汞饱和度、等渗点相对渗透率、可动流体饱和度、试气产量和孔喉组合类型等8项参数,建立了研究区马五段碳酸盐岩储层微观孔隙结构分类评价标准。Ⅰ类、Ⅱ类储层的溶蚀孔洞、晶间溶孔、裂缝发育,以中大孔喉为主,孔隙度>5.5%,渗透率>0.1×10^(-3)μm^(2),最大进汞饱和度>70%,等渗点相对渗透率≥0.05×10^(-3)μm^(2),可动流体饱和度>60%,经压裂改造可获工业气流,是勘探开发的主要目标。Based on the observation of core,casting thin section and scanning electron microscope and analysis of physical property,static characterization and dynamic evaluation of micro pore structure of carbonate reservoir of Majiagou Member 5 in northwestern Ordos Basin are carried out by means of high pressure mercury injection test,gaswater relative permeability test and nuclear magnetic resonance test.The results show that the lithology of Majiagou Member 5 in northwest of Ordos Basin is mainly dolomite with low porosity and low permeability.The reservoir spaces with great significance for oil and gas reservoir and seepage are inter-granular solution pore,solution pore,mold pore and fractures.According to mercury injection parameters and capillary pressure curve shape,the pore structure types of Majiagou Member 5 are divided into four types.Eight parameters,such as porosity,permeability,main pore throat radius,maximum mercury saturation,relative permeability at the same permeability point,movable fluid saturation,gas testing production and types of pore throat assemblage,are selected to establish the classification and evaluation criteria for the micro pore structure of carbonate reservoir of Majiagou Member 5.The solution pores,inter-granular solution pores and fractures of classⅠand classⅡreservoirs are well developed,with medium and large pore throat,porosity>5.5%,permeability>0.1×10^(-3)μm^(2),maximum mercury saturation>70%,relative permeability at the same permeability point≥0.05×10^(-3)μm^(2),movable fluid saturation>60%.Reservoirs of classⅠandⅡare the main goals of exploration and development,in which industrial gas flow can be obtained through fracturing transformation.

关 键 词：微观孔隙结构 碳酸盐岩储层 马家沟组 奥陶系 鄂尔多斯盆地 

分 类 号：TE122.2[石油与天然气工程—油气勘探]