致密砂岩储层孔喉结构特征及流体可动性影响因素  

Pore-throat structure characteristics and influencing factors for fluid mobility of tight sandstone reservoirs

作　　者：康小斌[1] 闫钰琦 屈亚宁 刘松 KANG Xiaobin;YAN Yuqi;QU Yaning;LIU Song(Water Injection Project Area Management Headquarters of Yanchang Oilfield Co.,Ltd.,Yan’an 716001,China;Dingbian Oil Production Plant of Yanchang Oilfield Co.,Ltd.,Dingbian,718699,China;Guizhou Energy Industry Research Institute Co.,Ltd.,Guiyang 550025,China)

机构地区：[1]延长油田股份有限公司注水项目区管理指挥部,陕西延安716001 [2]延长油田股份有限公司定边采油厂,陕西定边718699 [3]贵州能源产业研究院有限公司,贵州贵阳550025

出　　处：《大庆石油地质与开发》2024年第5期79-88,共10页Petroleum Geology & Oilfield Development in Daqing

基　　金：贵州省科技重大专项“贵州省页岩气效益开发关键技术及工程实验”(2022ZD005);贵州省科技支撑项目“常压页岩气排水采气技术及装备研发”(2022010)。

摘　　要：为了明确核磁共振T2谱与孔喉半径的转换及优选评价储层流体可动性参数,选取鄂尔多斯盆地定边地区延长组长7段14块致密砂岩样品,开展了储层物性、高压压汞及核磁共振等实验,分析储层孔喉结构特征及其对流体可动性的影响。结果表明:研究区致密砂岩储层孔喉结构可划分为Ⅰ类、Ⅱ类、Ⅲ类和Ⅳ类,对应的平均孔喉半径逐渐减小,且储层物性和流体可动性依次变差;通过高压压汞来转换核磁共振可动流体T2谱可以精确表征半径为0.001~4μm的全孔径孔喉大小分布以及可动流体赋存特征;可动流体有效孔隙度可定量表示可动流体占据岩样内有效孔隙空间的大小,能够有效评价储层流体的可动性;致密砂岩储层流体可动性主要受控于孔喉结构参数,且受储层物性和黏土矿物含量的综合影响。研究成果可为致密砂岩储层质量评价和开发潜力预测提供依据。In order to clarify the conversion from NMR T2 spectrum to pore-throat radius and optimize parameters for evaluating reservoir fluid mobility,14 tight sandstone samples are selected from Chang 7 member of Yanchang For-mation in Dingbian area of Ordos Basin to carry out experiments of reservoir property,high-pressure mercury injec-tion and NMR,and thus to analyze pore-throat structure characteristics of reservoirs and their influence on fluid mo-bility.The results show that pore-throat structure of tight sandstone reservoirs in studied area are divided into TypeⅠ,TypeⅡ,TypeⅢand TypeⅣ,with gradually decreasing corresponding average pore-throat radius,and succes-sive lowering reservoir properties and fluid mobility.NMR movable fluid T2 spectrum converted by high-pressure mercury injection can accurately characterize full pore-throat size distribution with a radius of 0.001~4μm and oc-currence characteristics of movable fluid.Effective porosity of movable fluids can quantitatively express the size of effective pore space occupied by movable fluids in rock samples,and can effectively evaluate reservoir fluid mobili-ty.The fluid mobility of tight sandstone reservoirs are mainly controlled by pore-throat structure parameters,and are comprehensively affected by reservoir properties and clay mineral content.The research provides basis for quali-ty evaluation and development potential prediction of tight sandstone reservoirs.

关 键 词：孔喉结构 流体可动性 核磁共振 高压压汞 可动流体T2谱 

分 类 号：TE122.23[石油与天然气工程—油气勘探]