致密砂岩储层孔喉结构差异对可动流体赋存特征的影响——以苏里格气田东区和西区盒8储层为例  

Influence of Pore-Throat Structure Differences on Occurrence Characteristics of Movable Fluid in Tight Sandstone Reservoirs:An Example of the He 8^(th) Member of Permian Xiashihezi Formation in the East and West of the Sulige Gas Field

作　　者：吴育平 孙卫[1] 杜堃 黎盼 屈怡倩 WU Yuping;SUN Wei;DU Kun;LI Pan;QU Yiqian(Department of Geology,State Key Laboratory of Continental Dynamics,Northwest University,Xi'an,Shaanxi 710069)

机构地区：[1]西北大学地质学系大陆动力学国家重点实验室,陕西西安710069

出　　处：《地质与勘探》2019年第1期212-222,共11页Geology and Exploration

基　　金：国家科技重大专项大型油气田及煤层气开发(编号:2011ZX05044)资助

摘　　要：为探讨致密砂岩储层的微观孔喉结构参数对可动流体赋存特征的影响,本文以苏里格气田东区和西区盒8储层为例,利用铸体薄片、扫描电镜、恒速压汞及核磁共振等实验方法,对比并分析了微观孔喉结构差异对可动流体赋存特征的影响。结果表明:喉道大小及分布特征是造成致密砂岩储层渗流能力不同的主要因素,喉道半径分布范围越宽,峰值越大,渗流能力就越强;相反,喉道半径分布范围越窄,峰值越小,渗流能力就越弱。致密砂岩储层在可动流体赋存特征方面的差异本质是源于喉道发育程度不同,特别是在孔喉结构非均质性越强的储层中,喉道对可动流体的赋存特征影响越为显著。致密砂岩储层的有效孔隙体积相比于有效喉道体积对可动流体的影响更大,也更能表征流体的赋存状态。The objective of this work was to explore the influence of microscopic pore structure parameters of tight sandstone reservoirs on the occurrence characteristics of movable fluid. Taken the 8th member of permian Xiashihezi Formation in the eastern and western regions of the Sulige gas field as an example,the effects of microscopic pore structure on the occurrence characteristics of movable fluid were analyzed and compared by using the methods of casting thin section,SEM,constant pressure mercury injection and nuclear magnetic resonance. The results show that the throat size and distribution are the main factors that cause the seepage capacity of tight sandstone reservoirs. The wider the throat radius distribution is and the larger the peak value is,the stronger the penetration is;on the contrary,the narrower the throat radius distribution is and the smaller the peak value is,the weaker the penetration is. The difference in the occurrence characteristics of movable fluid is essentially due to the different degrees of throat development. The influence of throats on the occurrence characteristics of the movable fluid is more significant,especially in the reservoir with stronger pore-throat structure heterogeneity. The effective pore volume of tight sandstone reservoirs has a greater influence on the movable fluid than the effective throat volume,and can better characterize the occurrence of fluid.

关 键 词：致密砂岩储层 苏里格气田 孔隙结构 可动流体 

分 类 号：P618.13[天文地球—矿床学]