摘要
针对鄂尔多斯盆地马岭地区长8低渗透砂岩储层的微观非均质性强、微观孔隙结构复杂、可动流体的饱和度低以及流体分布特征差异性明显等问题,利用核磁共振技术对该研究区储层的可动流体进行定量评价,辅助以常规物性、图像孔隙、铸体薄片、扫描电镜、高压压汞和恒速压汞等微观实验分析可动流体的变化特征及差异性成因.研究结果表明:研究区砂岩类型主要为岩屑长石质砂岩;孔隙类型主要为微孔以及溶孔-粒间孔;储层物性越好,可动流体参数变化幅度越大;孔隙半径、喉道半径、孔喉半径比、分选系数、有效孔喉体积以及黏土矿物的充填是影响可动流体变化特征的主控因素.其中微观孔隙结构特征是影响可动流体差异的关键因素;喉道半径、分选系数是影响可动流体饱和度的主要因素;黏土矿物含量的增多对可动流体赋存具有一定的破坏作用.
Low permeability sandstone reservoir of Chang 8 in Maling oilfield, Ordos basin has complex geological features, including strong heterogeneity,complicated microscopic pore structures, low saturation of movable fluids and obviously differences among fluid distribution characteristics. Accordingly, this study used Nuclear Magnetic Resonance(NMR)technique to quantitatively evaluate the movable fluids. Moreover, microscopic experiments were conducted to analyze the characteristics and reasons of differences between movable fluid saturation, including conventional physical property analysis, image porosity measurement, casting thin section observation, SEM analysis, high pressure mercury intrusion test, and constant pressure mercury intrusion test. The results showed that lithic feldspar sandstones were the dominant types of sandstones. Micro-pores and intergranular dissolved pores were the main pore types. Larger physical property variation results in more significant movable fluid saturation variation. The main controlling factors that contribute to the differences of movable fluids saturation are demonstrated to be pore and throat radius, pore throat radius ratio, sorting coefficient, effective pore throat volume, and clay mineral filling. Among them, microscopic pore structure is the key factor to influence the difference of movable fluid, throat radius and sorting coefficient are more dominant factors. The clay minerals have a negative effect on movable fluid saturation.
作者
黎盼
孙卫
李长政
高永利
白云云
杜堃
LI Pan;SUN Wei;LI Chang-zheng;GAO Yong-li;BAI Yun-yun;Du Kun(State Key Laboratory for Continental Dynamics and Department of Geology,Northwest University,Xi'an 710069,China;8th Oil Production Plant of Changqing Oilfield Company,Xi'an 710021 China;College of Petroleum Engineering,Xi'an Shiyou University,Xi'an 710065,China)
出处
《地球物理学进展》
CSCD
北大核心
2018年第6期2394-2402,共9页
Progress in Geophysics
基金
国家科技重大专项大型油气田及煤层气开发(2011ZX05044)
国家青年科学基金项目(41702146)
陕西省青年人才基金(No.2016JQ4022)联合资助
关键词
低渗透砂岩储层
可动流体变化特征
恒速压汞
核磁共振
微观孔隙结构特征
low permeability sandstone reservoir
characteristics of movable fluids
constant pressure mercury
nuclear magnetic resonance
microscopic pore structure
