特低渗透砂岩储层可动流体变化特征与差异性成因——以鄂尔多斯盆地延长组为例  

Movable Fluid Changing Characteristics and Diversity Origin of Ultra-Low Permeability Sandstone Reservoir——Take the Yanchang Formation in Ordos Basin as an Example

作　　者：高辉[1] 孙卫[2] 

机构地区：[1]西安石油大学石油工程学院,西安710065 [2]西北大学地质学系,西安710069

出　　处：《地质学报》2010年第8期1223-1230,共8页Acta Geologica Sinica

基　　金：国家重大基础研究发展规划"973"项目(编号2003CB214600);长江学者和创新团队发展计划(编号IRT0559)资助成果

摘　　要：特低渗透砂岩储层微观孔隙结构复杂,流体赋存状态不同于常规储层,利用核磁共振技术对鄂尔多斯盆地延长组3个层位样品的可动流体变化特征与差异性成因进行了分析。结果表明,样品T2谱分布主要表现出4种形态、T2截止值中等—偏高、可动流体参数变化幅度较大;沉积和成岩作用差异导致微观特征参数不同,造成各层位可动流体参数复杂变化;渗透率较小时,可动流体参数变化幅度大,当渗透率增大到一定程度后,可动流体参数数据点收敛,变化幅度减小;储层物性、孔隙(尤其是次生孔隙)发育连通程度、微裂缝的发育程度、粘土矿物的存在形式及其对孔隙的充填程度等微观孔隙结构特征变化是可动流体参数差异性产生的主要原因。可动流体参数本身就是储层诸多微观特征参数的综合反映,应在储层评价中予以考虑。Due to complicated structure of micro-porosity in ultra-low permeability sandstone reservoir, occurrence states of fluid are very different from that of conventional reservoir. This study examined the characteristics and differences of movable fluid changing for the samples from three sequences of the Yangchang Formation in the Ordos basin through NMR technology. The results show that T2 pattern of the samples displays four modes, T2 cutoff value of is moderate-high,with great change of parameters of movable fluid. Difference between deposition and diagenesis can cause the change of micro features, as well as complicated change of movable fluid parameters of each sequence. Movable fluid parameters can change greatly even with low permeability rate; parameters start to converge to a small range of change when permeability increased to a certain degree. Changing features of micro-pore structures, such as physical property, linkage degree of porosity （especially secondary porosity）, and developed degree of microcrack, and occurrence mode and filling degree of clay mineral, are the main reasons to cause deviation of movable fluid parameters. Therefore, the movable fluid parameters, due to its comprehensive reflection to the micro-feature of reservoirs, can be taken into consideration during the evaluation of reservoirs.

关 键 词：可动流体 差异性成因 核磁共振 特低渗透砂岩储层 鄂尔多斯盆地 

分 类 号：P618.13[天文地球—矿床学]