介绍核磁共振测井(NMR)在复杂孔隙结构储层评价中的应用.详细分析利用核磁共振的弛豫特性和扩散特性计算渗透率的模型优缺点.Coates模型和SDR模型比常规经验公式计算渗透率更准确,但大量岩心实验数据表明它们并不适用于特低渗透储层.提出一种新的定量评价物理函数——孔隙空间集中分布模型,它通过描述T2分布中可动流体体积分布的均一性,准确计算出低孔隙度低渗透率储层的渗透率.岩心数据计算表明,孔隙空间集中分布模型系数C与岩心渗透率具有很好的负相关关系,C值越小,表明孔径分布的集中程度越低,渗透性越好.岩心数据分析比较表明,该模型比经典核磁共振测井渗透率评价模型精度更高,对于定量描述复杂孔隙结构储层的渗透性具有很好适用性.%Introduced is the application of Nuclear Magnetic Resonance (NMR) logging in permeability evaluation of complex pore structure reservoir. Analyzed in detail are advantages and disadvantages of permeability calculation methods, with NMR relaxation property and diffusion property. Coates model and SDR model are more accurate in permeability calculation than conventional empirical formulas, but a large number of core experimental data show that they are not suitable for ultra-low permeability reservoir. Put forward is a new permeability quantitativernevaluation method-pore space centralized distribution model, which could accurately calculaternpermeability of low porosity and low permeability reservoir by describing movable fluid volume distribution homogeneity in T2 distribution. Core data calculation shows that factor C in pore space centralized distribution model has well negative correlation with core permeability. Low factor C value indicates low concentration of pore size distribution, and better permeability. Core data analyze and comparison manifest that the pore space centralized distribution model has higher accuracy and is suitable for permeability quantitative evaluation of reservoir with complex pore structure.
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