中文摘要：

根据核磁共振弛豫机制,基于三维数字岩心技术建立一种估算砂岩核磁共振横向弛豫（T2）谱的新方法。采用过程模拟法重建砂岩三维数字岩心,通过Delaunay剖分将砂岩微观孔隙结构划分为多个四面体孔隙单元,再用几何方法和Monte Carlo方法相结合求出每个孔隙单元的表面积与体积之比（S/V）,进而获得砂岩模拟的核磁T2谱。经过大量模拟试验筛选参数,减小计算误差。考虑单峰态和双峰态核磁T2谱,模拟结果和实验结果基本吻合。该方法有助于研究粒度分布、孔隙结构等对岩石核磁共振响应的影响。

英文摘要：

Based on nuclear magnetic resonance（NMR） relaxation mechanism and three-dimensional digital core technology,a new method of estimating the spectrum of sandstone transverse relaxation time（T2） is established.A process-based method was used to reconstruct 3D digital rock models of sandstone.Sandstone microstructures were divided into tetrahedral pore units using Delaunay tessellation.Considering the geometry and using a Monte Carlo approach,the surface-to-volume ratio（S/V） of each pore unit was calculated,and then the T2 spectrum of sandstone could be simulated.After a large number of simulations,suitable parameters were selected in order to reduce calculation errors.Unimodal and bimodal T2 spectrum were considered;both results agreed well with laboratory tests.This new method is helpful in studies of different NMR response effects with varying grain sizes or pore structures.