三维数字岩心建模方法综述

Methods of constructing 3-D digital cores:A review

三维数字岩心在孔隙尺度上描述了岩石的微观结构,已经成为定量分析岩石孔隙结构和岩石物理数值模拟的基础.本文介绍了构建三维数字岩心的两种常用方法;X射线层析扫描成像(CT)和基于岩石二维图像的重建算法,并分析了其优缺点和适用范围.以砂岩为例,定量比较了X射线CT、顺序指示模拟(SIS)、多点地质统计学(MPS)和过程法构建的三维数字岩心.结果表明:过程法重建的三维数字岩心的孔隙连通性与真实岩心最接近,而随机法重建的三维数字岩心孔隙连通性较差.结合复杂储层的岩石物理数值模拟,对三维数字岩心建模技术的发展方向做了展望,认为多尺度、多组分和纳米级三维数字岩心将在岩石物理数值模拟中发挥重要作用.

3-D digital core describes the microstructure of rocks in pore scale, which has been the basis of numerical simulation of rock physics and pore structure analysis. A 3-D digital core can be obtained by X ray computed tomography （CT） or reconstruction algorithm based on 2-D images. The two kinds of methods are introduced detailed. Their advantages, disadvantages, and application scope are discussed. The 3-D digital cores constructed by X-ray CT, Sequential Indicator Simulation （SIS）, Multi-point Statistics（MPS） and Process-based methods are compared quantitatively taking sandstone for example. The results show that Process-based method gives a good representation of connectivity of rock while the digital cores obtained by stochastic methods have poor connectivity of pore space. The trend of building 3-D digital cores is pointed out combining numerical simulation of rock physics for complex reservoir. The multi-scale, multi-component, and nano-scale digital cores will play an active role in the study of rock physics of complex reservoir.