过程法数字岩心建模与弹性参数模拟研究

Study on processed based method digital rock modeling and elastic property simulation

在数字岩石物理中数字岩心是弹性参数模拟的基础,现有的数字岩心建模方法虽然较多,但一般不能满足弹性参数模拟对骨架所提出的要求.过程法以岩石粒径分布曲线为约束条件构建数字岩心,是一种比较灵活的数字岩心建模方法.本文根据前人研究结果在过程法的压实过程中用一面状像素层表示颗粒与颗粒间的接触边界,使相邻的骨架颗粒能够相互区分,提高了数字岩心骨架结构的精细程度.在弹性参数模拟中,当变化数字岩心中的颗粒、颗粒接触边界和胶结物的弹性模量时,数字岩心的弹性模量发生相应的变化.数字岩心弹性模量的变化量与组成物质的体积含量及其弹性模量赋值有关.这说明能够利用数字岩石物理研究各种地质和环境因素对岩石弹性性质的影响.进一步分析认为,目前的建模方法对数字岩心的定义还不够充分,利用数字岩石物理解决实际地质问题尚有难度.

Digital rock is the base of elastic property simulation in digital rock physics. There exist several kinds of digital rock reconstruction method, but generally they can not meet the requirements of elastic property simulation on solid matrix.Processed based method is a flexible digital rock modeling method which constructing digital rock from grain diameter distribution curves. In this article a new technique of processed based method is developed,that the grain to grain contact boundary is represented by voxel-surface,by which different grains are distinguished, thus more details are displayed in the matrix. The elastic moduli of the digital rock varies as the elastic moduli of grain,grain to grain contact boundary and cement change. The variation is related to volumes of different material phases and their elastic moduli. This indicates that the digital rock can be used for studying the effect of geological and environmental factors on the elasticity of rock.Further analysis concludes that method to define digital rock is not enough,and to solve geological problem with current digital rock modeling methods is somewhat difficult.