基于择多算子的随机搜索法建立数字岩心的新技术

介绍了用于刻画岩心孔隙空间特征的两点概率函数、线性路径函数,提出了建立数字岩心的新方法——基于择多算子的随机搜索法,系统阐述了该方法的建模理论及基于择多算子的孔隙点、骨架点的随机搜索策略,指出搜索孔隙点、骨架点的择多算子的适宜取值区间分别为9,12]和4,7].研究表明,该法进行数字岩心建模不仅可行而且效果良好.它不受岩性地限制;所建数字岩心的孔隙形态及空间分布特征与真实岩心孔隙相似:尽管岩心含有一定数量的孤立孔隙和岩石颗粒,但其规模很小;岩心具有良好的孔隙连通性、各向同性和渗透性,故可用来研究多孔介质中流体的分布和渗流等问题;由于该法建立的数字岩心的连通性随孔隙度的减小而变差,故该法更适于建立大孔隙度岩心.

A new method of constructing digital core utilizing stochastic search algorithm based on majority operator

Two point probability function and linear path function depicting the characteristics of core’s pore space are introduced. A new method of constructing digital core named stochastic search algorithm based on majority operator is presented. Its theory of constructing digital core and the stochastic search strategy for both pore voxel and grain voxel based on majority operator are illustrated in detail. Good intervals for majority operators when searching pore voxel and grain voxel are suggested to be 9,12], 4,7] respectively. Study shows that this method, without being constrained to lithology, can construct digital core with good quality. The constructed digital core’s pore space gains good topology and distribution which is similar to the genuine rock pore. Although a number of isolated pore and rock phase units appear in the core, their total fraction is quite small. The core’s pore space connection, isotropy and permeability are all good enough to make it a good tool for study of fluid distribution and flow in porous media. As the core’s connectivity becomes poor with its porosity decreasing, the method presented here can be better used for constructing digital core with large porosity.