摘要
储层出砂过程中砂岩颗粒的离散与其细观结构性有密切关系。以胶结砂岩为研究对象,基于三维颗粒流数值模型(PFC3D)建立4种不同粒度分布的数值模型,模拟剪切过程的砂岩力学响应,研究不同粒度分布的砂岩体应力比、体应变、配位数和黏结破坏与轴应变之间的关系。结果表明:粒度分布对砂岩力学特性的影响较大,仅基于随机方法产生颗粒建立的数值模型不能完全代表实际砂岩的物理结构。须根据实测的砂岩粒度分布建立三维数值模型,才能准确描述储层砂岩的力学特性。粒径越小,连接的颗粒越少,自由度越大,开采中成为离散颗粒的可能性越大。
For sand production in the sandstone reservoir,the meso-structure plays an important role in the dislodgement of the sand particles. The cemented sandstone as a case study,four numerical models considering different particle size distribution based on 3D particle flow code（ PFC3D） were developed to simulate the mechanical response in the shearing test. In addition,the stress ratio,volume strain,coordination number and broken bonds changing with the axial strain were analyzed. The results show that the particle size distribution has great influence on the mechanical characteristics of the sand,so the numerical model based on random method to generate particles cannot completely represent the physical structure of the practical sandstone. Therefore,the numerical model based on measured particle size distribution can correctly describe the mechanical response of the reservoir sandstone. The smaller particles have less connectivity with other particles,so the particles with more freedom more likely become the dislodged particles when extracting.
出处
《中国石油大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2014年第5期142-148,共7页
Journal of China University of Petroleum(Edition of Natural Science)
基金
国家重点基础研究发展计划'973'项目(2014CB046903)
国家自然科学基金项目(51478065
51109231)
中央高校基本科研业务费项目(106112013CDJZR200004
106112014CDJZR200014)
关键词
细观结构
胶结砂岩
粒度分布
三维颗粒流数值模型
力学特性
meso-structure
cemented sandstone
particle size distribution
3D particle flow code
mechanical characteristics
