摘要
研究多孔介质中悬浮颗粒沉积引发渗透率衰变过程对地下水回灌、石油开采、污染物迁移等问题具有重要意义。通过理论分析和室内砂箱试验,对基于变孔隙率的多孔介质中悬浮颗粒沉积渗透率衰减模型进行研究。首先,考虑颗粒沉积引起的孔隙率变化,通过Kozeny-Carman方程建立孔隙率与渗透率之间关系,并使用持续注入下颗粒对流–弥散方程确定颗粒分布规律;其次,利用自主研发的砂层迁移–沉积系统进行不同条件下颗粒注入试验,并将试验结果与渗透率衰减模型计算结果进行对比;最后,对模型计算值和试验值之间的误差进行分析。研究结果表明,建立的基于变孔隙率的渗透率衰减模型较好地反映颗粒沉积过程对孔隙结构及渗透率的影响;模型计算的渗透率衰减规律与试验结果吻合较好,验证模型的合理性;模型预测的渗透率衰减值与试验值存在一定误差,主要原因包括模型本身缺陷及试验方法导致的缺陷。研究成果为定量分析颗粒沉积引发地层渗透率变化规律提供了新的思路。
It is of significance to research the permeability reduction process due to particles deposit in porous media, especially in the recharge of groundwater, oil exploration and pollutant transportation engineering. A permeability reduction model of particles deposit in porous medium considering changeable porosity was proposed based on the results of theoretical analysis and sand box tests. Firstly, the change of porosity due to particles deposition was obtained, relationship between porosity and permeability was built using Kozeny-Carman equation, and distribution law of particles was obtained with convection-dispersion equation under continuous injection way. Then, various tests were conducted by the self-developed sand transportation-deposition equipment, and comparisons were made between the calculated and measured results. Finally, the error between predicted and the measured permeability reduction were analyzed. The results revealed that influence on pore structure and permeability due to particles deposition was reflected by the model effectively. The predicted results were close to the measured ones, which show the rationality of the model. Errors between predicted and measured were observed, which were mainly caused by inaccuracy of the proposed model and inherent defect of test methods.
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2016年第A01期3308-3314,共7页
Chinese Journal of Rock Mechanics and Engineering
基金
国家自然科学基金资助项目(41272272
51478368)
湖北省自然科学基金资助项目(132002)~~
关键词
渗流力学
多孔介质
悬浮颗粒
迁移-沉积
变孔隙率
渗透率衰减
砂箱试验
seepage mechanics
porous media
suspended particle
transportation-deposition
changeableporosity
permeability reduction
sand box test
