摘要
低渗煤体微观渗流特性研究对煤层注水增注、防治瓦斯灾害具有重要价值,物理模型仿真试验是开展此研究的重要途径之一。为研究煤体孔隙微观尺度下液体的初始渗流特性,以微流控技术为基础,制作替代煤体孔隙的等效毛管束模型,构建了微观渗流可视化试验平台,开展了不同孔隙尺寸、不同流体的渗流模型试验,分析了渗流流量、渗流压力、孔径尺度、润湿性等多个参量对渗流特性的影响。研究结果表明:①渗流过程不同位置孔隙渗流的活跃性差异较大,模型中间位置渗流更活跃;渗流初始流量越大,参与渗流通道数目越多。渗流初始流量与毛细管内流体体积成正比;②初始流量一定时,不同孔径内渗流压力和时间关系相同,即渗流压力随时间增加增大。初始渗流流量越大,体系渗流压力也越大;毛管束内渗流呈现较明显的非线性渗流特征;③不同的模型孔径尺度下,渗流流量与渗流压力关系十分接近;3种孔径尺度的毛管束模型中去离子水的流量和压力都呈现出不同程度的非线性特征,且孔径尺度越小,非线性程度越强;④在流体润湿性的影响上,不同模型孔径的试验结果都表明,润湿性好的流体在毛细孔隙模型中渗流压力更小。相较于孔径尺度,渗流初始流量对流体渗流压力的影响更大。
Research on the micro-seepage characteristics of low-permeability coal bodies is of great value to coal seam water injection and gas disaster prevention.Physical model simulation experiments are one of the important ways to carry out this research.In order to study the initial seepage characteristics of the liquid at the microscopic scale of coal pores,this paper uses microfluidic technology as the basis to make an equivalent capillary bundle model to replace coal pores,and build a microscopic seepage visualization experimental platform.We carried out seepage model experiments with different pore sizes and different fluids,and analyzed the influence of multiple parameters such as seepage flow rate,seepage pressure,pore size,wettability,etc.on seepage characteristics.The research results show that:①The ac⁃tivity of pore seepage at different positions in the seepage process is quite different,and the seepage at the middle of the model is more ac⁃tive;the larger the initial flow of seepage,the more the number of channels participating in seepage.The initial flow of seepage is propor⁃tional to the volume of fluid in the capillary;②When the initial flow is constant,the relationship between seepage pressure and time in different apertures is the same,that is,seepage pressure increases with time.The larger the initial seepage flow rate,the higher the system seepage pressure;the seepage flow in the capillary bundle shows obvious nonlinear seepage characteristics;③The relationship be⁃tween seepage flow and seepage pressure is very close under different model pore sizes;The flow and pressure of deionized water in the tube bundle model show different degrees of non-linear characteristics,and the smaller the pore size,the stronger the degree of non-line⁃arity;④In terms of the influence of fluid wettability,the experimental results of different model pores are all It shows that the fluid with good wettability has lower seepage pressure in the capillary pore model.Compared with the pore size,the initial flow rate of seepage has a greater influence on fluid seepage pressure.
作者
王刚
李艳青
刘世民
李怀兴
商荦真
陈建
WANG Gang;LI Yanqing;LIU Shimin;LI Huaixing;SHANG Luozhen;CHEN Jian(State Key Laboratory of Mining Disaster Prevention and Control Co-founded by Shandong Province and the Ministry of Science and Technology,Shandong University of Science and Technology,Qingdao 266590,China;College of Safety and Environmental Engineering,Shandong University of Science and Technology,Qingdao 266590,China;Earth and Mineral Sciences,State College The Pennsylvania State University,PA 16802,USA)
出处
《煤炭科学技术》
CAS
CSCD
北大核心
2022年第2期147-153,共7页
Coal Science and Technology
基金
国家自然科学基金资助项目(51974176)
山东省自然科学杰出青年基金资助项目(ZR2020JQ22)
山东省高等学校青创科技支持计划资助项目(2019KJH006)。
关键词
煤层注水
微观孔隙
等效毛管束
渗流特性
可视化研究
coal seam water injection
microscopic pores
equivalent tube bundle
seepage characteristics
visualization research
