Clogging caused by coupled grain migration and compaction effect during groundwater recharge for unconsolidated sandstone reservoir in groundwater-source heat pump  

作　　者：Fujian Yang Jing Luo Guiling Wang Hejuan Liu Dawei Hu Hui Zhou 

机构地区：[1]State Key Laboratory of Geomechanics and Geotechnical Engineering,Institute of Rock and Soil Mechanics,Chinese Academy of Sciences,Wuhan,430071,China [2]University of Chinese Academy of Sciences,Beijing,100049,China [3]Sinopec Star Hubei New Energy Development Co.,Ltd.,Wuhan,430010,China [4]Institute of Hydrogeology and Environmental Geology,Chinese Academy of Geological Sciences,Shijiazhuang,050061,China

出　　处：《Journal of Rock Mechanics and Geotechnical Engineering》2024年第8期2947-2959,共13页岩石力学与岩土工程学报（英文版）

基　　金：supported by the National Key Research and Development Program of China(Grant No.2022YFE0137200);National Natural Science Foundation of China(Grant Nos.52309147 and 52179114).

摘　　要：In unconsolidated sandstone reservoirs,presence of numerous movable grains and a complex grain size composition necessitates a clear understanding of the physical clogging process for effective groundwater recharge in groundwater-source heat pump systems.To investigate this,a series of seepage experiments was conducted under in situ stress conditions using unconsolidated sandstone samples with varying grain compositions.The clogging phenomenon arises from the combined effects of grain migration and compaction,wherein the migration of both original and secondary crushed fine-grain particles blocks the seepage channels.Notably,grain composition influences the migration and transport properties of the grains.For samples composed of smaller grains,the apparent permeability demonstrates a transition from stability to decrease.In contrast,samples with larger grains experience a skip at the stability stage and directly enter the decrease stage,with a minor exception of a slight increase observed.Furthermore,a unique failure mode characterized by diameter shrinkage in the upper part of the sample is observed due to the combined effects of grain migration and in situ stress-induced compaction.These testing results contribute to a better understanding of the clogging mechanism caused by the coupled effects of grain migration and compaction during groundwater recharge in unconsolidated sandstone reservoirs used in groundwater-source heat pump systems.

关 键 词：Groundwater-source heat pump CLOGGING Grain migration Compaction effect Groundwater recharge Unconsolidated sandstone 

分 类 号：TU472.9[建筑科学—结构工程]