文献类型：期刊文献

英文题名：Capillary trapping induced slow evaporation in nanochannels

作者：Bao, Bo[1,2];Qiu, Junjie[1,2];Liu, Fen[1,2];Fan, Qiyue[1,2];Luo, Wei[1,2];Zhao, Shuangliang[1,2]

机构：[1]East China Univ Sci & Technol, State Key Lab Chem Engn, Shanghai 200237, Peoples R China;[2]East China Univ Sci & Technol, Sch Chem Engn, Shanghai 200237, Peoples R China

年份：2021

卷号：196

外文期刊名：JOURNAL OF PETROLEUM SCIENCE AND ENGINEERING

收录：;EI(收录号：20204609483140);WOS:【SCI-EXPANDED(收录号:WOS:000600808100217)】；

基金：We gratefully acknowledge the generous support from National Natural Science Foundation of China (No. 21808056) and PetroChina Innovation Foundation (2019D-5007-0208).

语种：英文

外文关键词：Low-permeability reservoirs; Capillary trapping; Evaporation; Phase behaviors; Nanoconfinement; Nanofluidics

摘要：Unconventional reservoirs are massive and providing an increasing share of global energy with a broad group of stakeholders in academia, industry and government. The size of pores in unconventional reservoirs can be down to nanometers, necessitating a deeper fundamental understanding of fluid phase properties at nanoscale. In this paper, we investigate capillary trapping induced slow evaporation of n-pentane in nanochannel arrays through isothermal pressure drawdown to mimic the hydrocarbon release in nanopores of low-permeability reservoirs. Importantly, the capillary trapping forms during a slow reservoir pressure reduction process and significantly impedes liquid evaporation. Compared to the evaporation case without any capillary trapping, the global evaporation rate is similar to 16 times lower, which unfavorably affects gas recovery. In addition, we observe liquid corner flow in assisting evaporation in nanochannel, providing important experimental evidence towards previous theoretical study. In brief, our work reveals a type of anomalous evaporation at nanoscale that is fundamentally relevant to shale gas recovery. The experimental and modeling finding indicates that regulating pressure drawdown at an appropriate rate plays a key role in efficiently extracting shale gas.