文献类型：期刊文献

英文题名：Spontaneous Imbibition in Nanomatrix-Fracture of Low Permeability Using Multiscale Nanofluidic Chips

作者：Qin, Wanjun[1];Guo, Yaohao[1];Sun, Linghui[2];Shi, Jiawei[1];Bao, Bo[1]

机构：[1]East China Univ Sci & Technol, Sch Chem Engn, Shanghai 200237, Peoples R China;[2]Res Ctr Enhanced Oil Recovery China Petr Explorat, Dev Res Inst, Beijing 10083, Peoples R China

年份：2023

卷号：39

期号：49

起止页码：17972

外文期刊名：LANGMUIR

收录：;EI(收录号：20235015216923);WOS:【SCI-EXPANDED(收录号:WOS:001124977800001)】；

基金：This work was financially supported by National Natural Science Foundation of China (no. 22278128) and China Scholarship Council (CSC, no. 202206740011). This project was also funded by a research grant from PetroChina.

语种：英文

外文关键词：Nanofluidics - Nanopores - Real time systems

摘要：Spontaneous imbibition has garnered increasing attention as an attractive mechanism for developing tight reservoirs. Despite valuable insights from previous experiments, there remains a lack of understanding regarding the imbibition process within multiscale nanopore-fracture networks. In this work, we devised an innovative multiscale model incorporating over 105 nanochannels and integrating a microfracture network to explore the complex imbibition behavior in tight formations. Additionally, fracture-free nanomatrix models with low permeability were developed for comparative discussions. The results show that the Lucas-Washburn equation remains valid at the tremendous fracture-free nanopore networks under the confinement of 500 nm, with a relative deviation of +/- 6%. The nanomatrix's heterogeneity hinders the imbibition rate, resulting in a reduction of 4.6 to 10.8% in the imbibition slope. The viscosity plays a dominant role in the change of imbibition slope as temperature varies. Our experiments also found that the interactions between the nanomatrix and bulk fracture complicate the imbibition process. A single wetting front no longer applies in the nanomatrix-fracture networks. Differing fracture/microchannel connectivity leads to disparities in macroscopic patterns, saturation rates, and flow directions. The spatial arrangement of fractures significantly impacts the imbibition time. Overall, this work based on nanofluidic techniques systematically explores the effects of matrix heterogeneity, temperature, and fractures on the imbibition process. The real-time in situ visualization of fluid distribution in multiscale matrix-fracture systems has been achieved, which offers theoretical guidance for practical engineering applications.