Experimental research on microscopic displacement mechanism of CO2-water alternative flooding in low permeability reservoir

International Conference on Energy Engineering and Environmental Protection 2017

能源学;生态环境科学

Han, Hongyan^1 ; Zhu, Weiyao^1 ; Long, Yunqian^2 ; Song, Hongqing^1 ; Huang, Kun^1

School of Civil and Recource Engineering, University of Science and Technology Beijing, Beijing

100083, China^1

Innovation Application Institute, Zhejiang Ocean University, Zhoushan

316022, China^2

关键词: Displacement process;    Experimental methods;    Experimental research;    Formation condition;    Image processing technique;    Microscopic displacement;    Microscopic visualization;    Oil-displacement efficiency;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/121/2/022025/pdf
DOI  :  10.1088/1755-1315/121/2/022025

学科分类：环境科学（综合）

来源: IOP

【 摘 要 】

This paper provides an experimental method to deal with the problems of low oil recovery ratio faced with water flooding utilizing the CO2/water alternate displacement technology. A series of CO2/water alternate flooding experiments were carried out under 60°C and 18.4MPa using high temperature / pressure microscopic visualization simulation system. Then, we used the image processing technique and software to analyze the proportion of remaining oil in the displacement process. The results show that CO2can extract the lighter chemical components in the crude oil and make it easier to form miscible phase, which can reduce the viscosity and favorable mobility ratio of oil. What's more, the displacement reduces the impact of gas channeling, which can achieve an enlarged sweeping efficiency to improve filtration ability. In addition, the CO2dissolved in oil and water can greatly reduce the interfacial tension, which can increase the oil displacement efficiency in a large extent. Generally speaking, the recovery rate of residual oil in the micro - model can be elevated up to 15.89% ∼ 16.48% under formation condition by alternate displacement.