Discussion on the sweep efficiency of hybrid steam−chemical process in heavy oil reservoirs: An experimental study

作者：Xiaohu Dong, Xiuchao Jiang, Wei Zheng, Huiqing Liu, Renjie Liu, Wuchao Wang, Deshang Zeng, Tai-Chao Wang · 发表于：Petroleum Science · 年份：2022 · DOI：10.1016/j.petsci.2022.06.018 · 被引用次数：28 · 研究领域：Enhanced Oil Recovery Techniques、Petroleum Processing and Analysis、Hydraulic Fracturing and Reservoir Analysis

Non-condensable gas (NCG), foam and surfactant are the three commonly-used additives in hybrid steam−chemical processes for heavy oil reservoirs. Their application can effectively control the steam injection profile and increase the sweep efficiency. In this paper, the methods of microscale visualized experiment and macroscale 3D experiment are applied to systematically evaluate the areal and vertical sweep efficiencies of different hybrid steam−chemical processes. First, a series of static tests are performed to evaluate the effect of different additives on heavy oil properties. Then, by a series of tests on the microscale visualized model, the areal sweep efficiencies of a baseline steam flooding process and different follow-up hybrid EOR processes are obtained from the collected 2D images. Specifically, they include the hybrid steam–N2 process, hybrid steam–N2/foam process, hybrid steam−surfactant process and hybrid steam–N2/foam/surfactant process (N2/foam slug first and steam−surfactant co-injection then). From the results of static tests and visualized micromodels, the pore scale EOR mechanisms and the difference between them can be discussed. For the vertical sweep efficiencies, a macroscale 3D experiment of steam flooding process and a follow-up hybrid EOR process is conducted. Thereafter, combing the macroscale 3D experiment and laboratory-scaled numerical simulation, the vertical and overall sweep efficiencies of different hybrid steam−chemical processes are evaluat...