School of Earth and Space Science, Peking University, Beijing, China.
Institute of Oil & Gas, Peking University, Beijing, China.
PLoS One. 2018 Jun 22;13(6):e0199709. doi: 10.1371/journal.pone.0199709. eCollection 2018.
There are many heavy oil reservoirs in offshore oilfields in China. Steam and multiple thermal fluid stimulation technologies are of increasing interest and have been applied to an increasing number of projects. During the stimulation or displacement of heavy oil reservoirs during thermal recovery, several factors, such as reservoir heterogeneity, are prone to cause channeling phenomena and affect the thermal recovery effect of steam stimulation. According to the unique requirements for the stimulation of multiple thermal fluids for offshore heavy oil, this study used transmission, blocking and relieving, heat resistance and a comprehensive evaluation of parallel sand tube experiments to conduct a screening evaluation of plugging systems for the stimulation of multiple thermal fluids, screen out a commonly used plugging agent in the current stage and propose corresponding guidance for the selection basis. The results show that foam, gel, foam gel and temperature-sensitive gel systems have a good transmission performance, whereas the oil sludge exhibits a poorer performance. The phenolic resin system exhibits great plugging properties, followed by oily sludge, temperature-sensitive gel, gel, foam gel and foam. Considering about washing resistance properties, phenolic resin system shows the best quality, followed by oily sludge and temperature-sensitive gel. The oily sludge system brings the best performance in plugging a high-permeability channel than phenolic resin gel and temperature-sensitive gel.
中国海上油田有许多稠油油藏。蒸汽和多种热流体激发技术越来越受到关注，并已应用于越来越多的项目中。在稠油油藏热采过程中的激发或驱替过程中，储层非均质性等因素容易导致窜流现象，影响蒸汽激发的热采效果。针对海上稠油多种热流体激发的特殊要求，本文采用传输、封堵和缓解、耐热性以及平行砂管实验综合评价等方法，对多种热流体激发的封堵体系进行了筛选评价，筛选出了现阶段常用的封堵剂，并提出了相应的选择依据。结果表明，泡沫、凝胶、泡沫凝胶和温敏凝胶体系具有良好的传输性能，而油泥则表现较差。酚醛树脂体系表现出很好的封堵性能，其次是油泥、温敏凝胶、凝胶、泡沫凝胶和泡沫。考虑到耐洗性，酚醛树脂体系的质量最好，其次是油泥和温敏凝胶。油泥体系在封堵高渗透通道方面的性能优于酚醛树脂凝胶和温敏凝胶。
