512. 多介质协同水平井注氮+泡沫辅助蒸汽驱开发稠油油藏的实验与数值模拟研究

Experimental Study and Numerical Simulations of Synergistic Effects for Multimedium Horizontal-Well Dissolver United N₂ and Foam-Assisted Steam Flooding in Developing Heavy Oil Reservoirs

针对单一介质在稠油油藏开发中存在功能局限的问题，本文提出了一种多介质协同技术——水平井溶解剂联合氮气与泡沫辅助蒸汽驱（HDNF-SF）。以新疆油田W区块稠油为研究对象，通过一维物理模型实验和CMG-STARS数值模拟，对比分析了热水驱（HWF）、氮气泡沫辅助蒸汽驱（HNF-SF）与HDNF-SF三种方式的开发效果。结果表明，HDNF-SF在提高采收率、降低含水率、延长压力稳定期等方面表现最优，采收率最高达43.5%，油汽比达0.35。该技术通过溶解剂降黏、氮气保温与能量补充、泡沫调剖等多重机制协同作用，有效抑制汽窜、扩大波及体积，显著提升稠油开发效果。

CMG软件应用情况：

本研究采用CMG-STARS数值模拟软件建立三维模型，模拟了不同注入方式（HWF、HNF-SF、HDNF-SF）下的油藏动态。模型设置了5个组分（水、表面活性剂、油、溶解剂C6H14、氮气），并基于实验参数设定渗透率、温度、注入速率等条件。模拟结果与一维物理实验高度吻合，验证了模型的可靠性，并进一步揭示了HDNF-SF在多场耦合条件下的优势。

研究结论：

1. 一维实验表明，HDNF-SF技术具有最优的驱油效率和最低含水率，采收率达44.6%，显著优于HWF和HNF-SF。
2. CMG数值模拟结果验证HDNF-SF在长期开发中采收率持续上升，最终达43.5%，油汽比最高为0.34，累计产油量达43200 m³，优于其他方法。
3. HDNF-SF通过溶解剂降黏、氮气补充能量与保温、泡沫调剖堵窜，三者协同作用显著改善了蒸汽驱的波及效率和热利用率。
4. 敏感性分析表明，氮气与泡沫的注入比例和油藏温度是影响采收率的关键因素。
5. HDNF-SF在实际应用中具备更强的经济性和操作可行性，尤其适用于稠油油藏中后期开发。

作者单位：

中国地质大学（北京）能源学院

Abstract

The application of single-medium fluids is relatively ineffective due to their limited functionality in heavy oil reservoirs. To compensate for the limitations of single-medium fluid injection, multimedium collaborative technologies have been proposed and have become a primary focus of research. In this paper, a series of experiments were designed and conducted on multimedium-assisted steam flooding in horizontal wells based on the heavy oil samples from the W block in Xinjiang Oil fields, China. Production, pressure, and produced fluid characteristics were studied. Results indicated that the united N₂ and foam-assisted steam flooding demonstrated the highest oil displacement efficiency and the lowest water cut in the horizontal well, at 44.6 and 88.2%, respectively. The horizontal-well dissolver united N₂ and foam-assisted steam flooding (HDNF-SF) exhibited the longest pressure stabilization period with a higher oil content in the produced fluid. Extended numerical simulations corroborated the effectiveness of HDNF-SF in heavy oil reservoirs to explore multimedium collaborative mechanisms. The HDNF-SF achieved the highest oil recovery and oil-to-steam ratio, at 43.5% and 0.35, respectively. In HDNF-SF, N₂ facilitates energy replenishment and thermal insulation; the dissolver reduces crude oil viscosity, and the foam aids in profile control by providing plugging functionality. Through the synergistic effects of these substances, HDNF-SF can prevent steam channeling, improve the displacement efficiency, enhance sweep efficiency, and ultimately increase oil recovery. These findings hold significant theoretical and practical implications for improving sweep efficiency in heavy oil reservoirs.