海上稠油热采平台具有空间小、注汽温度高、注汽压力高等特点，温度高达300 ℃，一旦高温高压蒸汽发生泄漏将导致严重后果，对设备及巡检人员造成巨大威胁，亟需一种有效的蒸汽泄漏监测方法。为解决该问题，综合考虑热力学、流体力学等因素影响，研究了海上稠油热采蒸汽泄漏监测机理，提出了基于机理与推理相结合的虚拟传感监测方法，首次将蒸汽泄漏间接测量方法应用到海上稠油热采蒸汽泄漏监测，搭建了蒸汽泄漏监测模型，形成了适用于海上稠油热采蒸汽泄漏监测的混合传感技术，进行蒸汽泄漏实时在线监测。结果表明：该方法可以实现基于运行数据的泄漏判别、泄漏量估计，对蒸汽泄漏失效状态在线直接表征，能监测的泄漏率最小可达到0.5%，泄漏判别准确率在96.49%以上，与传统方法相比，能监测的最小泄漏率提升了90%，泄漏判别率至少提升了1.6%。该方法解决了现场物理传感器安装受限多、有效的监测数据难以获取且准确性受限于人员经验的问题，弥补了热采平台现场监测手段的不足，为海上稠油开发提供安全保障。

The offshore heavy oil thermal recovery platform has the characteristics of small space, high steam injection temperature, and high steam injection pressure, with temperatures up to 300 ℃. Once high-temperature and high-pressure steam leaks, it will cause serious consequences and pose a huge threat to equipment and inspection personnel. An effective steam leakage monitoring method was urgently needed. In order to solve these problems, the influence of thermodynamics, fluid mechanics and other factors were considered comprehensively to study the mechanism of steam leakage monitoring in offshore heavy oil thermal recovery. A virtual sensing monitoring method based on mechanism and inference was proposed, and for the first time, the indirect measurement method of steam leakage was applied to steam leakage monitoring in offshore heavy oil thermal recovery. A steam leakage monitoring model was built, and a hybrid sensing technology suitable for steam leakage monitoring in offshore heavy oil thermal recovery was formed for real-time online monitoring of steam leakage. The results show that this method can achieve leak discrimination and leak estimation based on operational data, and directly characterize the failure state of steam leaks online. The minimum detectable leak rate can reach 0.5%, and the accuracy of leak discrimination is above 96.49%. Compared with traditional methods, the minimum detectable leakage rate has increased by 90%, and the leakage discrimination rate has increased by at least 1.6%. This method solves the problems of limited installation of physical sensors on site, difficulty in obtaining effective monitoring data, and limited accuracy due to personnel experience, making up for the shortcomings of on-site monitoring methods for thermal recovery platforms and providing safety guarantees for offshore heavy oil development.