随着深水油气田的开发，水下生产系统得到越来越广泛的应用。水下工艺设备处于低温海水环境中，生产关断后受到海水的冷却作用，水下管汇中的原油存在结蜡或凝固的风险。采用湿式保温实现水下管汇流动安全，确保关停时在规定的冷却时间内水下管汇的流体温度高于析蜡点和凝点。应用OLGA软件对水下管汇稳态工况和瞬态工况进行了湿式保温数值模拟，最终计算出水下管汇所需的保温层厚度。

With the development of deep water oil and gas fields, subsea production system (SPS) has played an important role. Subsea process facility is in cold seawater environment. When the SPS is shut down, the oil in subsea manifold is prone to wax or solidify due to the cooling effect of the seawater. The method of wet insulation is adopted to achieve flow assurance of subsea manifold. During the cooldown time, the temperature of fluid shall be higher than the wax precipitation point and condensation point. Thermal analysis of subsea manifold is carried out for both steady state case and transient state case using OLGA software, and the thickness of wet insulating layer is figured out for the subsea manifold.