Numerical Simulation and Analysis of a Temperature Field in Subsea Caisson

Subsea oil and gas production systems with caisson are widely utilized in offshore oil and gas resources development. During the development and production processes of oil fields, high-temperature crude oil is transported through jumpers. To assure the continuous flow of crude oil during transportation and to prevent localized high temperatures around the jumper, which could potentially cause a burn risk to divers operating within the caisson, an effective insulation design is essential for the jumper inside the caisson. This study validates experimental models of subsea caissons using numerical simulation of equivalent scale and establishes numerical simulation models of engineering dimensions. The study indicates a high degree of agreement between the temperature field distribution obtained from the numerical simulation and the engineering-scale experimental model. Simulations of the engineering-scale experimental model further demonstrate the significant thermal insulation effect of the insulation layer within the subsea oil and gas production system. It reduces the impact of seawater temperature during normal production and extends the crude oil safety shutdown time during shutdown conditions. Based on considerations of safety shutdown duration and diver safety with respect to seawater temperature, a 60-mm insulation layer is recommended. The research results can provide valuable guidance for insulation design in other subsea caissons in the future.