As oil and gas exploration extends toward deep and ultra-deep formations, downhole measurement-while-drilling (MWD) instruments are subjected to increasingly severe high-temperature environments, making efficient thermal management essential for stable operation. This study presents the engineering design of a thermal management system for downhole MWD instruments. Thermal insulation material selection, heat dissipation structure design, and numerical simulation are combined to develop a system suitable for high-temperature downhole conditions. A comparative evaluation of asbestos and aerogel particle insulation demonstrates that the insulation temperature difference increases with aerogel thickness, indicating a strong dependence of thermal insulation performance on material thickness. The thickness of the drill collar structure is also shown to influence overall insulation effectiveness. Considering the heat generation of the Raman instrument and external heat conduction, a heat dissipation structure integrating three-stage thermoelectric cooler (TEC) active cooling with copper fin-enhanced convective heat transfer is proposed. Key geometric parameters of the copper fins are determined based on TEC cooling capacity and structural strength requirements. A three-dimensional thermal model including the heat sink plate and drill collar is established and analyzed using ANSYS Fluent. Simulation results indicate that the tool housing temperature approaches the drilling fluid temperature after TEC cooling and fin-assisted heat dissipation. Heat flux analysis confirms efficient heat transfer along the “TEC-copper fins-drilling fluid” pathway. The proposed synergistic thermal management design provides effective engineering support for downhole MWD instruments operating in high-temperature environments.
Wang et al. (Fri,) studied this question.