Distributed thermal management system for downhole electronics at high temperature

Abstract

The logging tools, which are widely utilized to detect the underground petroleum resources, are usually exposed to the high-temperature environment. Conventional thermal management system (CTMS) generally utilizes the vacuum flask for high-temperature insulation and phase change materials (PCMs) for centralized heat storage. As the heat sources increase and the skeleton becomes longer, the thermal performance of CTMS declines due to the increasing thermal resistance between heat sources and PCMs. To tackle this issue, a distributed thermal management system (DTMS) is proposed for the long-skeleton and multi-heat-source logging tools by arranging PCMs dispersedly in the skeleton. Numerical simulations are conducted to compare the performance of DTMS and CTMS. It is showed that the maximum temperature of DTMS decreases by 68 °C compared with CTMS, and the heat storage of PCMs in DTMS is 3.5 times higher than that in CTMS. Furthermore, the simulation results are validated by experimentally investigating the thermal performance of the logging tool with DTMS, and good agreement between the simulation and experiment is reached with the maximum relative error lower than 10%. DTMS is more practical for the realistic logging tools than CTMS, which may contribute to the development of the oil and gas detection in deeper and hotter wells.