Durable and reliable thermal management system with superior temperature uniformity for sidewall coring tool in extreme thermal environments

Abstract

The sidewall coring tool (SCT) plays a crucial role in exploring the distribution of oil and gas resources, which needs to operate in a challenging high temperature (205 °C) and vibrating downhole environment for 21 h. However, the internal electronics are unable to withstand such extreme temperatures. Previous investigations on thermal management of downhole electronics have failed to ensure long operational duration and reliability. To solve this issue, a durable and reliable thermal management system (TMS) with superior temperature uniformity was proposed for the SCT in this paper. First, the proposed system adopted heat storage modules (HSMs) with high heat storage density and heat diffusion coefficient to enhance the heat storage rate and extend the operational duration. Second, HSMs were utilized for storing heat from nearby heat sources to improve temperature uniformity. Meanwhile, the reliability of HSMs was verified by high-temperature vibration experimental tests. Finally, through iterative optimization, the system utilized a well-designed configuration of thermal insulators and HSMs to further improve temperature uniformity, thereby extending the operational duration of the system. The performance of the total system was evaluated by thermal simulations. The maximum temperature of the heat sources remained below 150 °C after 21 h, with a maximum temperature difference between any two sources not exceeding 12 °C. Furthermore, the experiment was conducted to validate the simulated results, with the relative error within 5 %. The proposed TMS demonstrates a significantly extended operational duration and improved reliability compared to previous works, which has been successfully applied to downhole operations.