Analysis on Current Status and Development of Cooling Technology and Equipment for High-temperature Drilling Fluid

With the development of oil and gas drilling in China towards deep and ultra-deep wells, the downhole temperatures continue to rise. This not only affects the performance of drilling fluid but also leads to the failure of critical tools such as measurement while drilling (MWD) and rotary steerable systems. The ground drilling fluid cooling system is essential for addressing the challenges posed by high downhole temperatures and is widely utilized in deep, high-temperature wells both onshore and offshore. The applications of this system both at home and abroad indicate that it can significantly reduce the downhole temperatures, achieving maximum temperature drops of over 20 °C. Consequently, it effectively addresses the issues such as signal loss and service life reduction of downhole tools in high-temperature wells, while enhancing the stability of drilling fluids and wellbore, which significantly reduces non-drilling time. However, the system also encounters challenges, including low cooling efficiency, high power consumption, and inadequate reliability. It is essential to enhance the cooling capacity and field applicability of the equipment by focusing on materials, structure, and technology. In light of the requirements above, it is proposed to develop a high-efficiency, energy-saving cooling system for high-temperature drilling fluid with a large flow rate, utilizing advanced technologies such as compound enhanced heat transfer and low-temperature heat utilization. This provides valuable reference for promoting the development of drilling fluid cooling technology and equipment.