Research on Heat Transfer Law of Drilling Fluid Mixed with Low Temperature Phase Change Materials

Abstract

During the drilling process of deep and ultra-deep wells, the hightemperature wellbore environment seriously affects drilling safety and efficiency. Traditional circulating cooling methods are limited by insufficient heat exchange capacity. Therefore, this paper proposes a new active wellbore temperature control technology for drilling fluids based on the endothermic mechanism of ice crystal phase change, and builds a physical simulation experimental system to conduct a study on the influence of multiple parameters. In the experiment, pre-cooled ice crystals were added to the drilling fluid, and the influence of factors such as ice crystal size, concentration, flow rate, initial temperature of the hot fluid, viscosity of the drilling fluid, and initial temperature on the cooling performance was systematically investigated. The results show that increasing the ice crystal size and concentration can significantly improve the heat exchange effect; appropriately increasing the flow rate is beneficial to enhancing heat transfer; the higher the temperature of the hot fluid, the greater the absolute cooling amplitude, but the increase in viscosity and the initial temperature of the drilling fluid weaken the cooling effect. This study provides an experimental basis and technical support for the design and engineering application of ice crystal-type functionalized drilling fluids.OPEN ACCESS Received: 23/12/2025 Accepted: 12/03/2026

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