Transient Calculation Studies of Liquid–Solid Collision in Jet Descaling

Sichuan is gradually being transformed and is utilizing groundwater and thermal resources. However, this investigation found that the high mineralization rate of geothermal resources in the Sichuan Basin is common and efficient, and environmentally friendly descaling technology is the key to promoting the utilization of thermal resources in low-yield oil and gas wells. Due to the high efficiency, low cost, and lack of pollution of high-pressure jet descaling, it has attracted more and more attention recently, but the mechanism of jet descaling is still unclear. The key to jet descaling is the stress concentration in the scale caused by the impact of droplets from the jet. In this paper, the process of jet descaling is simplified as a 2D droplet–scale collision with a detailed theoretical analysis of the stress on the scale. A circular droplet was simulated to impact the surface of the scale. By using numerical methods for transient calculations, we couple the pressure of the droplets and the scale strain. We acquired transient equivalent stress fields inside scales and pressure distributions inside the water droplet. As a result of the impact, areas of high stress in the scale appeared. Due to the stress superposition, the highest stress is concentrated in two areas: the contact edge and the shaft. These results can identify the mechanism for high-pressure jet descaling and help improve the efficiency of high-pressure water-jet descaling.