Prevention and Removal of Gas Hydrates in Pipelines Using Ultrasonic Waves

Gas hydrates are representatives of a class of compounds known as clathrates or inclusion compounds. Natural gas and crude oil normally reside in reservoir in contact with water. Water can combine with low-molecular weight natural gases to form a solid, hydrate, even if the temperature is above water freezing point. Hydrates are considered as nuisance because they block transmission lines, cause tubing and casing collapses, and foul process heat exchangers, valves and expanders. Fundamentally there are different ways to prevent hydrates from forming. In this study application of ultrasonic waves to prevent hydrate formation and instantaneous remove formed hydrate in gas pipelines ultrasonic waves was investigated. Piezoelectric transducers with frequency of 38 kHz and 1.7 MHz have been used. Results show ultrasonic waves with low frequency cause the crystals to disintegrate and melt into the liquid and high frequency changes water into cold vapor directly, which can exit with main gas stream.