An experimental study of the hydrate blockage in the oil-dominated flow system

This paper aims to deal with the plugging of natural gas hydrate in the high-pressure oil-gas mixed transmission lines. Therefore, an experimental study was conducted of oil-dominated flow in the Chinese first set of high-pressure natural gas hydrate experimental loop which was newly built by China University of Petroleum in Beijing. In this experiment, we explored the impacts of pressure, flow rate, etc. on the natural gas hydrate slurry flow, plugging tendency, and the plugging time. And a real-time online particle size analyzer was employed to monitor the variation tendency of hydrate particle diameters during the process of hydrate slurry generated within the system. The following findings were obtained. (1) Higher pressure will quicken the plugging, which increases the risk of hydrate plugging. (2) Increasing the flow rate can slow down the tendency of hydrate plugging to reduce the probability of hydrate blockage; But, there was a phenomenon called the critical minimum safety flow rate, that is, if the flow rate is greater than a certain value, hydrate plugging will not occur, and the fluid flows in the loop in the form of slurry, otherwise, hydrate blockage will occur. The agglomeration of particles during the hydrate formation process is the main reason for hydrate slurry blockage. ©, 2014, Natural Gas Industry Journal Agency. All right reserved.