Flow Assurance of Hydrate Risk in Natural Gas/Oil Transportation: State-of-the-Art and Future Challenges

Abstract

Deepwater oil and gas development is extremely difficult and challenging. One of the most critical challenges stems from hydrate deposition, aggregation, and the eventual blocking of the deepwater oil and gas transportation system. The low-temperature and high-pressure environment in the deepwater oil and gas field causes the combination of gas molecules and water molecules to form hydrate, thus affects the hydrocarbon transportation. In this Perspective, to discuss the commonly faced safety issues for deepwater oil, gas, and gas hydrate development, the following three critical problems are comprehensively summarized and analyzed. First, the mechanisms of phase transition, aggregation, and blockage of the hydrate in the multiphase transport system have been investigated from the microscopic perspective to macroscopic characteristics. Second, based on different theoretical models, the algorithms are discussed to introduce an online monitoring technique for hydrate blockage, which can detect the safety risks and provide early warnings. Furthermore, for hydrate blockage prevention and control, the active methods based on chemical injection and the passive methods based on the modification of physicochemical properties of pipeline surfaces are reviewed. Finally, an outlook is provided for the future development of deepwater oil and gas and for the schemes to mitigate hydrate blockage.