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.