The project aimed to model and explore the phenomenon of clogging and blockage of pipelines caused by the formation of gas hydrates. Gas hydrates are crystalline compounds where a cage-like water structure surrounds an organic molecule. Under the right conditions, gas hydrates undergo a segregated solidification process that eventually builds up into large regions of solid agglomerate deposits. This phenomenon presents a challenge in the energy sector concerning flow assurance. In fact, this is a serious problem as when this occurs, the blocked section of pipe must be cut out and replaced, resulting in long production stoppages, and high costs associated with repairs and shutdowns of production. In addition, gas hydrates can form in many offshore energy processes, and the unwanted formation of hydrates clogging can produce large negative environmental consequences.
Several software packages have been developed and used by the industry for predicting hydrate formation. These packages, however, are only partially effective since they only focus on the thermodynamics, and omit complex multiphysical phenomena. Traditional multiphysics, however, has difficulties handling phenomena that involve phase transitions and, in general, attempts to account for the formation of solid aggregates within fluids are based on ‘numerical tricks’ aiming at mimicking phase change. At the University of Birmingham a new multiphysics technique, called Discrete Multiphysics (DMP) has been developed to overcome this or equivalent limitations. By employing this new technique, HYDROBLOCK have developed an initial approach to address some of the unresolved challenges in modelling of hydrate blockage and contributed towards new predictive tools that allow to properly explore the gas hydrate formation, growth and blockage.
The preliminary computational tools developed in the project were applied to modelling viscoelastic fluids, an analogous condition to the gas hydrates clogging, and to mimicking the behaviour of substances that might be considered as gels. The computational implementation has already proved to be a practical modelling tool that allows to emulate the flow of substances that exhibit some level of elasticity. Additionally, a computational model focusing on the behaviour of turbulent particle-laden flows was implemented and employed to explore situations where solid particles were transported in similar conditions to those found in the gas pipelines. This set of preliminary computational tools are providing the framework for implementation of a more complete and advanced hydrates clogging analysis tool incorporating the complex and multiphysics character of the phenomenon, and that can be used as a predictive tool by the industry, and as an in-deep analysis methodological groundwork in academia and research.
