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Gas hydrate blockage is a longstanding problem in the oil and gas industry, responsible for the interruption of hydrocarbon flow, posing economic and safety risks. Computational modeling methods are required to estimate the dissociation pressure of the original system and its shifting in the presence of thermodynamic inhibitors so as to avoid excessive inhibitors dosages, high operating costs and serious environmental impacts. On the other hand, the properties and characteristics of clathrate hydrates have paved the way to new technological solutions such as energy storage, gas separation, carbon capture and desalination, which also require accurate estimates of hydrate stability conditions. Various commercial PVT software packages serve as established computational tools to model hydrate phase equilibria and predict dissociation conditions. Those products exhibit major differences in the underlying computations such as the hydrate modeling framework, the EoS models used to calculate components fugacity in fluid phases, the thermodynamic approaches in the presence of salts and inhibitors, and the phase models of potential hydrate solid coexisting phases (e.g., ice). Additionally, the fitted parameters of the utilized computational models (i.e., the Kihara potentials) are set differently by each developer, depending on the experimental data used to tune their models.In this work, the performance of some of the industry-standard commercial software packages is evaluated. The evaluation is performed by using several systems, varying from single-component ones to highly inhibited ones. The comparative evaluation is based on a large database of 400 experimental dissociation pressure data points which has been published over the last 5 years. The results of this work provide valuable insights for industry professionals and academics interested in obtaining accurate predictions of hydrate dissociation conditions. It is shown that each package exhibits its own performance profile with individual strengths and weaknesses in calculating hydrate dissociation conditions of different gas mixture systems. The evaluation is supplemented with the detailed description of the modeling principles, thermodynamics, and algorithms used by each developer. |
