(70b) A Probabilistic Method for Quantifying Risk in Hydrate Forming Systems | AIChE

(70b) A Probabilistic Method for Quantifying Risk in Hydrate Forming Systems


Norris, B. W. E. - Presenter, University of Western Australia
Johns, M. L., University of Western Australia
May, E. F., University of Western Australia
Aman, Z. M., University of Western Australia
As the development of oil and gas resources moves toward the deep water, the consequence of hydrate blockage increases. Risk avoidance by operating outside the stability region, or shifting the equilibrium curve using thermodynamic inhibitors, has been the dominant practise traditionally. More recently, economic pressures have led to a paradigm shift toward risk management strategies, where limited operation within the stability region is managed to prevent plug formation. To confidently employ these methods, predictive tools that incorporate the effect of hydrate formation on multiphase transportability and flowability of the system are required. Such tools allow for a deterministic calculation to assess the severity of hydrate formation for a given condition set. However, some properties, such as the hydrate nucleation temperature, are inherently stochastic, and others, such as the flowing bottomhole pressure, will inevitably fluctuate as the field is produced. Instead of choosing a representative value for these properties to perform a small number of deterministic calculations, this work presents an algorithm to explore the parameter space more broadly, by coupling a Monte-Carlo engine to a rapid steady-state flow framework. This permits flow assurance engineers to explore the sensitivity of their system to (i) hydrate formation, (ii) evolving field conditions and (iii) operating methods.