P4:A COMPREHENSIVE VIEW OF HYDRATES IN FLOW ASSURANCE: PAST, PRESENT, AND FUTURE

Amadeu K. SUM, Carolyn A. KOH, E. Dendy SLOAN
Center for Hydrate Research, Chemical & Biological Engineering Department, Colorado School of Mines, USA 

    Gas hydrates pose the major flow assurance problem in the production and transportation of oil and gas. As production moves to hasher environment (deeper water, longer tiebacks, more produced water), prevention, management, and remediation of hydrates are central for safe and continuous operation. In this contribution, we will provide a comprehensive view of hydrates in flow assurance, in particular, the prevention, management, and remediation strategies that have been developed over several decades at the Center for Hydrate Research at the Colorado School of Mines. We will discuss how hydrate formation conditions are estimated for prevention, how hydrates formation and blockage occurs in flowlines for management, and how hydrate dissociation occurs for remediation. Emphasis will be given to the understanding of hydrate formation and accumulation in multiphase flow, an evolving area that has seen significant advancements over the last several years in terms of fundamental processes for hydrate nucleation, growth, agglomeration, deposition, and plugging. Each of these areas contributes in the development of a comprehensive physical model that incorporates both laboratory and flow loop scale measurements for hydrates. We will overview the processes for hydrate formation and accumulation in oil-dominated, water-dominated, and gas-dominated systems, and the tools developed that can be applied to addressing hydrates in the flow assurance of oil/water/gas flowlines. In particular, emphasis will be given to the mechanistic processes that lead to hydrate growth, hydrate agglomeration, hydrate deposition, and the impact hydrates have on rheological properties and eventual conditions for plugging.