Institute of Petroleum Engineering

Centre for Gas Hydrate Research Publications



Abstract 156

HYDRAFLOW: A Novel Approach in Addressing Flow Assurance Problems

Azarinezhad, R., Chapoy, A., Anderson, R., Tohidi, B.
6th International Conference on Gas Hydrates, Vancouver, Canada, July 6-10 (2008)

Global oil and gas production is increasingly being dominated by exploitation of deepwater reservoirs and mature fields. Consequently, new technologies have to be developed to cope with long tiebacks and high water-cuts. A main challenge for these production systems, which are associated with higher pressures and lower temperatures, is hydrate problems. Uncontrolled formation of hydrates may results in plugging of transport pipeline. The current methods for avoiding hydrate blockages are based on prevention/delaying solid formation by injecting thermodynamic or kinetic inhibitors and/or operation outside the hydrate stability zone (e.g. by insulation and/or heating). However, the above techniques are less economical and/or practical for deepwater operation and long tiebacks. The HYDRAFLOW concept, as explained in this paper, is a patented ‘Cold Flow’ assurance technology which aims to address this problem by breaking the tradition of preventing solids formation. In HYDRAFLOW, hydrate crystals in pipeline are actively encouraged, but prevented from agglomeration (using anti-agglomerants if necessary), eliminating the need for expensive thermal/chemical inhibition strategies, whilst improving the practicalities of multiphase transport, including slugging. The objective is to minimise/eliminate the gas phase by converting most of it into hydrates in the presence of excess water. It is also proposed that the technology could involve a “Loop Concept”, wherein the liquid phase plays the role of carrier fluid, collecting produced fluids from various wells and delivering them to the production unit before being recycled. This paper presents the latest results of development of the HYDAFLOW technology and mainly focuses on the potential for recycling either whole or part of the anti-agglomerants (AAs) in the context of the ‘Loop’ concept. For this purpose, the distribution of AA components between different phases including oil, free water and hydrate were measured and also the performance of the residual AA in the free water phase and of its components absorbed in the oil and/or hydrate phase were assessed.

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