Terje Sontvedt

Erosion of oil&gas industry choke valves using computational fluid dynamics and experiment

As part of several years research activity with erosion in chokes, Norsk Hydro ASA has developed a model to estimate erosion and lifetime of chokes by incorporating erosion models into particulate flow models. This model has been verified with the results from flow and erosion testing of two different types of chokes, Needle&Seat and External Sleeve. The erosion tests with both the modified Needle&Seat choke and the External Sleeve choke gave peak erosion rates only two or three times larger than calculated. This is assumed to be near the uncertainty of the erosion model alone. This is very satisfactory for such complex flow geometries. The model and the experiments demonstrated that the External Sleeve choke is much more prone to erosion attack, at the given low pressure conditions.