Opus has successfully concluded a specialised sloshing analysis project, which posed a number of unique challenges.

The contract – carried out for a major oil company – tasked Opus with carrying out a 3D multi-phase CFD (computational fluid dynamics) analysis of a two phase oil from water separator, onboard a floating platform in the Gulf of Mexico.

Typically, previous CFD analyses of sloshing in separators caused by motion have determined that the period of motion of any separator is at least double the natural sloshing frequency of the fluids within the unit.

However, this project found that the period of motion of the separator was close to the natural sloshing frequency of the fluids within the separator, resulting in unfavourable fluids behaviour, which were detrimental to the performance and the structural integrity of the vessel internals.

As a result of these critical findings, Opus was required to vigorously validate the results to ensure they were accurate.

This involved creating a 2D simplified model of the separator and modelling it at different motion periods to assess the effect these had upon the behaviour of the fluids, resulting in Opus providing the client with detailed information on how the behaviour would impact on the performance of the vessel internals, and making suitably effective recommendations.

The project was the first to be completed under a recently secured strategic partnership agreement between the company and engineering simulation technology and solutions provider, CD-adapco, which sees Opus utilise CD-adapco’s CFD software, Star-CCM+, on client projects, as well as its own research and development work.

With a collaboration agreement in place, a key element of the partnership sees Opus and CD-adapco carry out joint projects, and also exchange and transfer knowledge and technology.

Nigel Weir, managing director of Opus, commented: “This project threw up unique challenges in validating that the behavior predicted by the 3D CFD analysis was a true representation of what would happen within the actual vessel.

“Both Opus and CD-adapco worked exceptionally well together to achieve the objectives of the study. The Opus test facilities, where we also analyse separators by physical modelling on a motion test rig, have also provides important validation input to these type applications.”

Opus provides the offshore oil and gas market with a range of engineering and environmental services, including fluids characterisation and performance monitoring of offshore facilities, validation testing of process equipment and marine ecotoxicity testing of production chemicals.

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