Modelling and Optimization of Compact Sub-sea Separators - Gas-Liquid separation

Abstract

This Master thesis focuses on Modelling and Optimization of Compact sub-sea separators using a given separation system. The separation system consists of three separation units: a gravity separator, a deliquidizer and a degasser.

The steady state models developed have been aimed at predicting phase separation in the separator units. The models in addition predict stream outlet phase fractions and flow rates based on known inlet conditions and separator geometry.

Model simulations have been performed in Matlab and results have shown trends that are consistent with theoretical expectations. They have in some cases for the deliquidizer been compared to experimental data and close agreement has been observed. However, in other cases, validation of simulation results has not been possible due to lack of experimental data but the results are thought to be theoretically reasonable.

Optimization on the system has been carried out aimed at maximizing the phase fractions of the streams to the compressor and pump respectively. Results have shown an average of less than 5 % of dispersed phase in a continuous phase in exit streams.

Keywords: Modelling and Optimization, Compact sub-sea separators, steady state models, gas/liquid separation.