Operational Mode Monitoring of Gas Turbines in an Offshore Gas-Gathering Application

A computer-assisted monitoring system has been implemented on GT-61 Gas Turbines employed in offshore gas gathering. Operating load data are continuously recorded at the site and evaluated at the turbine manufacturer’s plant on a mainframe computer, where existing analysis and testing techniques are utilized to predict the service fatigue lives of the power turbine structural components. The data acquisition hardware, the data reduction software, and the life prediction techniques are each described. The data collected indicate that offshore gas gathering equipment will experience many more operating load cycles than comparable equipment in pipeline service. The fatigue life predictions reaffirm the suitability of the GT-61 for this more severe service.