Gas turbines and their associated package equipment can be expensive machines to remove, replace and install. The budget necessary to achieve the purchase of replacement equipment, undertake the corresponding logistic exercise and incur subsequent disturbance to an installation or process plant will be significant, particularly in difficult to access locations.
It is quite feasible that for installations having a finite future utility life, or end of field life production constraints, full replacement of an ageing turbine machine is something that may not be economically advantageous. For such commercially unjustifiable occasions, refurbishment and enhancement of an existing operational mature machine can prove to be the more cost-effective solution. Such refurbishment and recovery activities bypass the need for enormous removal work scopes, heavy mechanical handling and civils works associated with full replacement, a reduced budget may be channelled toward recovering the integrity and performance of an existing subject machine. We include a worked example of such a life extension project undertaken by Gas Turbine Resources on behalf of Shell Petroleum. Due to a previous engine failure the subject machine had not operated for ten years prior to the recovery activity commencing and in addition during that very long downtime time period, many of the system devices had been scavenged to support other machines.
During 2011 GTR undertook a full renovation of the subject engine including installation of a replacement core engine and gearbox, rectification of all package fluid and control systems, general repair, alternator intervention and reinstatement, followed by recommissioning of the turbine itself. The result... for the last 8 years post intervention the subject machine has again become a prime contributor to the local power plant capacity.