(183c) Maintenance and Inspection Methodologies for LNG Liquefaction Plants and Terminals

There are very few records of LNG incidents and accidents and the overall safety records of LNG plants and terminals in general are impressive compared to those of other hydrocarbon process plants such as refineries and petrochemical plants. However, some incidents have occurred recently.

Review of the various root causes over 60 years of plant operation, shows that mechanical failure of equipment and storage tanks, including brittle fracture account for 47.1% of the failures. Corrosion failures related to operation of cold boxes and mercury liquid metal embrittlement, accounted for 17.6%. Overall about 65% of root causes can thus be influenced by maintenance and inspection activities and it is important to optimize these activities to improve the overall plant reliability and availability.

The importance of reliability improvements to make the LNG plants and terminals more competitive and profitable warrants the use of sophisticated technology for inspection and maintenance optimization and systems to ensure the activities are included in the work flow, timely executed and reported. This will become increasingly important as the capacity of the LNG plants and terminals increase. It is recognized that the most effective way to achieve this and to optimize the resource utilization, is by introducing risk based methods for inspection and maintenance strategy development.

This paper will describe how to improve the maintenance and inspection functions to optimize performance and increase profitability of LNG plants and terminals.