Equipment failures, malfunction of protection devices, human errors, process upsets, etc. are the common causes for unplanned shutdowns. These unplanned trip events can lead to substantial production opportunity losses and impact company's profit. The requirements of outstanding performance forces companies to take effective measures in reducing plant downtime frequency and its consequential costs.
ADGAS operates three LNG trains and five gas treating plants on a remote Island. Due to its harsh operating environment, equipment aging, frequent change of feed gas conditions, etc., maintaining a reliable and stable operation has been very challenging. Since 1997 the accumulated production losses caused by unplanned shutdowns has reached few hundred million dollars. Among these losses, unplanned trips due to instrument and control failures have contributed to more than 20% of total production losses. Theses failures also resulted in increased flaring. Thus minimizing unscheduled plant downtime and improving the reliability of instrument devices is imperative both economically and environmentally.
This paper describes a three-track approach which implementation has led to 66% reduction on the number of unplanned trips caused by instrument failures.