KEEPING IT GOING—LONGFORD COMBINAIRE REFURBISHMENT

Abstract

ExxonMobil Australia Pty Ltd’s subsidiary, Esso Australia Resources Pty Ltd (ExxonMobil), is undertaking a refurbishment program on the critical combinaire cooling units at its Longford Gas Plant 1. The combinaires are combination air-cooled heat exchangers with evaporative cooling supported on a large concrete structure. The functions performed include gas treating, inlet gas cooling, distillation reflux and condensate cooling.

The Longford combinaire units have already been in operation in excess of 30 years and the facility will be required to operate for many more years, given the significant reserves remaining in Gippsland. The combinaire units provide the central cooling duties in both the Longford crude stabilisation plant and Gas Plant 1. Shutdown of these units has a major impact on the plant processing capacity for both oil and gas. An in-depth understanding of forecast market demand, processing requirements and interaction of the process units throughout the Longford facility has enabled the identification of discrete annual periods when certain sections of the combinaire unit can be brought offline.

The refurbishment campaign was developed to systematically refurbish sections of the combinaire unit that were not at full capacity seasonally. Critical to achieving the tight timelines is having timely delivery of refurbished and new components to site. This is being achieved through close collaboration with numerous vendors and initiatives such as setting up a local workshop for tube bundle refurbishment.

The combinaire refurbishment campaign is on track to meet the target completion date and continues with minimal impact on Bass Strait production of oil and gas. Success is being achieved through detailed analysis across a range of disciplines and the application of a design-one, build-multiple philosophy. A large and complex project being undertaken whilst keeping the plant going.