Natural gas production from Bass Strait and the Longford Gas Plants commenced in 1969, and in 2024, operations continued to supply approximately 40% of Eastern Australia’s domestic gas demand. As part of a major asset streamlining process undertaken in late 2024 due to declining reserves, all onshore and offshore facilities and pipelines supporting oil production and redundant gas processing capacity were shut-in for production purposes, leaving six gas platforms and two subsea tiebacks – connected via an extensive pipeline network – online. The streamlining process has delivered greater operational flexibility and business advantages; however, it has also introduced several interconnected engineering challenges, including issues related to gas pipeline flow assurance, and the operability of the asset’s two main multi-phase trunklines: the SNA600 and the MLA500. This extended abstract focuses on what has been learnt while addressing two of these challenges: liquid slugging caused by increased volumes of liquid held up in the SNA600 and MLA500 trunklines, and the reliability of the basin’s closed-loop glycol supply system. The Longford Gas Plant and the producing platforms in Bass Strait are owned by ExxonMobil (50%) and Woodside (50%) and are operated by ExxonMobil.
Burgin et al. (Wed,) studied this question.