Gas leak shuts down Santos offshore gas field

Santos Ltd. has shut down John Brookes gas field offshore Western Australia following detection of a gas leak from a subsea flange on the main 50 km trunkline to the Varanus Island gas treatment infrastructure.

The leak was discovered during routine work on the normally unmanned John Brookes platform, the company said. Bubbles were seen rising to the sea surface about 20 m from the platform.

Both the pipeline and platform were immediately shut in and depressurized. All personnel were evacuated.

John Brookes field, which lies in production license WA-29-L in the Carnarvon basin, supplies about a quarter of the gas fed into the 390 terajoules/day Varanus Island plant which, after treatment, is then sent to Western Australian mainland’s domestic grid.

The pipeline will remain shut in until the source of the leak has been confirmed and the integrity of the line has been restored, the company said. Repairs are expected to take 4-6 weeks to allow for a return to full production.

John Brookes field was discovered in 1998 in about 100 m water depth and brought on stream in 2005.

Santos is 100% interest holder and operator.