Equinor releases Great Australian Bight drilling plan

Feb. 19, 2019
The Australian arm of Norwegian international energy company Equinor has released for public comment its draft environment plan for the proposed drilling program of the Stromlo-1 wildcat in exploration permit EPP39 in the South Australian portion of the Great Australian Bight.

The Australian arm of Norwegian international energy company Equinor has released for public comment its draft environment plan for the proposed drilling program of the Stromlo-1 wildcat in exploration permit EPP39 in the South Australian portion of the Great Australian Bight.

The 1,500-page plan details planned activity for the controversial well, including all the measures to be put in place to avoid and mitigate impacts on the environment of the Bight.

It is the first time a draft EP for an offshore exploration well has been published prior to submission and assessment by Australia’s National Offshore Petroleum Safety and Environmental Management Authority (NOPSEMA).

Equinor said it had engaged with more than 100 separate organisations in South Australia during the past 2 years and has now opened the plans for public comment for a period of 30 days. Comments are to be submitted directly to NOPSEMA.

The document outlines the existing environment in the Bight and describes all relevant risks, however unlikely. Jone Strangeland, Equinor country manager for Australia, said that by identifying every possible risk, the company can better prepare for safe operations.

The proposed Stromlo-1 is to be drilled in the Ceduna subbasin 730 km west of Adelaide, 372 km offshore, and 476 km west of Port Lincoln.

The closest existing well is Gnarlyknots-1/1A, 98 km northeast, drilled in 2003 by Woodside Petroleum Ltd. (OGJ Online, Apr. 23, 2003).

Stromlo-1 will be drilled in 2,240 m of water through 2,700 m of sediments to a proposed total depth from the rig floor of 5,186 m.

Data will be acquired through mud logs and logging-while-drilling techniques. Other logging programs will be instigated if warranted once the well reaches TD.

A dynamic positioning drilling rig, yet to be named, will be supported by three service vessels and two helicopters, the latter based at Ceduna airport. The well is slated to be spudded during the southern hemisphere’s summer of 2020-21.

EPP 39—and neighbouring permit EPP 40—were originally held by BP Australia (OGJ Online, Feb. 24, 2015). Equinor farmed in for 30% interest in 2013 and then took up a 100% interest in both permits in June 2017 when BP withdrew from the area completely.

There have been only 13 exploration wells previously drilled in the Bight, beginning with Shell Australia’s Echidna-1 and Platypus-1 in 1972 and ending with Woodside’s Gnarlyknots program in 2003. None have found commercial hydrocarbons, but there have been favorable indications of a petroleum system in the region, particularly in deep waters.

Antidrilling groups have been vocal in their opposition to petroleum exploration, citing the pristine environment, including the documented presence of whales passing through the area and numerous benthonic flora and fauna.

Equinor says it has covered all aspects in its environment plan and that it will take all public comments into consideration before updating the document and officially submitting it to NOPSEMA.