The Perth Basin, a north-south trending province extending about 1,300 km along the southwestern margin of Australia, was, prior to 2014, perhaps dismissed for large scale future success that it sees today. Since the first discovery nearly 60 years ago, the basin, although productive, has often been overshadowed by its noisy northern neighbour, the prolific North Carnarvon Basin. However, since the world class Waitsia discovery in 2014, that looks set to change.

The Waitsia gas discovery represents a common theme recently seen within the basin, where operators have had success within deeper stratigraphy, often below previously drilled structures. The Waitsia discovery came about from AWE deepening the Senecio 3 well, which was originally appraising the Senecio field, to test secondary targets. The result was discovering gas pay within the Permian Kingia and High Cliff sandstones and opening up the now prolific Kingia structural play, where other operators have also had subsequent big success. Waitsia, which at the time of discovery was the largest conventional onshore find for over 40 years in Australia, has gone on to be developed and is currently producing and undergoing its next stage of development (Beach Energy operated).

The Kingia and High Cliff sandstones’ deposition is associated with the first of three extensional periods within the geological evolution of the Perth Basin. This first episode of rifting during the Early to Middle Permian resulted in the formation of northwest to north-northwest half-grabens, where the High Cliff Sandstone and Kingia Sandstone reservoirs were deposited. As mentioned, recent exploration has targeted these plays with great success predominantly in the Kingia, leading to the resurgence of exploration and development activities in the basin. This presentation will look to further assess these drilling results, provide Kingia play analysis and assess prospectivity, where interestingly such high standard reservoirs are found at depths where reservoir quality would be expected to be reduced.

With more and more success from the Kingia play and development plans being outlined, gas discovered will require a buyer in a market which is more interesting than others. Western Australia state policy currently prevents gas export overseas or to eastern states meaning operators must find domestic state buyers. At Waitsia Stage 2 however, gas has been given a pass on the export ban, with it to be sent to the North West Shelf LNG Project’s Karratha Gas Plant for liquefaction and export from 2H 2023 to 2028. In Western Australia there is a predicted supply gap from 2025, which Perth Basin gas will tap into, but the Waitsia arrangement could show a sign of things to come if there are further delays to the LNG developments on the North West Shelf. At this stage other operators are looking domestically, with Strike Energy’s major South Erregulla discovery in the Kingia outlined to supply Project Haber, a proposed fertiliser project, which supports Strike’s net zero ambitions. With this in mind, as well as analysing the successful geology, the presentation will provide a closer look at the commercial environment, and what other net zero based/carbon capture utilisation and storage (CCUS) projects are being proposed for the basin as the world focusses on the energy transition.