Strike Energy as operator of the EP469/L25 Joint Venture, which includes the West Erregulla gas field, has announced multiple successful gas discoveries in the Erregulla Deep-1 (ED-1) well in EP469.

The ED-1 well was drilled to a total depth of 5,225m MD or 4,944m TVDSS making it the deepest well ever drilled onshore Australia.

The ED-1 well has made two high-quality, low impurity conventional gas discoveries. Both discoveries are observed to be blocky zones of good quality gas charged sandstone reservoir.

Net gas pay and porosities have been interpreted from Mud Logs, Logging Whilst Drilling (LWD) data and Wireline Logs. Pressures and gas samples across both formations were taken which confirmed permeability and gas gradients. Gas samples secured from the discoveries were analysed in the laboratory for their composition and makeup. Independent assurance was undertaken in the compilation of this petrophysical assessment with the cutoffs used as those for the West Erregulla wells and a range of salinity assumptions used to screen the results. These initial results and outcomes will be further confirmed through flow testing, which is scheduled to commence later this month.

Petrophysical evaluation was also conducted over a sand body within the Irwin River Coal Measures. This zone had a strong mud gas response and was measured to be substantially overpressured. Unfortunately, due to bore hole breakout in this zone, a sample was unable to be collected and cannot be categorised as a discovery at this time. This zone warrants additional evaluation given the existing data collected.

Strike will now run the production liner and cement in place before completing the well for production testing. The rig is expected to demobilise in the coming fortnight and Strike is preparing to immediately follow with the mobilisation of a well test spread. 

Implications of Erregulla Deep results for Strike and the extension of the Permian Gas Play

The Erregulla Deep-1 well is the most easterly penetration of the Permian gas play. Strike has a commanding acreage position across its 100% owned tenure on the eastern flank of the play, which covers the Tathra Terrace in EP503, 504 and 505. The thickness and quality of the ED-1 result at depths of ~5,000m also improves the prospectivity of much of Strike’s acreage.

Earlier this year Strike acquired the 479 km Kadathinni 2D seismic survey over the ArrinoKadathinni leads. Early versions of the seismic show positive imaging at Permian level with definition of the major fault systems that support the structural extensions from the Lockyer and Erregulla gas fields. 

Strike’s Managing Director and Chief Executive Officer Stuart Nicholls said:
“The discoveries at Erregulla Deep are higher quality than Strike anticipated prior to drilling, with reservoir quality, formation pressures and lower CO2 content all exceeding expectations relative to the West Erregulla wells.

The Erregulla Deep-1 well is the most easterly and deepest penetration of the Kingia-High Cliff Sandstones in the basin to date and is a significant play extender to the East and at depth for Strike’s 100% acreage. 

Erregulla Deep will be completed as a future producer and on a successful flow test may add to the overall developable resource in EP469 / L25, which includes the West Erregulla gas field’s independently estimated gross 452 PJ of 2P Reserves plus 2C Contingent Resources.” 

KeyFacts Energy: Strike Energy Australia country profile