ASX-listed Strike Energy has inked a 300% increase in its net reservoir within the secondary objective Wagina sandstone to 10.2 metres with porosities of up to 14% at its multi-target West Erregulla-2 well in the Perth Basin, Western Australia.
The upgrade came after the company carried out a further interpretation of wireline logs using proven regional cut-offs taken from nearby fields such as the producing Beharra Springs project.
Strike was initially only able to confirm a net pay of 2.5m at the top of the formation due to poor hole conditions.
Recent wireline logs also indicated that the net reservoir can be subdivided into a higher quality upper zone and a more dispersed lower porosity zone.
Management said that along with drilling observations that confirmed that the reservoir pressure is more than 6,800 pounds per square inch, the inferred reservoir properties support the potential for material flow rates when the formation undergoes production testing.
Additionally, West Erregulla-2 has since intersected additional gas-bearing sands in the Wagina sandstone prior to reaching the Carynginia shale, which increases the gross gas column intersected to date to 79m.
Beharra Springs and its associated fields, located just 9km from West Erregulla-2, were discovered during the 1990s and flowed gas at rates of up to 38 million cubic feet per day with reservoir pressures of about 5,780 pounds per square inch during flow testing.
This flow was sourced from a 10.4m net gas column in the Wagina sandstone with porosities of about 9.5%, which the company said compares very favourably with West Erregulla-2.
Strike said that the Beharra fields are typical bimodal reservoirs, where a thick, low porosity gas-charged sand underlies a thinner, highly productive upper section, which is similar to the Wagina hydrocarbon section observed at West Erregulla-2.
The continual ‘recharge’ from the lower section into the upper is believed to be the reason for the Beharra fields significantly exceeding their originally estimated recoverable reserves.
Strike is currently drilling West Erregulla-2 towards the primary target which is known as Kingia-High Cliff sands that are interpreted to be of a similar size and nature to the same sands at the nearby Waitsia gas discovery.
Managing Director Stuart Nicholls said: “The recent developments in our understanding of the Wagina discovery at West Erregulla are very exciting. When the results are compared to those from Beharra Springs, the analogue is clear and favourable.”
“This is a significant gas discovery given the observed and interpreted quality of the formation and over-pressured reservoir. We are encouraged by the results to date and look forward to a future flow test which would allow for a declaration of a contingent resource.”
By Matt Birney
