The appraisal well was drilled to a total depth of 3370m, after originally intersecting the targeted Dongara/Wagina formation and drilling to 2760m.
The well was deepened after elevated gas shows were observed in the target reservoir, with multiple hydrocarbon-bearing formations encountered throughout the well.
Wireline logs and pressure tests have identified a potentially larger volume of gas in the lower secondary targets than has been intersected in the Dongara/Wagina, confirming a gas gradient over the Kingia and High Cliff sandstone formations.
Contingent resources in the Dongara/Wagina have been upgraded, with best estimate 2C resources revised upwards to 70 billion cubic feet of gas.
Additional analysis is still needed to estimate resources in the deeper formations.
"This is a very exciting discovery that adds considerable momentum to the near-term development potential of the Senecio gas field and other nearby prospects in the north Perth Basin," AWE managing director Bruce Clement said.
"The positive appraisal of the Dongara/Wagina reservoir and the discovery of a potentially larger new gas play in the deeper sands have increased the likelihood of commercial development of the Senecio gas field, particularly given the proximity to existing infrastructure.
"Gas production from the Senecio field with a low-cost tie-in to the AWE-operated Dongara gas plant, 7km to the west, would be a logical first step in commercialising unconventional gas in the onshore Perth Basin and would reinvigorate the gas industry in the Mid West of Western Australia.
"This discovery has materially upgraded the potential of other prospects in the area and the joint venture plans to drill the Irwin-1 exploration well to the east of Senecio later this year, targeting the same plays.
"We are prioritising the evaluation of the new gas discovery at Senecio and AWE is also evaluating the potential for a conventional flow test of Senecio-3 later in 2014."
Core samples and log data from the target formation will be fully analysed before the company makes a decision on field development, with fraccing still ruled out at this juncture.
