AWE: Gas discovery at Waitsia-3 confirms extension to field By Martin Kovacs, 4 Jul 2017

AWE, operator of L1/L2 in the Western Australian northern Perth Basin, has advised that a gas discovery at the Waitsia-3 appraisal well has confirmed the southern extension of the Waitsia gas field.

AWE advised that preliminary analysis of wireline log and pressure data from Waitsia-3 confirmed the extension “by encountering strong gas shows across a 150 m gross interval including the Kingia and High Cliff Sandstone reservoir targets”.

Waitsia-3 was drilled to a total depth of 3,612 m MDRT into crystalline basement, AWE stated, with the Kingia reservoir penetrated on prognosis at 3,211 m MDRT, and the High Cliff Sandstone intersected 80 m deeper than predicted at 3,362 m MDRT as a result of a thicker-than-expected section of Kingia Sandstone and Bit Basher Shale.

AWE advised that three sections of core were cut in the Kingia reservoir, with all cores sent for analysis, while the well has been cased and suspended for future testing and production.

Kingia reservoir preliminary interpretation “shows excellent conventional reservoir qualities, among the best observed in the field to date, and considerably better than pre-drill estimates”, AWE stated, with the gross reservoir interval of 52 m containing 20 m of net gas pay, with the reservoir quality exceeding that intersected in Waitsia-1 and Waitsia-2.

“The Kingia net reservoir interval in Waitsia-3 is approximately double that observed in other wells in the field and confirms the laterally extensive nature of this excellent reservoir, which is particularly encouraging given the large step-out from previous wells,” AWE stated.

The High Cliff Sandstone reservoir interval was gas-bearing, however thinner than predicted, with preliminary analysis indicating a tight reservoir, AWE advised, and, while no gas-water-contact (GWC) was intersected in the well, gas has been observed to the base of the High Cliff Sandstone at 3,360 m total vertical depth subsea-level, 10 m below the GWC previously interpreted over the rest of the field, which “may indicate substantial further upside in the field”.

AWE advised that two gas samples were recovered to surface from the Kingia reservoir, with preliminary compositional analysis indicating total inerts are below 7%.

“The Waitsia-3 appraisal well has significantly exceeded our pre-drill expectations,” AWE CEO and Managing Director David Biggs commented. “The substantial thickness of the Kingia reservoir, combined with exceptional porosity, net pay and low levels of total inerts, confirms excellent reservoir quality in the southern extent of the Waitsia field.

“The observation of gas below the previously interpreted GWC may also have positive implications for the rest of the field and provide new appraisal and exploration opportunities within the permits. We will continue our analysis and evaluation of the Waitsia-3 data, but we are already looking ahead to the Waitsia-4 appraisal well, which is expected to spud in the first half of July.

“The combined data from Waitsia-3 and Waitsia-4 will allow us to review our estimated reserves and resources for the entire Waitsia field and, subject to Waitsia-4 results, we anticipate a further upgrade to reserves within the second half of calendar year 2017.”