Independent certifiers Nertherland, Sewell & Associates estimated the fields had total proved, probable and possible (3P) reserves of 433 petajoules. That is a 30% increase on the 3P reserves originally attributed to the Meridian SeamGas JV when it assumed operatorship last July.

Proved and Probable (2P) reserves were up 20% based on WestSide’s calculations to 244PJ. That reflected the reclassification of some proved (1P) reserves due to a lack of development work in the 18 months prior to WestSide assuming control of the fields.

WestSide chief executive officer Julie Beeby said the updated reserves estimate did not take into account exploration and production drilling work carried out at the project since the acquisition and did not include about seven coal seams present above 1000m or any seams below that depth.

She said WestSide was targeting a reserve upgrade by the middle of this year and remained confident the work programs in place would achieve a rapid maturation of project’s certified reserves.

The Meridian SeamGas JV is targeting an additional 200PJ of 2P reserves by June 30.

WestSide holds a 51% interest in the Meridian SeamGas CSG fields, with Mitsui E&P Australia holding the remaining 49%.