NZEC’s 903-square-km (223,086-acre) Ranui Permit holds the most significant well drilled in the East Coast Basin to date. In late 2010, NZEC acquired a 100 percent working interest from the previous permit holder.
Ranui-1 is a strategic opportunity for NZEC. No other modern-era wells have penetrated this shale, which is estimated to be up to 600 metres thick. The permit is estimated to contain OOIP of 969.0 million barrels and best estimate recoverable unconventional resources of 22.5 million barrels (2% recovery rate), as well as OOIP of 198.3 million barrels and best estimate recoverable conventional resources of 18.0 million barrels (9% recovery rate).
The Ranui-1 well was drilled in 2008 by the previous permit holder. It targeted a conventional sandstone anticline identified on 2D seismic but instead intersected the Whangai shale, which underlies more than half the permit area. The Ranui-1 well was drilled to a total measured depth of 1,135 metres. Analysis of well cuttings suggested the presence of natural gas, condensate and oil over a 224-metre vertical column in the Whangai shale. The operator suspended operations because of financial difficulties.
NZEC drilled the Ranui-2 well in January 2012 to a target depth of approximately 1,500 metres with the objective of reaching the base of the Whangai shale and collecting core from selected intervals. Coring is focused on gathering additional information about the Whangai shale and identifying areas of greatest reservoir potential. NZEC also shot 70 km of 2D seismic in 2012 across the Ranui and Castlepoint permits with the objective of pinpointing well locations for 2013 exploration.