East Coast Province
Two Onshore Blocks 13EC1 and 13EC2 cover a total area of 1,320.6km2 of the East Coast Province, which extends for at least 180,000 km2, incorporating the Raukumara, East Coast, and Pegasus basins.
The East Coast Province is geologically complex sitting in-between a modern subduction zone (and plate boundary) and the uplifted axial ranges of Mesozoic metasedimentary rocks.
The East Coast region has long tantalised oil and gas explorers since the late 1800s. More than 300 known oil and gas seeps attracted early interest from explorers and small volumes of oil were produced from shallow wells and pits near surface seeps at Waingaromia and Rotokautuku, north of Gisborne. More than 40 wells have been drilled onshore in the East Coast Basin, one of the early "successes" was Waingaromia-1, which produced 20-50 barrels of oil per day (bopd) until the rig burnt down in 1870.
Most wells since then have had shows of oil and/or gas. Offshore there were strong gas shows in the three offshore wells as well as gas finds in the onshore Wairoa area. These and other small finds have maintained exploration interest, although finding any sizeable accumulations has been problematic.
Recent developments of unconventional recovery technology has opened up the East Coast to the prospect of developing the Waipawa and Whangai "shale" Formations, that are known to be widespread throughout the province. Analogies can be made with the North American Bakken Shale, if these analogies are valid, then taking into account the fact that East Coast formations are thicker, this may make them highly productive with the estimated ultimate recovery per well potentially very high – i.e. in order of 1 million barrels of oil equivalent.
Gas hydrate layers occur in many offshore parts of the province. These accumulations, which cover up to 50,000 km2 or more, may hold vast quantities of methane.