East Coast Basin, New Zealand

Basin Background: A Perspective
The East Coast Basin is a Cretaceous-Cenozoic fore-arc basin situated across the Australian-Pacific plate margin. Basins of this type can be prolific producers of oil and gas, as in Indonesia, California and other active plate margins worldwide. There are very few wells drilled in the East Coast Basin (one well per 800,000 acres), but the majority of these had significant oil and gas shows, including two of the offshore wells. One onshore gas discovery, with flow rates of up to 12 million cubic feet gas per day, is now under appraisal by Energy Corporation of America in the neighboring acreage.

Conventional Opportunities
Conventional reservoir targets include Miocene - Oligocene aged turbidite sandstones with porosities up to 30% or more, and fractured carbonate reservoirs that can be highly over-pressured. At least 50 conventional prospects and leads have been identified across the acreage with a number of large prospects like the Boar Hill, Pauariki, KawaKawa, and the Arakihi Anticline prospects directly overlying primary unconventional prospects. This sets up multi-target exploration with many of our upcoming wells in the East Coast Basin. Sproule International Ltd. estimates the undiscovered conventional resource potential in TAG Oil's permits to be in excess of 1.7 billion barrels.

Widespread Unconventional Frontier
Unconventional prospects are widespread across the acreage and exist in the late Cretaceous to Paleocene-aged Waipawa Black Shale and Whangai Shale source rock formations. Recent field and subsurface core studies have confirmed these world-class source rocks are not only rich in Total Organic Carbon (TOC %), they are also heavily fractured in many locations, which is one key factor in successful fractured oil shale production. Many of the active oil and gas seeps situated within TAG’s East Coast Permits have been geochemically tied to these rich underlying source rocks, confirming the validity of these unconventional targets as viable hydrocarbon prospects.