Griffin, A.G. 2009 Overview of shale gas : exploration and exploitation characteristics and issues based on experience from the United States, and implications to New Zealand. Lower Hutt, N.Z.: GNS Science. GNS Science report 2009/70 72 p.
Abstract: Shale gas refers to unconventional thermogenic or biogenic methane contained in fine-grained, low permeability reservoirs in which the methane has been stored as free-gas in the matrix or fracture porosity, or as adsorbed/dissolved gas on the organics and/or clays. Unconventional refers to natural gas being contained in difficult-to-produce reservoirs, which often require special completion, stimulation and/or production techniques in order to achieve economic success. Unconventional gas resources are usually volumetrically large and occur over wide geographic areas. They are also found within low and/or variable permeability reservoir rocks, which are often closely related to the source rocks. Shale gas is one type of unconventional gas; other types include coal-bed methane and basin-centred gas. This report describes some of the different basins in the United States that are currently producing shale gas in commercial quantities, and provides an initial assessment of shale gas potential in New Zealand, in particular the East Coast, Taranaki, Great South and Northland basins. (auth/DG)