Exploration - The First Decade
In 1992 ACM was granted Petroleum Exploration Licence 286 which filled the tenure gap between ground held in the upper Hunter Valley and the Gunnedah region to the north. PEL286 straddled the Liverpool Range and seam gas potential was indicated to be at significant depths or in areas of structural complexity. When tenure further north was relinquished, ACM successfully applied in 1992 for an area that was granted as PEL1. (Following introduction of the new Petroleum Act in 1992, the tenure numbering system was reset.) Additional tenure in the form of PELs 10 and 12 were added in subsequent years to form a contiguous block of more than 11,000 square kilometres.
Pacific Power (formerly the NSW Electricity Commission) joined ACM in a joint venture arrangement (ACM 80% and Operator) and in 1993 the first dedicated seam gas exploration well in the Gunnedah Basin - ACM West Quirindi DDH1 - was drilled. This well was followed by a further six cored wells spread over PELs 1 and 12 prior to cessation of the joint venture as a consequence of the winding up of Pacific Power by the NSW Government in 2003.
During this period the vast amount of data from coal exploration drilling in the region was systematically compiled, seismic data acquisition was trialled, and desorption and permeability testing of a number of coal exploration drillholes sunk by the NSW government in the Caroona region was undertaken by the ACM/PP JV. The latter work indicated relatively low gas contents but high seam permeabilities, leading to the recognition of the biogenic gas potential of PEL1.