The continental margin of Atlantic Canada stretches on for more than three thousand kilometers from Georges Bank, at the Canada United States border to the northern tip of Labrador. Theoretically, all the basins along the margin can be considered to have hydrocarbon potential, most are lightly explored. Up to now, world class discoveries have been made in the Labrador, Jeanne d'Arc and Scotian Shelf basins.
Exploration drilling on the Atlantic Canada margin began in mid 1960's, and to date over three hundred exploration wells have been drilled, the vast majority on the continental shelf of Nova Scotia with an equal number in the waters of Newfoundland and Labrador. Currently oil production from the Grand Banks, is 55,000m3 (350,000 bbls.) per day is produced from the Hibernia and Terra Nova oilfields with the White Rose field set to start production in late 2005 at around 16,000 m3 (120,000 bbls.) per day[1].
Gas production in Nova Scotia is around 12.5 million m3, (450 million ft3) per day from four gas fields; Venture, Thebaud, North Triumph and Alma, with additional fields to be on-stream in the next few years.
To date, the industry has drilled ten deepwater wells, offshore Nova Scotia; four in the mid 1980's and six since the year 2000. Reserves are estimated by industry experts to have a mean reserve of 41 Tcf, unrisked in twelve distinct play types [2].
One deepwater discovery has been made at, Annapolis G-24, the first deepwater well drill in the new exploration round; unfortunately this success has been followed by a string of disappointments.
Exploration of offshore Nova Scotia, Canada began in 1959 with initial airborne magnetometer programs conducted by Mobil Oil Canada over the Sable Subbasin, Figure, 1. The first seabed sampling and seismic reflection programs followed in 1960 and identified the existence of the Sable Subbasin. The first drilling took place in 1967 on Sable Island, a small Pleistocene remnant 200 kilometres from Halifax, Nova Scotia and confirmed the existence of reservoirs and source rocks within the basin.
Since that first well in 1967 a total of 199 exploration, delineation and development wells have been drilled offshore in an area of approximately 120,000 km2. The major area of focus for exploration has been the Sable Subbasin, an area of 10,000 km2 in water depths of a few metres to 200 metres where all but two of the significant discoveries have been made to date, Figure 1.
The most recent, shallow-water gas discovery, Deep Panuke, is the only Jurassic-aged carbonate discovery on the western Atlantic margin to date, although hydrocarbons are found in similar play offshore Morocco, the conjugate margin to Nova Scotia. This discovery, under the existing and depleted Cohasset and Panuke oil fields, was made in 1998, and has been delineated by seven additional wellbores by PanCanadian and the successor company, EnCana Corporation.