Trenton-Black River hydrothermal dolomite reservoirs in Ontario : an assessment of remaining potential after 100 years of production

More than 19.5 million barrels of oil and 35 billion cubic feet of natural gas have been produced from the Trenton-Black River hydrothermal dolomite reservoirs in Ontario since 1900. This presentation assessed the Ordovician recoverable oil and gas reserves in southwestern Ontario. It involved the use of a truncated discovery process model to evaluate the geological delineation and statistics of the mature play. It was revealed that the total Middle Ordovician recoverable gas and oil resource is about 281 bcf and 39.7 MMbbls respectively. Of this gas and oil volume, 85 per cent and 43 per cent respectively remains to be discovered, suggesting that there is still vast potential for undiscovered oil and gas volumes, especially in the area between the current exploration and development area and the eastern point of the Niagara escarpment. Oil and gas pools are trapped in Ordovician carbonates of the Trenton and Black River groups. The linear hydrothermal dolomite reservoir is up to 14 km long and 1200 km wide. The proven recoverable reserves in individual pools are estimated at 6 million bbl of oil and 13.6 bcf of natural gas. This presentation reviewed the history of the resource play, tectonic framework, regional stratigraphy, and resource assessment procedures. It also presents a geological play definition, compilation of play data, a discovery process mode, well and pool size distributions, and an estimate of play potential in these prolific oil and gas reservoirs. 51 refs., 11 tabs., 15 figs.