Oil and Natural Gas Production in Ontario
And potential environmental concerns from legacy wells
The majority of Canada’s production of fossil fuels is from Western Canada. However, in the province of Ontario, there’s a long history of oil and natural gas production. The very first commercial oil well was established in 1858 in Enniskillen Township (near Sarnia, Ontario). Natural gas has been produced in Ontario since the early 1900s.
In the years since, Ontario has produced about 93 million barrels of oil and about 1.4 trillion cubic feet of natural gas (as of 2017). This includes about 330, 000 barrels of oil produced in 2017 (Canada produces about 4.5 million barrels per day). In 2020, Ontario produced an average of 6.9 million cubic feet of natural gas per day (less than 0.1% of Canada’s total in 2020). The graphs below show gas and oil production in Ontario since the early 1900s (reference here).
The numbers listed above reveal that Ontario doesn’t produce as much oil and gas as most other provinces. However, these resources continue to be viable and active in Ontario.
The Oil, Gas and Salt Resources Library (OGSRL) has over 27,000 wells on record in Ontario. This includes about 1,200 active oil wells, and 1,400 active natural gas wells (900 on land and 500 offshore). The map below (reference here) shows the locations of all the petroleum wells on record in southwestern Ontario. You can see many of these well locations are out in Lake Erie.
With approximately 27,000 petroleum wells on record and less than 3,000 active, this means that there are at least 24,000 inactive petroleum wells. When a well is abandoned, there are regulations on how to properly plug and seal the well. These regulations are in place to prevent the abandoned well from causing issues such as depressurizing geologic units or contamination between groundwater aquifers, for example.
However, many of these abandoned wells became inactive many years and decades ago, when such regulations did not exist. As a result, there are thousands of improperly sealed, inactive wells that could be causing environmental problems. In some instances, the proper location of an inactive well might not be known.
Inactive wells can represent a potential environmental hazard, such as:
leaking wells - petroleum products or by-products could leak to the ground surface
hydrogen sulphide gas - a toxic gas that can be released from leaking wells (rotten-egg smell)
groundwater contamination - improperly sealed wells can cause contaminated groundwater to move from deeper geologic units to shallower aquifers
In southwestern Ontario, there’s a well-documented incident where it is suspected that an improperly sealed abandoned gas well caused an explosion in the town of Wheatley, Ontario.
A little further east in Norfolk County, studies have shown that there are likely multiple abandoned wells that are contributing gas issues. Simply plugging one well might cause issues at another well. One land owner in Norfolk County has seen a large sinkhole develop on his property in addition to hydrogen sulphide gas and methane that are leaking from an old gas well. Here’s another article on the issues in Norfolk County. The photo below is from here.
So it’s a very complex issue. The oil and gas industry in Ontario grew very quickly in the early-to-mid 1900s and now, decades later, we seeing the adverse effects of improperly abandonment of these wells. The provincial and federal governments are struggling to keep up with the issues surrounding inactive oil and gas wells and some property owners purchased land without knowing there was an inactive well on site. The government should be paying to identify, locate, and properly seal these inactive wells, but because there are so many of them, this will be a time-consuming and costly endeavour.
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