Lake Erie's Hidden Hydrocarbons

Beneath Lake Erie is a wealth of oil and natural gas, giving rise to an industry that many local people don't realize exists in their own backyards.

Photo: Mark Conboy

I came to live on Lake Erie a year and half ago. After a term as an environmental consultant working on various oil and gas developments in Alberta, I decided that an industrial job and big city life weren't ideal, so I said goodbye to the boreal forest, the Rocky Mountains, the great spreading plains, and moved east, far from the oil and gas heartland. But I was very soon to realize that Lake Erie, was in fact an oil and gas hub all its own.

Now, this wasn't a total surprise, but it was something I hadn't really considered. I knew, of course, that Canada's first hydrocarbon company had been established to make asphalt from near-surface tar deposits at Petrolia, Ontario. By 1858, the first true oil wells in all of North America were dug in southern Ontario near the town of Oil Springs (it wasn't until the following year that the American oil crazy took off when Edwin Drake famously drilled into a pressured reservoir at Oil Creek, Pennsylvania). The sight of oil pumpjacks and natural gas well heads spread out across the countryside was nothing new to me either. But, I admittedly got a big surprise when I unfolded a nautical chart of Long Point Bay, and saw the maze of pipelines which crisscrossed the lake bed, connecting dozens of gas wells. It had never occurred to me, that there was an offshore hydrocarbon industry on the Great Lakes. Then again, why shouldn't there be? Offshore ocean oil and gas industries exist all over the world, and with oil and gas deposits to the north and south of Lake Erie, it should have been obvious.

But the offshore oil and gas industry on Lake Erie isn't obvious. There are no permanent oil platforms. Natural gas drilling rigs are modest-sized barges that only take a week or so to dig a well and bring it into production, so their presence on the lake is not all that intrusive. Well heads and pipelines lay on the bottom of the lake, completely out of sight, aside from the small white buoys that mark their presence. Indeed, many people who live on Lake Erie have no idea that an offshore oil and gas industry exists.

There are close to 500 natural gas wells (and far fewer oil wells) currently in operation on the Canadian side of Lake Erie, though several thousand have been drilled since production began in 1913. In fact, almost the entire offshore oil and gas industry is based on the Canadian side of the Great Lakes. The only state which currently allows offshore production is Michigan, but all of the wells under Lake Michigan are drilled from shore. In Ontario, oil is harvested from Lake Erie using the same kind of shore-based technique, called directional drilling. This involves drilling vertically to desired depth, then drilling horizontally under the lake bed, sometimes for many kilometres, through the oil-containing rock formation. Once a well is operational, the oil is pumped directly back to shore. In this way, the risk of an oil spill is kept to an absolute minimum. Typical drilling for natural gas uses another approach. In this case specialized barges drill vertically into the lake bed. Once the drilling is done, the well is capped and connected to shore via a pipeline. There are some 890 km of pipelines in operation under Lake Erie today. Some directional drilling may be employed for natural gas as well, but given the reduced environmental contamination risks of natural gas, most drilling can safely occur offshore. Most wells are expected to produce for 10-20 years.

Major oil and natural gas pipelines in Lake Erie.

Map: Offshore Magazine

Lake Erie oil and gas is extracted from Silurian aged rocks, 419-444 million years old. When these rocks formed, Ontario was a very different place. The province was located some 6000 kilometres south, at approximately the same latitude where Bolivia sits today. Though having the enviable geography of a tropical paradise, Silurian Ontario would have been amazingly devoid of terrestrial life, because it would still be another few hundred million years before land plants and animals became abundant. Silurian ocean life was plentiful however, with fish diversifying rapidly and microscopic marine algae providing the foundation for food webs, just as it does today. For at least part of the Silurian, southern Ontario was covered by a relatively shallow tropical sea. It was from this sea that Lake Erie's oil and gas deposits arose. Dead organic materials, in this case Silurian marine algae and animals which become buried under layers of sediment are transformed into oil over millions of years through exposure to phenomenally high temperatures and pressures. Over time, exposure to heat and pressure chemically alters the trapped organic material, turning it into oil. In effect, when we use Lake Erie oil for fuel we are essentially burning ancient algal blooms, with perhaps a smattering of fish, sea scorpions, crinoids, mollusks and brachiopods mixed in. Natural gas that is harvested from beneath Lake Erie was formed in the same way oil, but gas can also be formed through the anoxic decomposition of organic matter under much simpler conditions such as in a bog or swamp, and during digestion by animals. Even humans create their fair share of natural gas; natural gas is simply methane, after all.

The Silurian rocks which contain Lake Erie's oil and gas are buried between 100 and 1100 meters below the lake bottom. Two types of natural gas are produced: at the eastern end of the lake sandstones and shales produce sweet gas, or natural gas that doesn't contain poisonous foul-smelling hydrogen sulfide. In the western half of the lake a series of ancient patch reefs, 10-40 metres thick produce sour gas, natural gas which does contain hydrogen sulfide. It's not uncommon for people to picture reservoirs of oil or gas as underground lakes. But that's not the way it is at all, in fact, the oil and gas are within the rocks themselves, filling tiny pores. The sandstones and shales, which are made of compacted and lithified Silurian sand and mud, respectively, are full of pores and those pores are full or oil and gas. The oil and gas didn't form inside those pores, but migrated there from their over long periods of time from its original location. Just as coffee percolates through a filter, oil and gas percolate their way through porous rock formations, some escaping to the surface, some getting trapped under impermeable layers of rock building up in large enough quantities for us to extract it economically. The formation of oil and gas deposits is a surprisingly dynamic process, only it takes place over such extraordinary timescales that it seems static from the typical human perspective. 

Compared to Alberta, Ontario's oil and gas industry is tiny. Virtually all of the production from Lake Erie's oil and gas fields is used in Ontario, but that only amounts to 1% of the province's annual oil consumption and 2% of annual gas consumption. Small potatoes. And thank goodness for that. Because, no matter how carefully an industry is regulated and no matter how much effort is made to reduce the risk of environmentally damaging oil spills, accidents do happen and when they happen in an offshore environment they can devastate ecosystems and be all but impossible to clean up. Spills and leaks seem to be relatively uncommon but they do occur in Lake Erie from time to time. Coming up with exact numbers for recent years isn't easy, but there are always a couple of small incidents annually.

Beyond the problem of oil spills and gas leaks, sedimentation, primarily from drilling waste, is another potential environmental concern. When wells are drilled, tailings in the form of sand, mud, rock particles and drilling fluids are released into the lake, where they can cause localized sedimentation. Whether this is a major problem for wildlife is unclear, but given that less than one hundred new wells are dug in the average year on Lake Erie, it probably is not. Compared to the uncounted tonnes of sand that is carried around the lake naturally by winds, currents and erosion, the harm caused by drilling sediment must surely be negligible, or at least very localized. That being said, drilling fluids do contain chemicals that are known to be harmful to humans, and unfortunately they are released (at least in some cases) directly into the lake; why exactly this is allowed and what health consequences may result is unclear.

Although Alberta (and to a lesser extent British Columbia and Saskatchewan) is the focus of Canada's oil and gas industry, southern Ontario is its birthplace. Lake Erie's small but sustained production has, for better or worse, kept the industry alive in Ontario for more than a century, even if it is relatively unknown.