If you walk in a forest or a trail near you, you may notice a greasy substance flowing from a rock or even into a stream. Is it pollution? Probably not! Indeed, during our last blog post on hydrocarbon formation formation des hydrocarbureswe talked about the Source Rock essentially, but what happens next?
The oil and gas formed in the Source Rock suffers enormous pressures due to the weight of the rock that has accumulated above it. As oil and gas are lighter than water and rock, these migrate upward with the formation water (from the old sea).
So there are two possibilities 1) Oil and natural gas are trapped by a Reservoir-Rock which is covered by a waterproof layer or 2) There is no Reservoir-Rock or impermeable layer. This second possibility, which is most common, then produces a natural phenomenon that since millions of years and which is called natural surface seeps.
The figure below comes from a very good article from the Ministry of Energy and Natural Resources (MERN) and highlights the natural nature of the seeps, i.e. without human intervention.
Natural seeps are the first indices for geologists seeking hydrocarbons from the potential presence of subsurface reservoirs.
In the Province of Quebec, many areas have long been known to be teeming with natural hydrocarbon seeps. For example the Gaspésie (Northern Peninsula and Gaspé Bay), La Mauricie (The Devil’s Fountain), the St. Lawrence lowlands between Montreal and Quebec where methane was measured by the government in 1966 in drinking water in thousands of wells, and in the St. Lawrence River where several methane seeps have recently been identified by the Geological Survey of Canada. All these indications show that the potential for hydrocarbons in Quebec is far from negligible and deserves to be studied carefully.
The seeps are 100% natural phenomena! So when you walk in the woods, keep an eye open, you never know, you may find the future big oil field Quebecers!
Do you have any questions about this scientific note? You can contact the Squatex team at any time to answer your questions!
For questions of a scientific nature:
Alexandre Aubiès-T., PhD., Geo.
For media Inquiries:
Jean-François Thibault, ing. jr
Comments are closed.