La oil extraction varies significantly depending on geography, type of deposit, and the methods used. In some places it is easier and less damaging to the environment than in others. One of the most complex and controversial forms of extraction is that of tar sands oil, a resource known for its negative environmental impact and technical challenges.
What are oil sands?
The oil sands are deposits of a mixture of sand, clay, water and bitumen. The latter is a form of heavy and extremely viscous oil It does not flow freely at room temperature, making its extraction much more complicated than that of conventional oil. These sands are usually found in deposits close enough to the surface for mining or in underground deposits that require advanced technologies for extraction.
The main deposits are located in Canada, especially in the province of Alberta. Specifically, the Athabasca, Cold Lake and Peace River regions concentrate the majority of the reserves. Significant deposits can also be found in Venezuela, in the famous Orinoco Oil Belt.
Oil extraction in tar sands
Oil production from oil sands has two main extraction methods: open pit mining and in situ recovery methods such as Steam assisted gravity drainage (SAGD).
Opencast mining
This method is used when the bitumen is less than 70 metres deep. Heavy machinery is used to remove large quantities of sand and then transport the material to facilities where it is processed using large quantities of hot water and diluents. The bitumen is separated from the sand, clay and water by gravity, after which it is sent for refining.
This process is highly destructive to the environment, which has generated opposition from environmentalists due to massive deforestation and the creation of large toxic waste ponds.
Steam Assisted Gravity Drainage (SAGD)
When the oil sands are deeper than 70 metres, the SAGD method is used. This process involves drilling two parallel horizontal wells. The upper well is injected with steam to heat the bitumen, which then flows to the lower well, where it is extracted.
This method is less invasive at surface level than mining, but still has an environmental impact as it requires significant amounts of water and energy to generate the steam.
Environmental Impact of Oil Sands Production
La oil extraction from tar sands It is one of the most polluting methods of oil production. In addition to requiring a large amount of energy and water, the process releases Emissions of greenhouse gases much higher than conventional oil. According to studies, the combustion of fuels derived from bitumen emits between 15% and 23% more CO2 than unprocessed oil.
In addition, many of these reserves are located under boreal forests, which are often deforested to allow for oil extraction. In Canada, direct impacts on wildlife such as the caribou and the bear, especially in the Athabasca area. Likewise, the creation of toxic waste piles has contaminated bodies of water such as the Athabasca River, affecting communities Cree indigenous people that depend on these resources.
One of the biggest environmental disasters associated with this industry is the creation of toxic waste ponds which include substances such as mercury, arsenic and lead. These ponds already cover more than 170 square kilometres in Alberta.
Opposition and controversy over oil sands
The exploitation of tar sands is a widely debated topic in politics and ecology. While countries such as Canada and Venezuela depend on these reserves to maintain their energy independence and strengthen their economies, the environmental damage is undeniable.
In Canada, concerns about projects such as the Frontier mine in Alberta have reached the international organizations, including UNESCO and ecological associations such as Friends of the EarthThis organization, along with many others, denounces the massive felling of forests, water pollution and the violation of the rights of indigenous communities.
Economic debate
El bitumen sands oil It is essential to Canada's economy, which has 160 to 170 billion barrels of oil in these sands. This makes Canada the third country with the largest oil reserves in the world. Despite the negative impacts, the exploitation of these resources contributes significantly to the country's economy.
Bitumen extracted from oil sands is seen by some governments as a strategic resourceHowever, other countries and organizations have begun to show resistance to importing this type of oil due to its effects on global warming.
In countries like the United States, the debate revolves around the pipeline construction which may be essential for energy security, but pose risks in terms of pollution and displacement of local populations.
The oil pipeline Trans Mountain It is one of the most controversial pipelines in Canada, as it runs through indigenous territories and protected areas. Although its development promises to increase crude oil transport capacity, protests and environmental concerns have repeatedly delayed its construction.
The expansion of these infrastructures could lead to an increase in Alberta's oil production, which has already reached 4,2 million barrels per day, placing this region as one of the main crude oil producers worldwide.
Although oil sands exploitation remains an important source of oil for several countries, its effects on the environment cannot be ignored. International pressure to find more sustainable methods or to restrict its production in favour of cleaner alternatives is likely to intensify in the coming decades.