Öljyhiekka

Öljyhiekka, also known as tar sands or oil sands, is a type of unconventional petroleum deposit. It is a combination of sand, clay, minerals, and a viscous form of petroleum called bitumen. Bitumen is so thick that it does not flow like conventional crude oil and must be heated or diluted before it can be extracted and processed.

The largest known deposits of oil sands are found in Alberta, Canada, with significant reserves also present in Venezuela. Extraction of oil from oil sands is a complex and energy-intensive process. There are two primary methods: surface mining and in-situ extraction. Surface mining is used when the oil sands are close to the surface. Large excavators remove the oil sands, which are then transported to processing plants. In-situ extraction, primarily steam-assisted gravity drainage (SAGD), is used for deeper deposits. Steam is injected into the ground to heat the bitumen, making it flow more easily and allowing it to be pumped to the surface.

Once extracted, the bitumen undergoes a significant upgrading process to transform it into synthetic crude oil, which can then be refined into petroleum products. The environmental impact of oil sands extraction is a subject of considerable debate. Concerns include land disturbance, water usage, greenhouse gas emissions, and potential impacts on wildlife and ecosystems. Despite these challenges, oil sands represent a vast source of hydrocarbon resources, and their development continues to be a significant economic activity in regions where they are found.