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Oil Sands Drilling Methods

Oil sand, also known as tar sand, is a form of soil that is made up of sediment laced with bitumen, a form of heavy oil, according to the American Association of Petroleum Geologists. Although oil sands can be found in many places, the world's largest deposit of oil sands is in Alberta, Canada, where it is frequently mined by oil companies. Special drilling methods are required to extract oil from oil sands.

Steam-Assisted Gravity Drainage
- Developed by the Alberta Department of Energy, steam-assisted gravity drainage uses two horizontal oil wells, with one drilled above the other, according to Halliburton, a large oil-extraction company. Operators inject steam into the top well to heat and separate the oil from the sand, and operators pump out the heated oil and water mixture through the lower well. According to Halliburton, the process leads to more efficiency and cost savings versus other oil sands extraction methods.
Open-Pit Mining
- According to the Oil Shale and Tar Sands Programmatic EIS, open-pit mining is the most efficient oil sands extraction method when large amounts of bitumen are present in the sand. The sands are transferred to an oil extraction plant, where they are placed in a "separation cell," which is a machine that separates the oil from the sand.
Vapor Extraction Process
- The vapor extraction process (VAPEX) is an oil sands drilling method similar to steam-assisted gravity drainage. VAPEX uses hydrocarbon solvents to dilute the bitumen content, making it more viscous and allowing it to flow so that operators can pump it out. The process also partially converts the bitumen into usable crude oil. According to Info Mine, VAPEX is much more energy-efficient than steam-assisted gravity drainage, but as of 2010 VAPEX is more expensive than other methods.

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