Oil sands are a combination of sand, clay, water and bitumen, which is a sticky, black and highly viscous form of petroleum. Bitumen acts rather like cold molasses at room temperature and is generally too thick to be pumped without diluting or heating it first.
Oil sands can be found in many countries, but they’re most associated with
Canada, where bitumen deposits have been found in extremely large quantities. Of the world’s estimated total oil sands reserves (some 249.67 Gbbl), over 70% is thought to be in Alberta, Canada. More importantly, Canada is actively recovering oil from its oil sands, with upgraded and non-upgraded bitumen accounting for 62% of its total oil production in 2015.
Oil sands have only recently been considered as proven oil reserves, mostly thanks to improved extraction technology and higher oil prices, but bitumen has been used as far back as Palaeolithic times. The earliest known example use was about 40,000 years ago, based on Neanderthal stone tools that were found in sites in Syria with bitumen on them. It was also used by the Sumerians and Babylonians to waterproof boats and buildings.
Only a fraction of the extra-heavy oil or bitumen can be extracted with conventional oil well technology, so oil sands production generally focuses on surface mining or complex in-situ techniques. Canada’s Athabasca oil sands are currently the only major deposit suitable for surface mining. The development of Steam Assisted Gravity Drainage (SAGD) in the 1980s proved to be a big breakthrough for the industry. It’s suitability for a wide range of areas and economic feasibility meant that Canada’s proven oil reserves became the second largest in the world, although it is now number three since Venezuela also included its own oil sands reserves.
The technology to exploit oil sands continues to improve in terms of efficiency and reduced environmental impact. ExxonMobil, which also makes anti-wear hydraulic oils like Mobil DTE 25, and its Canadian affiliate Imperial Oil Limited are leading players in emerging technology for oil sands production. For example, their new Kearl operation employs advanced mining techniques and energy-saving cogeneration. It also produces diluted bitumen without the need for an upgrader, resulting in life-cycle greenhouse gas emissions that are equivalent to many oils refined in the United States.
While current oil prices may not favour oil sands production, Canada’s oils sands present a sizeable, secure energy resource to power North America’s economic growth in the coming decades.