Bitumen mining makes up 63% of crude oil production in Canada. Naturally, it makes up the largest portion of production in Alberta, too.
And as long as this is the case, it’ll be a challenge for Alberta to significantly reduce its impact on the environment, particularly greenhouse gas emissions. Bitumen extraction and refining is an energy intensive process.
Consider conventional oil extraction. It’s most energy intensive during the drilling process and the refining process. But once the well is drilled and tapped, very little energy is expended to extract the oil.
Compare that to bitumen extraction.
Mining bitumen is done in one of two ways: surface mining and in situ extraction.
Surface mining is reserved for bitumen sands with deposits within 70 metres of the earth’s surface. Heavy machinery scoops the bitumen sands from the deposits and into large haulers, which look like gigantic dump trucks. Both the shovels and the haulers require energy. Unlike conventional wells (which is energy intensive during the construction phase), surface mining requires ongoing energy needs.
The haulers transport the material to a crushing facility, where the dense material is broken up to make transportation and processing easier. It’s then transported along conveyor belts to storage facilities, and then later to preparation plants. The crushing facility uses energy to operate the machines, the conveyor system uses energy to transport the material, and some storage facilities require energy when receiving material.
The preparation plant also requires energy, as it adds heated water (often using natural gas) to the material to create a slurry that can be pumped to the extraction stage. It also uses energy to run the preparation equipment, and energy is used to transport the slurry to the extraction stage, as well as in the extraction stage, where any remaining water and solids are removed.
In situ extraction is a type of drilling, so there’s the initial energy requirement of the actual well construction. However, once operational, it uses steam to heat up bitumen, which helps it flow more easily, allowing it to be extracted to the surface. That steam is typically generated using natural gas. In situ also uses pumps to help get the bitumen to the surface, which requires energy.
Both bitumen from surface mining and in situ extraction eventually end up in an upgrader, which uses temperature, pressure, and chemicals—all of which require energy—to prep it for transport to refineries. (To be fair, some pipelines can transport pre-upgrade bitumen).
Bitumen mining in Alberta is a very energy intensive process, when compared to conventional oil wells. And until that changes, it’s going to be tough to reduce energy consumption in this province.
Read more here:
- Oil extraction (Canadian Association of Petroleum Producers)
- Crude oil facts (Natural Resources Canada)
- Oil sands 101 (Government of Alberta)