Canada's Oil Sands - Centre for Energy

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Section 2 A Massive Task Conventional crude oil flows naturally or is pumped from the ground, but oil sands bitumen does not flow at room temperature and must be mined or recovered in-situ. Deposits close to the surface are mined; those more than about 75 metres below the surface require in-situ recovery. Current in-situ bitumen production generally comes from deposits more than 400 metres below the surface. Many of the technologies used in oil sands extraction are similar to those in other surface mining and conventional oil and gas operations, but they are deployed on a massive scale and sometimes in unique ways. Industry and government research and development has also led to many entirely new technologies for recovering and upgrading bitumen. 10 CANADA’S OIL SANDS THIRD edition november 2011
Mining shovels dig into sand and load it into huge trucks. Trucks take oil sands to crushers, where it is prepared for extraction. In some operations, a mobile crusher near the shovel may eliminate the need for trucks. Hot water is added to the oil sands and then fed via hydrotransport to the extraction plant. Bitumen is extracted from the oil sands during hydrotransport and in the separation vessels. The tailings are pumped to the settling basin, where most of the water is recycled. Mining About 20 per cent of Alberta’s economically recoverable oil sands bitumen reserves are close enough to the surface to make mining feasible. These are all located in the Athabasca oil sands area north of Fort McMurray. An advantage of mining is that nearly all of the bitumen is extracted from the ore, while in-situ methods leave a substantial amount of the resource underground. A disadvantage is that a great deal of earth and ore must be moved, disturbing significant areas of landscape. To achieve economies of scale, the projects are very large. Each of the operating mining projects also has an upgrader on site or is connected to an upgrader by pipeline. The ore in the current projects’ lease areas averages about 10 to 12 per cent bitumen by weight. Thus nearly two tonnes of oil sands are dug up, moved and processed to make one 159-litre barrel of upgraded crude oil. The processed sand is then returned to the pit, and the site reclaimed. A big part of the mining operation involves clearing trees and brush from the site and removing the overburden – the topsoil, muskeg, sand, clay and gravel – that sits atop the oil sands deposit. This can amount to more than two tonnes of additional material that needs to be moved in the course of producing one barrel of upgraded crude oil. The topsoil and muskeg are stockpiled so they can be replaced as sections of the mined-out area are reclaimed. The rest of the overburden is used to reconstruct the landscape. The oil sands are highly abrasive and very hard on machinery. Literally tonnes of steel are worn away from the equipment each year. Regular maintenance is expensive but vital to a profitable operation. When the Suncor and Syncrude projects were built in the 1960s and 1970s, they used giant excavators called bucketwheels and draglines to dig up the oil sands ore and kilometreslong conveyor belts to move it to bitumen extraction facilities. They used this system because, at that time, the largest mining trucks carried less than 60 tonnes in a load. However, the excavators and conveyors were expensive to operate and suffered frequent breakdowns, especially in cold weather. In the mid-1980s, Syncrude started using trucks and power shovels for a portion of its oil sands mining. In 1993, Suncor switched its entire operation to a system that used the world’s largest trucks and power shovels. Each truck by then could carry up to 240 tonnes in a single load. Syncrude began phasing out its draglines and bucketwheels a few years later and retired the last of its draglines in 2006. CANADA’S OIL SANDS THIRD edition November 2011 11
Page 1 and 2: Canada’s Oil Sands Third Edition
Page 3 and 4: Contents Section 1: RESOURCES BEYON
Page 5 and 6: As of July 2011, there were 92 acti
Page 7 and 8: The continental and global context
Page 9 and 10: Challenges The economic, environmen
Page 11: To this end, the Alberta government
Page 15 and 16: In-situ bitumen More than 80 per ce
Page 17 and 18: Firefloods There has been some prod
Page 19 and 20: Co-generation is the simultaneous p
Page 21 and 22: gross sales revenues on all product
Page 23 and 24: Section 3 Towards Sustainable Devel
Page 25 and 26: light of achieving Alberta’s long
Page 27 and 28: The industry-funded, multi-stakehol
Page 29 and 30: dioxide in areas close to the oil s
Page 31 and 32: oil sands area, and industry has ma
Page 33 and 34: The path ahead North Americans have
Page 35 and 36: Mitchell, Robert; Brad Anderson, Ma
Page 37 and 38: Key definitions Hydrocarbons are co

Canada's Oil Sands - Centre for Energy

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