How much/ how little do you know about tar sands?

The structure of Athabasca Tar Sands (Czarnecki et al, 2005)

Tar sands are essentially sedimentary rocks that contain a varying combination of bitumen (a semisolid viscous hydrocarbon), quartz sand, water and clays. Quartz sands are the major constituent of this blend (83%), followed by the bitumen (13%) and water (4%). In its natural state, bitumen behaves as a viscoelastic solid, and it can be liquefied only by the application of hydrocarbon solvents or by a direct injection of heat (i.e. steam) into the underground deposits.

Geographical distribution

While tar sand accumulations are found in many locations worldwide, namely in Utah (USA), Republic of the Congo, Tatarstan (Russia) and the Middle East, the Canadian province of Alberta sits on 85% of the world’s known tar sands reserves. According to Alberta Energy (2011), the Canadian tar sands alone represent 13% of the world’s proven hydrocarbon reserves, covering 140,200 km2 of Athabasca, Cold Lake and Peace River regions and amounting to 175.2 billion barrels of oil.

Location of Canadian Tar Sands Resources (CERA, 2011)

Global consumption and production

According to the latest figures, oil sands currently accounts for over half of Canadian crude oil production, however their total share is expected to increase to around 80% by 2025.

Clarke (2008) maintains that Canada earned its ‘energy superpower’ title as a result of the North American Free Trade Agreement (NAFTA) with the United States. In compliance with NAFTA's Proportionality Clause, Canada makes two-thirds of its daily oil production available for export to the United States (Laxer and Dillon, 2008). Consequently, Canada has superseded Saudi Arabia as the largest supplier of crude oil to the U.S. (Nikiforuk, 2008), exporting one million barrels of oil (from tar sands alone) per day across the border. This number is expected to quadruple within the next 15 years.

Sinclair’s conclusion (2011) is that the investment protection rules in trade agreements such as NAFTA and the Can-EU Comprehensive Economic and Trade Agreement (CETA) not only pose a serious threat to Canada’s environment but also exacerbate global climate change.

In October 2011, the European Commission ranked fuel originating from oil sands as highly carbon-intensive, assigning it a greenhouse gas (GHG) value of 107 grams of carbon per megajoule (Article 7a, European Fuel Quality Directive). The GHG emissions of tar sands are therefore considered 23% higher that those of conventional crude oil (Sinclair, 2011).

Economic importance and uses

Unsurprisingly, around 60% of all multinational oil companies have laid claim to Alberta’s booming tar sands, constituting to a total investment of C$200 billion to date (Nikiforuk, 2008).

In 2011, the Canadian Association of Petroleum Producers (CAPP) has valued the total industry spending for oil sands development at $16 billion for 2011, which represents a 19% increase from 2010. Clearly, Alberta’s oil sands, expected to generate $1.7 trillion for the Canadian economy over the next 25 years, are driving the future growth of the country’s oil production. Nearly half a million Canadian jobs are associated with the development and management of tar sands operations.

Social, technological and environmental factors

Extraction methods

Tar sands can be recovered either by surface mining or through a number of in-situ collection techniques. The former began in 1964 when Suncor began the construction of a large-scale commercial extraction plant near Fort McMurray in Alberta. On the other hand, in-situ methods include relatively recent oil sands technologies, which have been in development by the Alberta Oil Sands Technology and Research Authority (AOSTRA) since the mid 1970s.

Essentially, the depth of oil sands determines the extraction technique applied; consequently surface mining is only suitable for shallow deposits where the overburden does not exceed 75 meters. Truck and shovel methods are used to remove shallow oil sands and the bitumen is separated via water based extraction processes. In fact, only 20% of oil sands reserves are recoverable by surface mining. The remaining 80% occur deeper under the surface where in-situ (drillable) methods are used to extract the bitumen. Both processes are extremely energy intensive, using up vast amounts of Canada’s domestic natural gas supply.

2 tons of earth and sand are excavated to make one barrel of bitumen.

Bitumen extraction by surface mining consists of the following stages:

• Extraction
• Separation
• Upgrading
• Refining 

Oil sands extraction (East Explorer, 2011)

In-situ extraction includes the following techniques:

• Steam Assisted Gravity Drainage (SAGD)
• Cyclic Steam Stimulation (CSS)
• Vapour Recovery Extraction (VAPEX) 
• Toe-to-heel Air Injection (THAI) 

Tar sands extraction by Steam Assisted Gravity Drainage (OSDG, 2009)

SAGD and CSS are the most tried and tested techniques in current in-situ operations. Both processes require large amounts of water and energy to inject steam into the bituminous reservoir and pump the liquefied bitumen up to the surface. The in-situ infrastructure typically disturbs about 5% of the total land surface through seismic and directional drilling, in spite of this the planned expansion of in-situ operations will turn a quarter of Alberta’s boreal forest into a large industrialised zone.

The recovery of mineable reserves has been the real driving force of Alberta’s oil sands industry to date. In fact, around 68% of the remaining proven mining reserves are currently in development (compared to a mere 3% of deep tar sands). Recent improvements in in-situ extraction methods, however, have significantly reduced production costs and made them more competitive with strip mining (Brown, 2002). New technologies are still required to access approximately two-thirds of the total deposits, which are either too deep for surface mining or too shallow for steam injection (Czarnecki et al, 2005).

Environmental challenges

Due to the heavy environmental footprint of tar sands extraction (accounting for 5% of Canada’s total GHG emissions), the Canadian government has devoted over C$6 billion to various climate change programmes in the last 15 years, spending C$2 billion alone on carbon capture and storage (CCS). Bitumen upgrading continues to be the most carbon intensive process in the oil sands production, followed by SAGD and strip mining.

Each barrel of bitumen produces 3 times more GHG emissions than a barrel of conventional oil.

Major environmental risks associated with the tar sands extraction:

• Surface disturbance 
• Air contamination 
• Water contamination, including tailings ponds 

Mineable oil sands cover approximately 0.1% (4,802 km2) of Canada’s boreal landscape. Of that, 530 km2 has been decimated due to strip mining (Kelly at al, 2010), but it is expected that forthcoming mining operations will disturb a total of 3400 km2 of boreal forest. Only 67 km2 of land has been reclaimed so far.

The process of bitumen upgrading is responsible for the highest proportion of airborne emissions (Kelly et al, 2010). A ten-year evaluation of ambient air quality in Alberta’s oil sands region (Kindzierski, 2011) revealed small, steadily increasing concentration of nitrogen dioxide (NO2) at Fort McMurray and Fort McKay.

3 barrels of fresh water are needed to produce a barrel of bitumen.

According to Nikiforuk (2008), bitumen is the most water-intensive oil product. The Athabasca River, regarded as the world’s third largest watershed, is key to bitumen separation. Tailings ponds, build on the upstream of Athabasca River, receive large quantities of wastewater from the separation process. An average tailings pond will leak around 65 l/s of toxic contaminants such as polycyclic aromatic hydrocarbons (PAHs), naphthenic acids (NAs), arsenic and mercury to the river system.

Syncrude’s tailings pond holds 540 million m3 of wastewater and can be observed from space.

Research conducted by Timoney (2007) found high concentrations of arsenic, mercury, and PAHs downstream of the tar sands facilities. The First Nations people at Fort Chipewyan on the Athabasca River Delta have therefore been exposed to higher levels of riverborne contaminants than upstream communities, causing frequent incidents of colon and prostrate cancers and adverse ecological impacts on aquatic life (i.e. high mercury accumulation in fish). Both Timoney (2007) and Kelly et al (2010) perceived a lack of industry and government accountability for a long-term air and water contamination monitoring of the Athabasca River watershed.

As the largest industrialised project of its kind, the tar sands operation in Alberta is the foundation of Canada’s prosperity and economic growth. Despite their heavy carbon footprint and an increasingly detrimental impact on the local environment and indigenous communities, one wouldn't be too foolish to assume that the Canadian tar sands are just the ticket for the U.S. energy security - unless, of course, the President’s final decision is preceded by a miraculous 'rethink of our current energy trajectory'.

References

1. Alberta Energy (2011) Oil Sands: Facts and Statistics. Alberta Energy.
2. Brown, C.E. (2002) World Energy Resources: International Geohydroscience and Energy Research Institute. Berlin: Springer. 
3. Canadian Association of Petroleum Producers (CAPP) (2011) Crude Oil: Forecast, Markets & Pipelines. CAPP, 2011-0010. 
4. Clarke, T. (2008) Tar sands showdown: Canada and the new politics of oil in an age of climate change. Toronto: J. Lorimer & Co. 
5. Czarnecki, J. et al. (2005) On the nature of Athabasca Oil Sands. Advances in Colloid and Interface Science, 114-115, pp. 53-60. 
6. Kelly, E.N. et al. (2010) Oils sands development contributes elements toxic at low concentrations to the Athabasca River and its tributaries. PNAS, 107 (37), pp. 16178-16183. 
7. Kindzierski, W.B. (2011) Ten-Year Trends in Regional Air Quality for Criteria Pollutants in the Athabasca Oil Sands Region. Edmonton, Alberta: Department of Public Health Sciences. 
8. Laxer, G. and Dillon, J. (2008) Over a Barrel: Exiting from NAFTA’s Proportionality Clause. Parkland Institute and Canadian Centre for Policy Alternatives (CCPA). 
9. Nikiforuk, A. (2008) Tar Sands: Dirty Oil and the Future of a Continent. Vancouver BC, Canada: Greystone Books/David Suzuki Foundation. 
10. Sinclair, S. (2011) Briefing paper: Tar Sands and the CETA. Ottawa ON, Canada: Canadian Centre for Policy Alternatives (CCPA).
11. Timoney K.P. (2007) A Study of Water and Sediment Quality as Related to Public Health Issues, Fort Chipewyan, Alberta. Fort Chipewyan, AB: Nunee Health Board Society. 
12. TransCanada Corporation (2011) Keystone Pipeline Project. TransCanada Corporation.