Tar Sands Facts:
The technical term for the oil extracted from tar sands is crude bitumen, which is defined as a viscous (thick), heavy oil that will not flow to a well in its natural state.
Crude bitumen is extracted from the mined tar sands through a process that mixes the tar sands with hot water to separate the bitumen from the sand.
Preparing to Strip Mine the Tar Sands:
1. All wetlands need to be drained
2. All rivers in the mine site have to be diverted
3. All trees and vegetation stripped from the surface.
Currently over 2,800 square kilometers has been identified as surface mineable zone within the Athabasca deposit.
Removing the Tar Sands – Strip Mining Process
It takes approximately two tons of tar sands along with another two tones of overburden (containing soil, sand, clay and rock) to yield one barrel of oil.
Hydraulic shovels are used to tear into the earth and were exculsively manufactured for this purpose – they are the largest in the world. Every scoop of these shovels digs out over 40 cubic meters of material.
Within 48 hours of mining operations enough tar sands are removed to fill Toronto’s Skydome or New York’s Yankee Stadium.
Tar sands deposits are composed of sand, silt, clay, water and about 10%-12% bitumen.
Tar sands mining trucks used to move the material from the mine site to the preparation facilities are 15 metres long by 7 metres tall, have 4-metre tall tires and are 40% heavier than a Boeing 747 airplane.
Extracting a barrel of bitumen using surface mining requires:
• Two to five barrels of fresh water (a barrel can hold 159 litres, a little more than an average bathtub)
• 250 cubic feet of natural gas,66 enough to heat a Canadian home for almost 1.5 days.
• The mining and extraction process recovers about 90% of the bitumen found in the deposit.
In-situ Extraction of Tar Sands
To remove the bitumen from a depth of more than 100 meters an injection of high pressure steam is pumped into the earth to allow the bitumen to reduce its thickness and pump it up in return pipelines. This process is refered to as Steam Assited Gravity Drainage.
Well pads are constructed in an area up to 150 square-kilometer area and are connected with a series of above ground pipelines.
All vegetation has to be cleared to make way for multiple pairs (injector and producer) of horizontal wells.
A central water or steam producing facility is connected to these well pads with miles of above ground piping.
The water and bitumen are returned to the central facility by another above-ground pipeline, which separates the bitumen from the water and recycles the water to produce more steam.
Extracting a barrel of bitumen using SAGD technology requires
• 2.5 to 4 cubic metres of steam to produce 1 cubic metre of bitumen
• 1000 cubic feet of natural gas, enough to heat a Canadian home for about 5.5 days
The SAGD process recovers between 60%-80% of the bitumen found in the geological formation.
Two stages of upgrading are required to produce the final synthetic crude oil from bitumen.
The first stage reduces the large bitumen hydrocarbons into smaller molecules by coking (vaporizing) or hydrocraking (use of hydrogen and a catalyst of platinum) — sometimes both methods are required.
The second stage of upgrading is called hydrotreating whereby high pressure and temperatures (300-400°C) are used to remove nitrogen and sulphur.
About 65% of the bitumen is upgraded in Alberta to form light, sweet synthetic crude oil. The remainder is transported by pipeline to other regions of Canada and the United States for upgrading.
One barrel of synthetic crude oil produces enough gasoline to fill three-quarters of a Chevy Avalanche’s gas tank, or enough to drive it about 490 kilometres.
The upgrading plants are massive complexes that take years to build and require more boreal forrest be destroyed to make room for the huge footprint of the plant and miles of supply roads.
Only about 10% of the tar sands are actually oil. Therefore, vast quantities have to be mined to produce one barrel of oil.
TAR SANDS RECLAMATION
Tar sands mining represents the most intensive and environmentally damaging method of oil extraction in Alberta, involving the drastic alteration of surface and subsurface materials.
Very little area directly affected by mining operations has been restored to land with equivalent capability to the pre-mined land, and after 40 years of
mining no operations have received a reclamation certificate.
Suncor states that it has reclaimed 858 hectares of land since it started operations in 1967, less than 9% of its total land disturbed to date.
Syncrude’s operations have disturbed 18,653 hectares, with 4,055 hectares of land reclaimed.
In response to growing criticism, the industry has adopted what it refers to as “progressive reclamation,” which aims to reclaim land as quickly as is
technically possible.
However, even with progressive reclamation, virtually no reclamation is undertaken for the first 20-30 years of a project.
THREATS TO WOODLAND CARIBOU
Woodland caribou have been designated as “threatened” under Alberta’s Wildlife Act and the federal Species at Risk Act (SARA).
They are extremely sensitive to disturbance and stay well back from clearings such as roads, seismic lines and well sites.
The combination of forestry, oil and gas, and tar sands development is continually shrinking the areas of effective habitat that can support viable
populations.
Cleared paths such as seismic lines have made it far easier for hunters as well as wolves and other predators to access areas where the caribou are located.
Environment Canada has noted that clearing in the boreal forest for seismic exploration by the oil and gas industry, including the tar sands industry, equals or exceeds the amount removed by the forest industry each year.
THE TAR SANDS IN PERSPECTIVE
Existing, approved and currently planned tar sands mines and in situ projects in the region will directly impact more than 2000 square kilometres of
boreal forest. This is:
• Approximately 28,465 NFL football fields.
• Approximately 2.5 times larger than Calgary and 3 times larger than Edmonton
• More than 5 times the size of Denver.
• Almost the size of Tokyo – home to 12 million people.