Water

Canadians are custodians of the most significant reservoirs of fresh water in the world. Annually, 9 per cent of the world's renewable water supply flows from Canadian rivers. Lakes cover 7.6 per cent of the Canadian landmass, wetlands 14 per cent and perennial snow and ice 2 per cent. The Great Lakes, with about 20 per cent of the world's fresh surface water, make up the largest freshwater lake system in the world.

Canada has rigid regulations with respect to the use of water for industrial purposes and the disposal of water from processing plants or oil and gas production. Water for industrial use may not be removed from wells, streams or other water bodies without approval of the responsible regulatory authority. This process water must be treated and returned to the natural environment.

In Alberta, the main uses of ground water are: waterflood injection for enhanced oil recovery, municipal water supplies, and non-irrigation agricultural use. The oil and gas industry received approximately 9.3 per cent of all surface water licenses in 2010. Under the government's "Alberta's Water Conservation and Allocation Policy for Oilfield Injection" all applicants are required to evaluate alternative sources of water before applying for a fresh water license.

All water produced from oil and gas wells must be returned to the underground zone of origin, or to another zone approved by the regulatory authority. Water discharged from processing facilities must be treated and disposed of into an approved underground formation, or conditioned to rigid standards before being discharged to a stream or other surface water body.

Water is essential for the conversion of oil sands into a variety of oil products Currently about 2.5 cubic metres of fresh water per cubic metre of oil produced is used by mining operations and 0.5 cubic metres for in-situ operations. As extraction operations mature, water use is expected to be reduced to two cubic metres per cubic metre of product.

Although oil sands operations have minimized their water use (projects recycle 80 to 95 per cent of water used), attempts have been made at further reductions:

• Apache and Encana - Horne River project - have decreased their use of surface water, securing access to an integrated water treatment and distribution system, which allows for the full recovery and re-use of fracture stimulation fluids
• Devon Energy - Jackfish project - was the first SAGD installation to rely completely on brackish or non-portable water for steam generation.
• Suncor Energy - Firebag thermal project - uses water from its mining tailings ponds as supply for steam generation.
• In surface mining operations, operators are attempting to increase the recycle component by improving equipment design to utilize and treat poorer quality water; accelerate consolidation of tailings to release water back into the cycle; use more air cooling; and minimize operating inventories.
• In in-situ operations, the aim is to improve water use through: water treatment; greater use of brackish and saline water including testing desalination technologies; reducing water use through the addition of solvents to decrease bitumen viscosity and improve oil displacement; improvements in the steam-to-oil ratio through improved reservoir modeling and well placement; and pursuit of new no-water technologies.

Driving forces in the development of technologies to increase water use efficiency are:

• Public concern about potable water availability and contamination; conservation of natural ecosystems, and keeping water withdrawals to prescribed limits to maintain natural fluctuations in rivers and lakes.
• Industry's desire to minimize water use so as to reduce operating costs related to water handling and storage.

Water - Resource Center