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Indicator Type: Environmental Pressure
To get the greatest amount of oil out of the ground, water is sometimes pumped into an oilfield. This causes more oil to move toward producing wells. This process, which is called oilfield injection, also helps to keep pressure high enough in the oil pool to maintain production. Either groundwater, both saline and non-saline, or surface water from rivers or lakes can be used for injection.
This indicator depicts the use of water over time for oilfield injection purposes. Three types of source water (surface water, non-saline groundwater, and saline groundwater) are identified separately as solid color lines. The totals are shown as dashed black and grey lines.
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Trend: Decreasing reliance on non-saline and fresh water
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What does the indicator show?
Fresh surface water and "fresh" (referred to as non-saline) groundwater have typically been used for conventional oil recovery schemes. Use of fresh water sources for this purpose has been gradually declining as fewer conventional oil pools remain to be developed. The oil industry has also improved water efficiencies and recycling. This means that process improvements are reducing the amount of water required to produce a barrel of oil. Non-saline groundwater use has remained relatively consistent over time, while saline groundwater use is increasing as the demand for thermal oil sands recovery is growing. Older thermal recovery schemes have typically relied on a combination of fresh surface water and non-saline groundwater supplies for their source waters. In recent years, most new projects have attempted to use more saline groundwater. Overall water use has been fairly steady for the last 20 years, and the reliance on fresh sources has been declining. In the past couple years, more than 35% of source water used for oil recovery was saline groundwater, up from only 10% just 15 years ago.
View a graph of the relative proportions of
fresh and saline waters used for oilfield injection.
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Why is this indicator important?
Most uses of water result in some amount that is not returned back to the local ecosystem. With oilfield injection, injected water mixes water that occurs naturally in oil reservoirs, and the saline mix is re-injected many times. However, the water that is injected into an oilfield is ultimately no longer readily available for other beneficial uses. Although oilfield injection is not the largest use of water in Alberta, Albertans have expressed concern over the use of water that removes it from the active hydrologic cycle. The concerns were particularly strong in recent years when many parts of Alberta had been experiencing drought conditions. Furthermore, projections indicate that use of water for oil recovery could increase significantly in the future. This indicator will track the use of water for oilfield injection over time. The purpose is to assess whether conservation, improved efficiencies, and technological changes are resulting in less reliance on fresh water sources, and water in general.
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What actions are being taken?
Following the consultations for Alberta's Water for Life Strategy, Alberta Environment commissioned a report to determine actual water use for oilfield injection purposes in Alberta. The Advisory Committee on Water Use Practice and Policy was created to examine how this use of water should be addressed into the future. Recommendations from the advisory committee are being used to create policies that reflect the priorities of Albertans with respect to these uses.
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Links to additional information
How oil and gas is recovered (Canadian Association of Petroleum Producers): http://www.capp.ca/default.asp?V_DOC_ID=33
Report of the Advisory Committee on Water Use Practice and Policy : http://www.waterforlife.gov.ab.ca/docs/Final_Recommend_Online.pdf
Water and Oil: An Overview of the Use of Water for Enhanced
Oil Recovery in Alberta: http://www.waterforlife.gov.ab.ca/docs/water_oil_info_booklet.pdf
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