Using Saline Water Sources

The Water Act defines saline water as water that contains over 4,000 parts per million of total dissolved solids. Total dissolved solids are inorganic salts such as calcium, potassium, chlorides and sulphates and small amounts of organic matter that are dissolved in water. Water with less than 4,000 parts per million of total dissolved solids is considered fresh, even though it may be brackish and non-potable. To put this into perspective, the Canadian Drinking Water Quality Guidelines recommend water contains less than 500 parts per million total dissolved solids for potable use.

A joint Energy Resources Conservation Board and Alberta Environment draft water directive released in February 2009, called Requirements for Water Measurement, Reporting and Use for Thermal In-Situ Oil Sands Schemes, is under review by various stakeholders. Among other water measures, the directive requires producers to use less freshwater (water with less than 4,000 parts per million total dissolved solids) in their operations. There is a growing expectation in Alberta regulation to reduce reliance on freshwater. In-situ operators, including ConocoPhillips Canada, explore for saline water sources and design facilities to permit substitution of saline water for fresh.

Using water with elevated salinity poses additional challenges in terms of exploration, development, transport and treatment. Water with elevated salinity requires more intensive treatment and generates additional volumes of waste water. It is more energy intensive to transport, treat and dispose of higher salinity water, which may lead to increased greenhouse gas production and cost. We are exploring new methods, such as advanced membrane technology, to meet the technical challenges posed by using this water.

Surmont Phase 1 was designed and constructed before these regulatory changes and uses non-potable non-saline water for steam generation. The water source is the Lower Grand Rapids, which contains non-saline, non-potable water between 1,200 and 2,500 parts per million total dissolved solids and is classified as freshwater under the Water Act. We are developing plans to incorporate saline water use at Phase 1, though we will need to use a nominal volume of freshwater as makeup water. Surmont Phase 2 is designed to handle saline water as a primary source water-feed. We anticipate the Surmont project will meet the emerging regulatory requirements when both phases of Surmont are online. Maximizing the use of saline water and meeting the shortfall with freshwater will result in a significant reduction of freshwater makeup over the life of the project.

Over the past few years, we explored saline water sources to meet our needs for future phases. Since 2007, we have spent approximately $26.5 million and drilled approximately 19 wells as far as 60 kilometres from our facilities. This effort has identified a saline source east of Surmont that has potentially both the volume and an appropriate level of salinity for Phases 1 and 2. Additionally, we have revised our saline well delineation strategy to target saline sources with lower total dissolved solids levels. We also increased the diameter of our saline source water pipeline from 12 to 16 inches, which enables us to accommodate larger water volumes.

Other operators in this area are also seeking saline water sources and designing their facilities to handle this water. This will result in competition for water, making increased recycle rates, water-use efficiency and regional approaches to water management even more important in years to come.