We plan and design our operations to minimize fresh water use, monitor and track all water usage and disposal, as well as measure the amount of water recycled, processed and stored. We continue to work to find ways to increase water use efficiency across all our business units.
At our Primrose/Wolf Lake (PAW) thermal operations, 57 per cent of the water we use to generate steam is brackish. Our ongoing reduction of fresh water use is being accomplished through a long-term brackish (saline) water source development plan, including associated brackish wells, field and plant infrastructures. Efforts to improve fresh water use efficiency at PAW have resulted in a 50 per cent decrease of fresh water use per barrel of bitumen production since 2008.
In Southeast Saskatchewan and Manitoba, we use water from a brackish aquifer for waterflooding purposes in our enhanced oil recovery (EOR) operations.
We also treat and use brackish water at our Pelican Lake area, where we have pioneered polymerflooding for enhanced oil recovery. As a result of infrastructure investments made in 2013 at our Pelican Lake operation, we achieved a water recycle rate of 94.9 per cent; and our Nipisi light oil waterflood operation achieved a water recycle rate of 99.8 per cent.
Our Horizon Oil Sands operation is designed to recycle over 80 per cent of the water used in bitumen extraction so that it can be reused in our processes. We limit our fresh water use by withdrawing less than one-third of our regulated allocation from the Athabasca River. We work with other oil sands operators to manage water withdrawals to ensure the ecology of the Athabasca River is protected. Horizon features an on-site water storage pond that holds enough water for up to 30 days that allows us to maintain production in the event of water withdrawal restrictions during the river's low flow periods. Additionally, a new water treatment plant at Horizon that is currently in the engineering design stage will further reduce our fresh water consumption. More information on our Basal Water Treatment project can be found here.
Canadian Natural’s Septimus unconventional natural gas operations in northeast British Columbia also utilizes produced water from the plant for fracturing operations and recycles water to drill subsequent wells.