We have implemented strategies to reduce our use of fresh water at our Long Lake oil sands facility.
Improving Water Management at Long Lake
At Long Lake, Nexen uses steam assisted gravity drainage (SAGD) to extract bitumen from the oil sands reservoir. The SAGD process involves injecting steam into the ground, which enables the bitumen contained within the sand (and which is later upgraded into oil) to be heated and released. The resulting water and bitumen is pumped back to the surface where the water is separated and treated before it is recycled and reprocessed back into steam and then re-injected into the reservoir. While this recycling process reduces our need for water, we still require about three million cubic meters of water per year.
Nexen is committed to reduce the amount of water we use in all our operations. We have improved our efforts to track, quantify and manage the water we use at Long Lake, and continue to work to improve our water recycle rate.
Improving Water Management in Drilling in the Oil Sands
In the 2013-2014 oil sands drilling program, Nexen was able to reduce our water used in drilling by almost half. Drilling fluids are processed through centrifuges which separate the fluids from the solids. During the drilling process below the fresh water protection zone we attempt to utilize as much strip water as possible, thus decreasing the quantity of fresh water utilized for mixing batches of drilling fluids.