Cenovus’s patented blowdown boiler technology enables us to reuse a greater percentage of the water we use to generate steam at our oil sands operations. In our SAGD operations, salty, undrinkable water from deep aquifers is treated then heated to create steam, which is injected underground to soften the oil so it can flow enough to be pumped to the surface. The vast majority of the water that returns to the surface from this production process is recycled and reused over and over again to generate more steam.
The steam is created by a steam generator, which typically converts about 80 percent of the water it receives into steam. The remaining 20 percent is disposed of due to the solids left behind. We challenged an industry belief that the leftover water could only be reused if it was treated, which adds cost and uses energy. We developed a process to re-boil the leftover water without treatment. This second boiler – the blowdown boiler – converts the majority of the waste water into steam.
Overall, over 90 percent of the original input water can now be converted into steam and we can reduce our demand for make-up water by over 50 percent, meaning we draw much less water from nearby aquifers.
We successfully commercialized our blowdown boiler technology at Foster Creek in 2011 and are planning on including it as part of our planned Foster Creek expansions. We’re also identifying opportunities to use blowdown boiler technology at our other oil sands facilities.