SAGD Produced Water Evaporator
GE’s SAGD Produced Water Evaporators enable the enhanced oil-recovery technique known as steam-assisted gravity drainage (SAGD). Falling film evaporators powered by mechanical vapor compression convert brackish water to boiler feed water. Steam is then generated and injected underground liquefying the heavy oil, which is pumped to the surface.
Environmental Benefit
Compared to the traditional chemical water treatment approach used in once-through steam generators for heavy oil recovery, GE’s SAGD Produced Water Evaporator is designed to reduce total water consumption by approximately 50 percent. GE’s SAGD Produced Water Evaporators also generate less wastewater and use less chemicals than the traditional approach.
Operating Benefit
GE’s SAGD Produced Water Evaporators produce high-quality steam, thus enabling the use of drum boilers. Additionally, they de-couple the water treatment system from the boiler feed system, increasing boiler reliability.
The environmental challenge
In recent years, SAGD has rapidly emerged as the leading technique for extracting bitumen from the Canadian oil sands and elsewhere around the world. A key challenge has been how to generate the required high-quality steam using less water while managing environmental impact.
The Connacher Great Divide Oil Sands Partnership selected GE’s SAGD Produced Water Evaporators to dramatically reduce the amount of water used at its Algar Oil Sands Project in Alberta, Canada and to help protect regional water resources.
GE’s innovative solution
GE’s SAGD Produced Water Evaporator employs vertical tube falling film evaporation technology. Due to the very high water quality produced by the evaporators, the evaporative approach allows for the use of standard or 'packaged' drum boilers in lieu of once-through steam generators (OTSGs) for steam generation. Producers inject the high-quality steam directly underground where its heat liquefies the thick bitumen deposits so they can be pumped to the surface.
Environmental impact
Compared to the traditional chemical water treatment approach used in once-through steam generators for heavy oil recovery, GE’s SAGD Produced Water Evaporator is designed to reduce total water consumption by approximately 50 percent. Customers will save around a third of a barrel of water for each barrel of bitumen produced. At a 70,000 barrel per day oil production facility, this is a savings of 1 MM gallons of water per day.
Furthermore, because GE’s SAGD Produced Water Evaporator can use brackish water, it is designed to help GE customers significantly reduce or eliminate the need to draw fresh water from lakes, rivers or aquifers for the SAGD steam generation processes.
Cutting costs
Compared to the traditional chemical water treatment approach used in once-through steam generators for heavy oil recovery, GE’s SAGD Produced Water Evaporator is designed to reduce the volume of wastewater disposal by approximately 90 percent. This will save customers approximately $.14/bbl of oil produced or $10,000 per day for a 70,000 barrel per day facility, assuming a deep well injection cost of $2.10 metric tons of wastewater.
