The most common method of in situ oil sands production is called steam assisted gravity drainage (SAGD). In this technique, two parallel wells are drilled horizontally into the reservoir from a central well pad. Steam generated from a surface plant is pumped into the reservoir through the top well, causing the bitumen to soften and flow to the bottom of the chamber. The bitumen is then pumped to the surface from the producing (bottom) well.
Bitumen gets pumped to the surface along with water as an oil and condensed steam emulsion. This stream is separated and treated, before the water is recycled for generation of new steam. Operators recycle as much of the water for steam production as possible, but treatment of water to produce high quality boiler feed water (for steam production) can be challenging.
In 2013, Alberta Innovates, GE and Suncor began piloting new produced water treatment technologies to treat, and thus reuse, more water using less energy and fewer pieces of equipment. Benefits of the pilot may include lower costs for water treatment processes, lower GHG emissions and decreased process footprint of SAGD facilities.
In early 2014, additional participants were added through a COSIA joint industry project (JIP). This helped extend the pilot testing phases to obtain more data, and to allow for additional laboratory-scale testing to further refine the processes involved in the pilot. Extending the project to COSIA members may allow potential improvements to be shared across the oil sands sector. In 2015 water treatment membranes were tested at Suncor’s MacKay River facility. Phase 2 development work progressed throughout 2016, and the final phase of pilot testing onsite is anticipated to occur in late 2017.
“This pilot is an advancement of work that Suncor began with GE in 2011 at our MacKay River SAGD facility,” says Mick McGregor, Suncor’s Senior Development Engineer, Upstream. “Development of enhanced produced water treatment technologies should enable our facilities to treat and reuse water more efficiently, which in turn could result in improved plant operation and lower energy usage.”
The JIP will enable testing of multiple technologies and various chemistries to develop more robust treatment processes for in situ oil sands operators.
Process upsets within traditional de-oiling and water treatment processes can make it difficult to consistently treat produced water. For example, oil passing through water treatment units can result in steam generator issues, failures in boiler tubes and an overall reduction in plant availability, reliability and maintainability. This can lead to higher GHG emissions.
The approach being piloted is designed to provide a physical barrier to oil, and also remove dissolved organics and hydrocarbons. This would effectively create a barrier to oil from passing further into the produced water treatment process and ultimately the steam generation units, increasing the efficiency of the plant.
“GE screened and selected the best available water treatment technologies for testing,” says Mick. “Suncor joined the pilot program with Alberta Innovates and GE in 2011 as an industry partner to provide input on the pilot facility design, definition of the pilot test plan, and provide hot-connected access for the pilot facility at our MacKay River SAGD facility.”
The current processes being tested in the expanded COSIA JIP are housed in two containers with external storage facilities. An additional container was installed in 2015 at the end of Phase 1 testing to allow for Phase 2 testing to occur in 2016. One benefit of the pilot’s design is it will be simple to relocate and modify equipment to suit other testing sites once the pilot is completed at MacKay River.
Improvements in operations and reliability mean less water is wasted and GHG emissions are reduced.
GE’s work on the pilot so far suggests that oil sands producers could see significant reductions in the amount of energy required to make steam, as well as GHG, capital and operating cost reductions.
“The technologies being tested in this pilot are expected to have economic benefits for in situ production, and continue the work of the Water Environmental Priority Area (EPA) members to achieve their goal, to reduce fresh water use intensity by 50 percent by 2022,” says John Brogly, COSIA’s Director of Water and Tailings EPAs.
The results of the pilot will be reviewed by Suncor, COSIA JIP participants ConocoPhillips and Devon Canada as well as COSIA Associate Member participants Alberta Innovates and GE. Key environmental improvements from the project may be contributed to COSIA in order to share those improvements with the members of the Water EPA.
The project was developed by Suncor and GE prior to the formation of COSIA, but it has been able to evolve through collaboration with additional COSIA participants.
“The member companies of COSIA have significant industry experience to guide a project like this in the correct direction,” explains Mick. “Many ideas seem successful on paper, but it takes focused guidance and perseverance to prove new technology to the industry. Having COSIA and GE assist brings significantly more robustness and value in moving new technologies from the laboratory into reality.”
Sharing pilot costs among multiple partners have allowed for an increased scope to the project and, if the technology proves successful, should enable potential reduction in capital and operational costs.