25 September 2020
GERI pilots cost-saving DCSG in Canada’s oil sands
The technology developer hopes its portable steam generator can breathe new life into projects that have reached the final stages of development.
Earlier this month, General Energy Recovery Inc (GERI) completed a multi-week commercial pilot with its portable direct-contact steam generator (DCSG) at a steam-assisted gravity drainage (SAGD) oil sands development operated by a large producer in the Lloydminster area. The aim of the pilot was to improve oil recovery at minimal cost and with a smaller environmental impact. GERI is now awaiting the results and is in discussions with two other operators regarding field tests with the DCSG.
The company’s CTO, Brian Kay, believes the technology could be a boon for the oil sands, where projects are breaking even if not losing money due to the double hit dealt by local regulatory issues and the current oil price downturn. He explained to WiO that the company’s DCSG is more economical than conventional steaming operations due to having a better steam-to-oil ratio (SOR), requiring lower energy input and using less water.
Typical SAGD SORs are 2.5-3:1, but GERI’s system has a SOR of 0.58:1. This is due in part to the fact that the combustion process generates about 13% free water, adding to the economics and environmental sustainability of SAGD projects. The combustion process also produces nitrogen and carbon dioxide, which are injected into the reservoir along with the steam (see diagrams). While the steam heats the reservoir and reduces oil viscosity, the exhaust gases repressurize the reservoir, allowing for increased oil recovery.
Because exhaust gases may disrupt the steam chamber and/or overpressurize the reservoir, GERI’s technology may not be suited to new or mid-life SAGD assets. However, the technology is expected to be particularly useful for late-life projects to recover additional reserves that would have otherwise been considered uneconomical.
“There's a great belief that we could add three to five years to the life of a SAGD project,” Kay said. “Canada is fairly far advanced with some of the SAGD projects and some of them are nearing or at the end of their lives, so in the next year or two, we are looking to develop our technology for those applications.”
Whereas typical steam generators require demineralized water, GERI’s DCSG can handle feedwater with up to 300 ppm of total dissolved solids (TDS). Levels above that would necessitate very basic reverse osmosis pretreatment to prevent clogging the steam generator.
“Even if our system did hit very high-TDS water, repair and replacement would be extremely cheap compared to conventional systems,” Kay told WiO. He explained that meanwhile, it could cost around $1 million to de-clog or replace tubes in a conventional 50 million Btu/hour steam generator.
GERI is continuing to optimize its offering and as part of its late-2020/2021 program, the company is working to eliminate the presence of precipitated solids downstream of the generator to prevent the possibility of plugging up the reservoir. Doing so would enable the DCGS to take even poorer quality water.
Additionally, GERI’s DCSG is highly portable and requires only about three days to set up or break down. Kay says these characteristics appeal to “oil sands operators that want to test a concept or an area without spending $50 million to develop and put in a steam plant.”
GERI is eager to deploy its steam generator for new oil sands clients under a service model based on either a daily rate or a fee per gigajoules (GJ) injected. Previous projects have cost $100/GJ with injection rates up to 200 GJ; however, costs will decrease as GERI approaches full commerciality and is able to take advantage of economies of scale.
The company is also eyeing opportunities abroad, given the difficulties that Canada’s oil & gas industry is currently facing.
“We are looking strongly to international markets and we have made some tentative inroads into the US,” Kay said, noting that GERI prefers reservoirs to be at a depth of least 500 feet to prevent the exhaust gases from migrating to the surface.