Solvent Based Gravity Drainage for SAGD Applications

N- Solv Corporation


Project Type

Demonstration

Project Value

$83,000,000

Project Status

Completed

Location

Fort McMurray, AB

Funding Amount

$10,000,000

Extracting Bitumen with a More Sustainable Process

Nsolv is a water-free, in-situ bitumen extraction technology that is a potential solution for sustainable and continued oil sands development. Funded through Round 4: Carbon Capture plus Energy Technology, this Nsolv pilot project aimed to advance the technology to reach commercial readiness.

Nsolv is an in-situ extraction process similar to steam assisted gravity drainage (SAGD) but uses solvents such as propane or butane at temperatures around 40 degrees Celsius instead of steam at around 230 degrees Celsius. The solvent is warmed and injected into the reservoir and liberates the bitumen, which is pumped to the surface. The solvent is returned to the surface with the bitumen, where it is separated and recycled into the reservoir. This process reduces GHG emissions by 70 to 80 per cent compared to the SAGD process. This is because Nsolv avoids direct and indirect stationary combustion emissions by replacing high temperature steam with lower temperature solvent. Heating the solvent to moderate temperatures is more efficient than steam at reducing bitumen viscosity enough to enable gravity drainage.

Understanding Solvent Choices for Specific Reservoirs

The project was completed in 2015 and produced valuable experience through the engineering, construction, commission and operating phases that will allow Nsolv to build a better, more efficient and stable operating plant for all future projects. Notably, the project found the choice of solvent is contingent upon the reservoir selected for the project. While the pilot project was designed to run on either propane or butane, the reservoir turned out to be shallow and could only support lower pressure, butane operation. This is because at the pilot site, an ideal operational temperature range was between 40 and 60 degrees Celsius as extraction rates were sufficiently high above 40 degrees Celsius and the solvent to oil ratio was sufficiently low below 60 degrees Celsius. Butane has a bubble point within that ideal temperature range, whereas propane has a bubble point of only 40 degrees Celsius.

What’s next?

Nsolv patented its technology for in-situ projects and was recognized at the 2016 Global Petroleum Show Awards, receiving the Innovation in Technologies Award. While oilsands companies have continued to advance commercial implementation of solvents, this particular approach has experienced limited commercialization to date.