Using Non-Condensable Gas to reduce SAGD Emissions
Funded through ERA Call #3: Industrial Efficiency, this project successfully reduced energy intensity in Steam Assisted Gravity Drainage (SAGD) oilsands operations using Non-Condensable Gas (NCG) co-injection. The project provided insights affirming NCG co-injection as an effective efficiency improvement technology and providing guidance for future projects aiming to enhance the sustainability of SAGD operations.
In SAGD, steam is typically injected to create a steam chamber, mobilizing heavy oil for production. Over time, energy inefficiencies arise due to increased heat losses and declining reservoir performance. To decrease these issues, non-condensable gas (such as methane) can be injected alongside steam into the reservoir. Whereas steam condenses, creating voids, NCG fills the voids left by drained oil and condensed steam while maintaining reservoir pressure. The NCG injection replaces part of the steam requirement, reducing heat loss as well as water and fuel gas consumption while maintaining oil production levels. Additionally, by reducing the need for steam, the process also directly reduces emissions associated with fuel combustion to generate steam. The implementation of this technology from June 2019 to March 2020 resulted in a 25 per cent reduction in the steam-to-oil ratio (SOR) which reduced emissions by approximately 32,500 tonnes.
NCG as a Retrofit Solution
The Athabasca Oil Corporation’s NCG co-injection project yielded several valuable lessons about the feasibility and effectiveness of the technology. The project showed NCG can be successfully injected with modifications to existing SAGD facilities, demonstrating its potential as a practical retrofit solution for reducing the energy intensity of mature wells. However, reservoir-specific conditions must be considered for optimal implementation. Additionally, NCG co-injection effectively reduced SOR by 25 per cent as previously mentioned. This reduction surpassed the initial target of 10 per cent, confirming its capability to significantly lower energy demands and emissions.
What’s next? Since this project’s completion in 2018, NCG co-injection technology has seen significant adoption and development in Alberta’s oilsands. The technology has transitioned from pilot projects to widespread application, supported by advances in modeling and infrastructure optimization. Currently, it is now used in several commercial-scale operations and is particularly effective in addressing efficiency losses in SAGD reservoirs