An Alternative Process to Conventional Oil Sands Mining
Canadian Natural has developed the In Pit Extraction Process (IPEP) as an innovative alternative to conventional oil sands slurry preparation, bitumen extraction, and tailings handling. Funded through ERA #2: Oilsands Innovation in 2017, this project demonstrated commercial feasibility by achieving continuous 24-hour all-season operation at the target ore feed rate.
The IPEP was proposed as a way to significantly reduce the storage of fluid in tailings ponds, handling the solids only once while also reducing the associated cost, environmental impact, and liabilities. It was also intended to reduce the distance the waste material is transported, resulting in less energy and therefore less greenhouse gas (GHG) emissions. The IPEP technology involves a relocatable, modular extraction plant that can be moved as the mine face advances. Ore processing and bitumen separation occurs adjacent to mining operations, significantly reducing material transportation. In addition to reducing GHG emissions, IPEP produces stackable tailings within the mine pit, reducing the volume of fluid tailings, reducing methane emissions from tailings, and accelerating reclamation of oil sands mines. IPEP also uses equipment of a type and size that are commercially available and currently used in the mining sector or other industries. There is a significant reduction in capital cost with mobile equipment compared to the high sustaining capital cost of relocating and constructing a traditional ore preparation plant.
Working through technical challenges
The project was completed in 2020 and produced many learnings about operations that helped inform future implementations of this technology. The washer screws, which separate the bitumen, water, sand, and clays through mechanical means, were a new technology for oil sands at the time, and the crew learned a great deal about their operation. The screws performed quite well, as there were no issues with rocks or sand plugging and the wear incurred on the screw flights was unexpectedly minimal.
The main challenge on the tailings side was handling product that did not meet set quality standards, i.e. it was off-spec material. Since off-spec tailings tend to be wetter than normal, material ran off from the underside of the conveyor and impacted the rollers and associated mechanical components, building up in hoppers, freezing to conveyors and overflowing from conveyors. These issues are typical for conveyor systems and several solutions were identified to mitigate them. A belt wetting system was adopted as part of winterization measures which helped significantly to address the freezing problems on the ore feed conveyor.
What’s next?
The pilot was successful in demonstrating the feasibility of the IPEP concept, but at the time of completion, still required further optimization and refinement to achieve all the original the key performance indicator targets and fully capture all processing data for full plant design. In 2021 ERA funded a follow up project– In-Pit Extraction Process Demonstration – that was integrated into the development path of IPEP to address some of the residual development objectives from the IPEP pilot project. Canadian Natural stated in 2024 their long-term projects at their oil sands operations include combining IPEP and other innovations to increase annual bitumen production, reduce GHG emissions and lower reclamation costs.