Alternative Bitumen Extraction Technology
Funded through Round 4: Carbon Capture plus Energy Technology in 2012, Imperial Oil Resources Ltd. conducted a pilot demonstration of the non-thermal, in-situ bitumen recovery process, called Cyclic Solvent Process (CSP). The project was completed in 2018 and assessed the commercial viability of CSP and cost-effective deployment of the technology.
CSP utilizes injected solvent to reduce the viscosity of the bitumen, enabling its production from the sub-surface. The liquid-phase solvent is injected into a horizontal well in a cyclic manner. Following injection, pressure is reduced, and the mixture of solvent and bitumen flows back to the same horizontal well and is produced to surface using artificial lift. Because CSP is a non-thermal process, it avoids the key challenges associated with traditional thermal processes, including cyclic steam stimulation (CSS) and steam assisted gravity drainage (SAGD). Two of these key challenges are the production of greenhouse gases (GHGs) arising from burning natural gas to produce steam, as well as lower thermal inefficiencies, which limit applicability to thinner and/or lower bitumen saturation reservoirs. CSP’s GHG intensity reduction of about 80 per cent compared to CSS may expand its application to reservoirs where a steam-based process would ordinarily be considered. Beyond the GHG benefits, CSP requires almost no water and represents a water-conscious bitumen extraction process, as it does not utilize steam.
Early-Stage Challenges Inform Future Operations
The project experienced challenges in the early stages of the pilot that were eventually overcome. Specifically, the surface lines and the production pipeline experienced clogging with heavy liquid during the early pilot operation. The project team resolved this by replacing diluent with a flow-assurance solvent. This reduced the formation of heavy liquid at the pilot conditions, preventing future plugging. Additionally, inadequate methanol treatment and residual water from commissioning activates led to hydrate formation within the production pipeline. Gas hydrates are crystalline compounds that occur when small gas molecules contact with water at certain temperatures and pressures. The project team performed a hydrate removal procedure, which was successful. These initial challenges helped the technology become more commercially viable from a reservoir and operational perspective. In addition, these important learnings will directly influence future commercial design choices.
What’s next?
The CSP project demonstrated a solvent-only recovery process, building on existing and ongoing solvent-assisted processes in the Cold Lake region. CSP could be a solvent-only technology commercialized in the future, but in the meantime, Imperial continues to commercialize solvent-assisted processes at some of its operations to help reduce GHGs and water consumption.