Oil Sands Tailings Management Project

Authors
Chris Godwalt
Peter Kotecha
Craig Aumann
Resource Date:
2010
Page Length
64

The Oil Sands Leadership Initiative (OSLI) is a collaboration of five progressive oil sands operators (ConocoPhillips Canada, Nexen Inc., Statoil Canada, Suncor Energy Inc. and Total E&P Canada), with the Government of Alberta participating as an observer, working to advance the development of the oil sands industry in an environmentally, economically and socially responsible manner. The OSLI members identified Water Management as one of the target areas for a step change improvement in performance through collaborative efforts. Alberta WaterSMART was engaged to help develop and manage the various projects arising from the work in water management. One of the projects with the highest potential for achieving results was the development of a regional water management solution. Currently, oil sands producers in the Athabasca Region optimize water sourcing and disposal individually with a focus on fresh water conservation and economics. Mines source water from the Athabasca River with no discharge of process-affected water to the river, while Steam Assisted Gravity Drainage (SAGD) operators are considering distant saline aquifers for their source water requirements. The Tailings Water Management Project is Phase 1 of a four phase project to study the Environmental and Economic Footprint (EEF) benefit of collaborative solutions for Athabasca oil sands production water supply and disposal. The specific goal of this Project was to identify tailings treatment technologies which could be implemented today, and to develop and assess options for optimizing regional oil sands production water sourcing and disposal. Alternatives were split between sub-regionally integrated and regionally integrated solutions in which sub-regional systems used a common SAGD supply and mines managed their disposal needs independently, and regionally integrated solutions involving completely integrated mining/SAGD solutions by transferring tailings water to SAGD operations. Sub–regionally integrated SAGD water source alternatives included the Athabasca River, saline aquifers, and municipal wastewater. Regionally integrated alternatives combined mine water disposal and SAGD water supply. Rather than focusing solely on fresh water conservation and economics, alternatives were assessed on the basis of their total EEF, including greenhouse gas emissions, wastes produced, and land disturbance. Alternatives were evaluated using a consequential life-cycle assessment methodology, focusing on quantifying key performance indicators relative to baseline operations. While the intent of the Tailings Water Management Project was to develop and present solution alternatives and opportunities for regional optimization, the project did not attempt to rank potential solutions. Impact categories quantitatively assessed footprint. However, it was not possible to quantify the effects of all issues (for example the degradation of a saline aquifer or the reduction in tailings TDS) in these numerical calculations. As ranking systems are ultimately the result of an assessment of social choices which are qualitative in nature, there is inherent uncertainty regarding how stakeholders will value different quantitative and qualitative impacts. While methods exist to help stakeholders arrive at such decisions, rankings will still vary depending on group composition and goals. Thus, the results of this project provided the “raw material” to advance subsequent discussions on this topic. Directionally, Phase 1 results supported the premise that large, regionally integrated solutions have a lower EEF than sub-regional systems. Results further indicated that there are existing tailings treatment technologies which, with more testing and development, may be viable for commercial deployment by 2015. Regional water management solutions out-performed sub-regional options on all indicators, except for Fresh Water Consumption. Sub-regional water management solutions out-performed regional water management solutions for Fresh Water Consumption only by degrading saline aquifers. However, it was questionable whether saline aquifers had the capacity to deliver the volumes of water needed to support future SAGD operations. Based on this analysis, OSLI is proceeding to Phase 2 of the project, developing the most promising alternatives including the business models to implement the selected solutions. While the OSLI Tailings Water Management Project was able to conclude that regionally integrated solutions have a lower EEF, the work conducted was directional in nature due to the limited time available, data used, and knowledge gaps identified. In addition to selection and development of preferred alternatives, Phase 2 of the Regional Water Management Solutions Project will need to address the following issues: · Improving data reliability through incorporating actual operational data and company forecasts · Conducting research to fill the knowledge gaps identified · Piloting tailings treatment technologies to generate data required for design of full scale facilities Finally, while operational data, further analysis, research and piloting will allow more accurate calculation of the impacts of the different design alternatives, ranking the design alternatives requires engaging with stakeholders to rank these solutions based on the quantitative and qualitative factors discussed above. This requires guidance from both government and industry regarding which stakeholders to engage in order to validate and select the “best” solution for implementation.