VERTICAL “WICK ” DRAINS AND ACCELERATED DEWATERING OF FINE TAILINGS

• Main Authors: In Oil Sands, Patrick Sean Wells, Suncor Energy Inc, Fort Mcmurray, Jack Caldwell Robertson Geoconsultants
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Canada; Fort McMurray; Mine Lake
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.625.4186; http://www.infomine.com/library/publications/docs/Wells2009.pdf

Suncor Energy Inc. is committed to a programme of accelerated research and field trials of tailings technologies with a focus on the closure and final reclamation of soft tailings areas. The work described in this paper was undertaken specifically with regard to Ponds 5 and 6, located in Suncor’s Lease 86/17 area to the north of Fort McMurray, AB, Canada. The tailings in these ponds are soft materials that are the product of commercial development of tailings treatment technologies, ongoing since 1995. One line of research evaluated the potential for the use of petroleum coke (a by-product of upgrading operations) to build a trafficable cap on the soft tailings. A second line of research evaluated the use of enhanced soft tailings dewatering systems (vertical “wick ” drains) in the capped, soft materials. Together these technical approaches may decrease the consolidation time of the soft tailings within these ponds, allowing for an accelerated placement of a final reclamation cover. This paper discusses 2009 field trials of vertical “wick ” drains installed in very high fines, low density tailings in Pond 5. A description of the trial operations is provided, along with preliminary data and conclusions. Findings so far indicate that vertical drains can be an important component in the dewatering of soft fine tailings in oil sands deposits. BACKGROUND Closure and reclamation of oil sands tailings areas has been a focus of industry and academic research efforts for over thirty years. One of the key areas of interest is the dewatering of low density, high fines materials which are the result of oil sands ore processing. Such materials are currently contained within tailings storage facilities, and may benefit from some measure of dewatering through enhanced methods such as vertical (or “wick”) drains, capping and long-term storage such as end-of-mine lake capping, or long-term consolidation monitoring and surface water removal.