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Suncor Submits Fort Hills Oilsands Tailings Plans

[Daily News] How Suncor Energy Inc.’s proposed Fort Hills mine will meet a provincial regulators new rules is the first such plan to be made public.

Suncor is 60% owner of the mine by virtue of having merged with Petro-Canada earlier this year. Fort Hills’ other owners are Teck Cominco Limited and UTS Energy Corporation with 20% each.

The Alberta Energy Resources Conservation Board (ERCB) has received plans with dates for construction, use and closure of fluid tailings ponds from six Alberta oilsands operators as required by Directive 074: Tailings Performance Criteria and Requirements for Oil Sands Mining Schemes.

The directive requires operators to prepare tailings plans and report on tailings ponds annually, reduce fluid tailings through fines captured in dedicated disposal areas (DDAs), and convert fines into trafficable deposits which are ready for reclamation five years after operations have ceased.

Albian Sands Energy Inc., Canadian Natural Resources Limited, Imperial Oil Resources Ventures Limited, Shell Canada Inc., Syncrude Canada Ltd. and Suncor have submitted their tailings plans by the deadline of Sept. 30. The ERCB will now conduct a detailed and comprehensive technical review of the plans. The plans will not be approved until the regulator is satisfied that they comply with its requirements.

Tailings are waste generally composed of water, sands, silt, clay and residual bitumen. Alberta’s inventory of fluid fine tailings that require long-term containment is now 720 million cubic metres.

The tailings directive establishes a minimum mass of dry fines in the oilsands feed expressed as a percentage of total fines in feed that must report to the DDAs. This requirement applies to a one-year period between surveys (expected to be July 1 to June 30 of the following year). The phase-in sequence will be as follows: 20% from July 1, 2010 to June 30, 2011; 30% from July 1, 2011 to June 30, 2012; and 50% from July 1, 2012 to June 30, 2013, and annually thereafter.

It also requires that operators demonstrate to the satisfaction of the ERCB that sufficient monitoring, measurement and sampling are performed to measure and report on the fines in oilsands feed.

Operators are required to submit to the ERCB annual compliance reports for DDAs, and annual tailings plans and pond status reports. Data will be formally submitted to the ERCB on a quarterly and annual basis.

Rather than report annually to the period ending June 30 as requested, Suncor is proposing a different end-of-period: Oct. 31. Collecting DDA and field inventory data on Oct. 31 offers several advantages, it said, including:

• DDA volumetric surveys and geotechnical measurements can be completed safely in an inactive area.

• DDA volumes will not change for several months from Oct. 31 onwards, so field measurements can be collected over a longer period without being impacted by additional DDA deposition. This provides a longer window to organize measurement strategies and obtain accurate measurement results, said the Fort Hills plan.

Fort Hills’ mine plan is based on development activities commencing in 2012 with a production start-up date of third-quarter 2014 and a full production rate of 156,000 barrels of bitumen per day through two extraction trains (78,000 bbls per day capacity each). Bitumen production is scheduled to ramp up to 148,000 bbls per day over the first eight months, then to full production by the end of year three.

The Fort Hills extraction facility will generate three tailings products: a coarse sand tailings stream (CST), a thickened tailings stream (TT) and a tailings solvent recovery unit stream (TSRU).

Deposition of the primary tailings streams is typical of existing operations, said Suncor. CST will be used for upstream cell construction and beaching into the main out-of-pit tailings area (OPTA) pond followed by conventional beaching in-pit, while TT and TSRU streams will be beached into a separated, centerline constructed pond. Deposition of the primary streams will continue in this manner for the life of the mine. There are no plans to incorporate CT or non-segregated tailings technologies to attempt to combine streams.

Each of the tailings streams contain a fines component that is expected to partially segregate from the slurry as it is deposited into its corresponding storage facility. A fluid fine tailings (FFT) component will collect in each tailings storage facility and will be subsequently dredged and pumped during non-winter months to a DDA where it will be deposited in thin lifts and allowed time to partially dry and gain geotechnical strength.

Construction material requirements during bitumen production have decreased dramatically in this plan versus previous Fort Hills plans, said Suncor, due to having mine pits separated with in-situ pillars and the chosen tailings strategy where there is little generation of soft tailings compared to an NST/CT operation.

The Fort Hills DDA concept was developed as Directive 074 was being developed and finalized in 2008 and early 2009 and as such has not reached as high a design level as the other portions of OPTA. However, the project engaged a firm to complete a conceptual design of the TT Drying DDA, the MFT Drying DDA and the revised in-pit deposition strategy with regard to the shared Aurora Boundary slope.

There were no major geotechnical issues identified preventing the plan from progressing to the next stage of development. Fort Hills is estimated to contain more than four billion bbls of bitumen resource.

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