Saleski Plot Plan

The Saleski Pilot is one of the most innovative SAGD projects in the Oil sands. The Pilot is unique in that it is being built to improve on a proven extraction method  - SAGD by combining steam with solvents – a technique called solvent-cyclic SAGD or SC-SAGD. The result is not only a reduced environmental impact through less water use and lower carbon emissions, but more efficient and cost-effective operations.

Where the steam comes from: Source Water Wells to Production

SAGD is highly efficient at producing Bitumen from the oil sands. Two parallel horizontal wells are drilled into bitumen reservoirs below ground. Slowly, steam is pumped into the top injector wells, heating the thick bitumen. As the bitumen warms up, gravity takes over. The mobilized bitumen drains down into the lower producer well that brings the bitumen back up to the surface for processing. Laricina’s operations do not have tailings ponds.

Our source water for steam generation comes from the Lower Grand Rapids Formation. The Grand Rapids Formation is named for the spectacular Grand Rapids on the Athabasca River, which are produced by the river spilling over large concretions as the riverbed intersects the Lower Grand Rapids sand layer. The source water that comes from the Lower Grand Rapids Formation is not fit to drink or suitable for human, livestock or agricultural use.

The source water for the Saleski Pilot starts with the water source wells (WSW). We have two WSWs on the Pilot plant site, at the upper right of the Pilot plot plan diagram, with the remaining four wells about five kilometres west. The source water is pumped from the wells through a four-inch non-metallic pipeline and into a source water tank located in the treatment tanks in the Tank Farm seen towards the left of the diagram. The wells are powered by a dedicated remote generator and controlled in the Control Room to the left of the Tank Farm.

The total production capacity of the wells is 1,600 m3 per day, easily meeting the Pilot’s requirement of approximately 600 m3 per day of water.

From the source water tank, the water is filtered and softened before arriving in the boiler feed water tank. The water then flows through heat exchangers, that pre-heat the water from the hot production fluids before entering the boiler. The boiler is a 50MM BTU once through steam generator (OSTG) that creates 80 per cent quality steam.

As our SAGD wells require 100 per cent quality steam, the steam must first be separated in a high pressure steam separation module. From here, the 100 per cent quality steam flows to the wellhead metering skids located by the Wellhead Area to the right of the diagram. Steam condensate, known as blow down, from the high pressure steam separation module flows back through heat exchangers and to the boiler blow-down tank. A portion of the boiler blow-down is recycled for use as boiler feed water.

Any excess blow down containing residual dissolved solids is combined with regeneration and backwash wastes from water treatment and sent to the disposal tank in the Tank Farm. Water from the disposal tank returns via a non-metallic pipeline to the two water disposal wells (WDW), one located near the WSW on the plant site and one about five kilometres to the west.

Returning to the Wellhead Area, we have three production well pairs. Initial operations will inject steam alone into the first well-pair for approximately one year in order to validate steam chamber development in the reservoir and to gather baseline temperature, flow and production information. This will be followed by the injection of solvents with reduced steam. The extra steam capacity will be used to start the second well-pair. The steam-to-solvent sequence is planned to be repeated with the third well pair.

Oil water emulsion production from the well pairs flows initially to an inlet separation vessel, called the inlet degasser in the Inlet and Produced Gas Area. Production flows under sufficient pressure from the bottom hole pumps that little vapour is generated, so flows from the wells can be measured essentially as a liquid-only stream. At the first inlet vessel, the inlet pressure is adjusted to treatment pressure. Vapours, such as produced gas and evaporated solvent, flash into the produced gas system. It is essential to flash the produced gas and evaporated solvent to prevent stripping away the Diluent that is needed for the treatment process.

Liquids from the inlet vessel are cooled, mixed with diluent and sent to the free water knock out (FWKO), located in the lower mid-right of the diagram. The FWKO removes all but about 10 per cent of the remaining water. The remainder then flows to the treater vessel to the left of the FWKO, where the water content is reduced to a pipeline specification of 0.5 per cent bottom solids and water.

The low-water-content oil now flows to the oil stabilizer, where temperature and vapour pressure of the product is reduced to that required for trucking or pipelining. The product is cooled to shipment temperature and sent to the dilbit storage tanks or bitumen blend tanks located at the left of the diagram in the Tank Farm. Bitumen blend is trucked from the Truck Loading and Unloading Area.

Meanwhile, back at the Inlet and Produced Gas Area at the centre of the diagram, vapours from the inlet degasser, the FWKO, the treater and the oil stabilizer are combined, cooled, and separated in the Solvent Area recycle process into natural gas; diluent for recycle; Propane for recycle; and water for disposal. Supplementary solvent is trucked in and vapourized prior to injection.

The plant has a high pressure flare stack used for emergency relief known as the Flare Knock Out.