Fort Hills Energy L.p.

Benjamin John Grappolini

Thomas Hann

Shawn Van Der Merwe

Thomas C Hann

A process for operating a bitumen froth treatment operation in turndown mode includes adding solvent to bitumen froth to produce diluted bitumen froth and separating it into diluted bitumen and solvent diluted tailings and in response to a reduction in bitumen froth flow recirculating part of the diluted bitumen into the bitumen froth and returning part of the solvent diluted tailings into the step of separating. A method for turndown of separation vessel for PFT includes sustaining the feed flow to vessel; maintaining solvent-to-bitumen ratio in the diluted bitumen froth; and retaining water, minerals and asphaltenes in a lower section of the vessel while sustaining an outlet flow. The use of diluted bitumen derived from PFT as a viscosity modifying agent of the bitumen froth and an associated process are also provided.

Enhanced turndown process for a bitumen froth treatment operation

More particularly, the model was a dynamic simulation built in HYSYS&#x2122; v7.1. The component slate was simplified and selected to give a vapor and two liquid phases, and have the ability to measure an S/B ratio. All the unit operations were included and modeled as best fit within HYSYS&#x2122;. Pumps were all modelled as standard HYSYS&#x2122; centrifugal pumps with performance curves, settlers were modelled as vertical 3-phase vessels with internal weir enabled&#x2014;the overflow side of the weir is used to simulate the overflow vessels on the settlers. All proposed controllers were included with generic tuning parameters, which control the system process variable (PV) to match a set point (SP). The control algorithm incorporated master PV controllers such as S/B ratio to relate froth and solvent flows and maintain relative material balance relationship between the process streams involved. In this specific simulation, the solvent flows were assigned a slave relationship relative to the bitumen flow; that is, the solvent controller SP was reset based on the bitumen froth flow and the master S/B ratio.

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Calgary, Canada

Benjamin John Grappolini