Patent ID: 7610818

Claim:
A method for measuring the flow rate of a viscous fluid such as bitumen froth having a certain temperature through a pipeline having an inner diameter, comprising: providing a conduit comprising an approach section and a venturi section having in series a converging section and a throat section, the converging section of the venturi section being disposed relative to the approach section and the throat section having an inner diameter less than the inner diameter of the approach section; inserting the conduit into the pipeline or between two pieces of pipe comprising the pipeline; allowing the viscous fluid to flow through the pipeline and through the conduit; heating at least a portion of the conduit to a temperature of about the temperature of the viscous fluid or higher to reduce adherence of the viscous fluid to an inner wall of the conduit as it flows therethrough; and measuring the pressure difference ΔP between two points that are separate from one another in the flow direction, one point being on the approach section and the other point being on the throat section, to calculate the flow rate in the pipeline.