Abstract: A process for transporting viscous oil in a pipeline is described which comprises placing a spherical sealed pig within the pipeline at a desired position; filling a fraction of the pipeline upstream of the pig with a low viscosity fluid such as water; and initiating core flow of a viscous oil such as a heavy or extra heavy crude oil after the first fraction has been filled. The process permits the core-flowed viscous oil to be transported in the same pipeline with a non-core-flowed fluid. To do this, a second pig is placed in the pipeline intermediate the core-flowed viscous oil and the non-core-flowed fluid and a second fraction of the pipeline intermediate the second pig and the core-flowed viscous oil batch is filled with a low viscosity fluid such as water.

Abstract: The present invention relates to a process for restarting core flow with viscous oil after a long standstill period. The process comprises initiating a flow of low viscosity fluid such as water into an inlet portion of a pipeline; gradually increasing the flow of the low viscosity fluid until a desired steady state condition is reached and initiating a flow of viscous oil into the inlet portion of the pipeline after the steady state condition has been reached.