Drag Reducing Agent (DRA) is used in numerous single-phase pipeline systems to reduce operating pressures, increase capacity, and decrease reliance on pumping. For a given pipeline system, prediction of the DRA performance is unreliable. Therefore, a reliable laboratory flow-loop test, the results of which could be scaled-up to the full-scale pipeline, would be valuable.

During transportation, the oil temperature decreases, the rate of decrease depending on factors such as flow rate, insulation, and surrounding medium. It has been shown in our previous laboratory studies that DRA performance, normalized by a function of Re. (f) 0.5, in a non-isothermal system can be 20% below that of an isothermal system. This behavior has shown to be dependent on the characteristics of the oil (e.g. wax appearance temperature, wax content, oil composition etc.).

The above laboratory observations have lead to a method for scaling-up flow-loop test results to enable prediction of the full-scale field data. The subject of this paper is the validation of these scale-up methods. For this validation, flow-loop tests were performed on the crude oil from a well instrument singlephase export pipeline. The loop test results were scaled-up without knowledge of the DRA performance in the actual pipeline. In the loop tests and field trial a range of DRA concentrations were tested for DRA performance, effect of DRA on wax deposition, and the effect of wax crystallization on DRA. The phenomenon of the effect of the DRA on the wax deposition profile, as shown in our previous studies, was confirmed in this test. The scaled-up loop test results agreed with the field measurements to within ±5% for the tested DRA concentration and ± 13% for the extrapolated concentrations.

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