Effects of Density and Viscosity Measurements Errors at the Pipeline Batch Tracking System

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Batch Tracking System (BTS) is commonly found as pipeline operational real time functionality within operator companies’ control room. It tracks batches, offering amongst other information their volumes, positions and Estimated Time of Arrival (ETA). In order to reliably calculate those system outputs, BTS requires operational information like pressures, temperatures and flow rates, elevation profile, as well as some fluid physical properties, being the most important ones density and viscosity. This work aims to track the actual necessity of measuring those variables and to establish their impact on ETA in a 700km long South African multi-product pipeline network. Thus, the flow dynamic was analysed using a commercial pipeline flow simulator, where the network operational scenario was entirely reproduced and then variations of density and viscosity were introduced to track the effects on batches’ ETA, per pipeline segment. As a result of the study, which employed usual refined products such as petrol and Diesel, it was identified: (i) both variables played a relevant role on the ETA estimation requiring to be accurately determined, even though viscosity is the most relevant; (ii) viscosity showed a more predictable behaviour as flow resistance shall take place independently of the elevation profile; (iii) density was highly dependent of the elevation profile; and (iv) the biggest ETA accumulated variation verified was around 128 minutes (due to a variation of –20% in the viscosity value) and the lowest one around 4 minutes (due to a variation of –2% in the density value).