Drag Reducing Agents (DRAs) are commonly ultra-high molecular weight (UHMW) polymers used to reduce frictional pressure loss in a fluid flowing in a turbulent regime pipeline, thus, allowing to enhance its production capacity. The increasing oil fields development in challenging environments (such as, for example, deep water conditions) and the request to maximize their production have led to an Eni R&D project whose aim was to develop/find suitable DRAs for umbilical injection, since the conventional UHMW DRAs are not feasible for these tougher scenarios.
Initially, a market screening of the major chemicals providers portfolio has been done with the purpose to find conventional DRAs whose employment in deep water injection systems does not lead to chemical umbilical plugging.
Due to the failure of this scouting, the objective of the work reported in this paper was to carry on an experimental study of performance assessment, from one side, of chemicals with surfactant properties not specifically formulated as DRA and, on the other side, of the dilution of conventional polymeric DRAs in solvent.
All the experimental evaluations carried out at lab scale were performed with a specific test apparatus able to estimate additives capability to reduce pressure drops under turbulent flow regime at different Reynolds numbers.
Finally, a new commercial surfactant-based Flow Improver chemical, suitable for the injection in umbilical systems, was identified by experimental tests as promising in reducing pressure drops. Thus, in 2020 a sealine with multiphase fluid production, in a deep-water Eni field, was selected for a trial. A preliminary hydraulic sensitivity analysis was performed, by means of fluid dynamic simulations, which confirmed the suitability of this flowline for the scope and predicted a potential production gain.
