Drag Reducing Agents (DRAs) are commonly used to reduce the frictional pressure loss under turbulent flow conditions. This reduction can potentially lead to a meaningful increase in pipeline production capacity. In the last 20 years, the continuing and growing demand of energy worldwide has encouraged the development of fields in challenging environments (such as deepwater conditions) and to maximize their production. Consequently, the use of DRAs in subsea systems has become more and more stringent. The most commonly used DRAs are ultra high molecular weight (UHMW) polymers suspended in organic carrier able to increase the laminar flow contribution despite to the turbulent one. However, the application of these conventional polymeric DRAs in deepwater conditions, provided to the oil through very narrow umbilical injection line, is not feasible yet. This paper highlights the main criticalities associated to the use of conventional DRAs in subsea/deepwater conditions and shows preliminary results achieved with the aim to:
utilize conventional polymeric DRAs for these applications
explore the use of non polymeric surfactant additives (NPSA) as DRAs
These objectives were pursued utilizing a, lab scale, experimental set up that is able to simulate the real field conditions and to estimate the capability of chemical additives to reduce frictions under turbulent regime. A dedicated scouting of commercially available additives technologies was carried out and results achieved with both traditional polymers and surfactants are reported. An experimental polymeric additive, with proper characteristics at subsea conditions, gave positive results leading to DR﹪ efficiency of about ~ 11﹪ that are, however, 5 time less than conventional polymeric DRA comparatively tested. Positive results were achieved with an anionic surfactant utilized under development.
