Demulsifying agent simplified model for offshore oil wells

Abstract

This article addresses key challenges in offshore petroleum production caused by multiphase flow instabilities, such as slug flow and emulsion formation. Traditionally, severe slugging is mitigated by increasing wellhead backpressure through partial choke valve closure. In this context, a simplified dynamic model—the fast offshore wells model (FOWM)—was extended to include the effects of demulsifier injection, along with other operational variables such as gas‐lift and choke settings. A case study based on real offshore well data demonstrates that the injection of demulsifier can improve flow stability and increase oil production. Two injection strategies were evaluated in open‐loop simulations: through the gas‐lift system and at the Christmas tree. The results indicate that demulsifier injection reduces mixture viscosity and frictional pressure losses, expanding the stable operating window of the well. However, the simulations also revealed that demulsifier injection alone may not be sufficient to fully suppress pre‐existing limit‐cycle flow instabilities. By integrating demulsifier dynamics into a low‐complexity control‐oriented model, this study highlights both the potential and limitations of chemical demulsification as an operational and control variable for improving flow stability and enhancing oil recovery in deepwater operations.