THE CHALLENGE
Enhanced oil recovery on a deepwater subsea tieback depends on how gas lift is injected at the riser base. Operators had no real-time view of the optimum injection rate, and slug formation in the gas lift riser interrupted flow and forced conservative operation well below the production the system could sustain.
THE SOLUTION
Three models run against live SCADA data: an EOR Predictive Model relating oil production to reservoir parameters and choke valve outlet pressure, an AI and physics-based simulation model covering choke outlet through the riser base and gas lift riser to the host platform, and a host platform model for separation and gas processing. A Slug Prediction Model flags slug formation early, identifies the cause, and switches the AI Optimizer’s objective from oil production maximization to gas lift flow while the upset is mitigated. The optimizer manipulates outlet pressure, gas lift flow, host separator pressure and temperature, compressor outlet pressure and other wells’ gas lift flow within gas processing capacity and operating limits, and optimum set points are implemented in SCADA.
THE IMPACT
2.8% more oil production, slug events predicted and mitigated before they interrupt flow, and injection decisions made from live data rather than periodic sampling at remote locations.