Foaming Mitigation and Process Upset Management: Operation Case Study

Abstract Since commissioning of the new main bulk separator in X, Field Petroleum Development Oman station in 2008; the separator had gone through serious of problems of fluid foaming. Throughout 2009 and until early 2010, X station gone through big instability of production issue mainly due to the main bulk separator upset which resulted in measurable production impact. Some amount of water is exported to main station via the GRE line that causes increase in the GRE line pressure and therefore forced to shut-down of X oil producers. This disturbance in the system as flow assurance issues, observed at least every 2 months with a minimum of 2 weeks per each disturbance. The average water cut in the export of X Field in 2009 was around 7% although during the upsets it reached sometime up to 85%. In November 2009 an integrated multi disciplinary team was formed to look at this issue and action plan has been set after identifying the route causes of the instability and foaming problems. The latest production and process upset in the system during the past 2 months is even worse than the 2009 upsets (with bigger lost production impact), and took longer than usual with all the actions and measures that has been taken earlier. Based on the fluid characterization study, emulsion and foaming testing, the root caused of foaming is due to excessive CO2 content from reservoir, sodium meta silicate, carboxylic acid and shearing by artificial lifting ESP downhole and the proactive surveillance and injection of novel anti foaming polymer type combined with emulsion breaker chemicals as mitigation is success to inhibit foaming.