Nine Years Operational Experience of the Vega Field – Design, Experience, and Lessons Learned

摘要

The Vega field is a gas condensate / volatile oil asset located in the Northern part of the North Sea. It comprises three subsea templates, daisy-chained on a 52 km long subsea multiphase flowline to the Gj?a host platform. The high temperature, high pressure field was developed by Norsk Hydro and Statoil and came onstream in 2010; it came under operatorship of Wintershall in 2015. A lot of operational experience was gained within those years. The paper will reflect on the assumptions that led to the design of the asset and juxtapose this with the findings after first oil. Within this, especially the subject of paraffin precipitation will be highlighted. This was perceived as the highest risk to the asset upon development. Later field life, however, showed no indication of wax precipitation at all. Furthermore, and especially since the takeover by Wintershall, production optimization and prolonging field life has been a strong focus. The paper will showcase several aspects of this, like re-vitalizing wells through acid stimulations, extending lifetime with an infill well campaign, a new spare part strategy, or chemical optimization on the continuous hydrate inhibition cocktail. Moreover, it will also display further activities to extend lifetime even more by changes in the hydrate philosophy. The story shows that with fresh eyes and new approaches, also smaller fields can be optimized efficiently, leading to increased lifetimes and improved economics.