On 1 December 2016, BP (60.5% and operator) sanctioned the Mad Dog Phase II development in the deepwater Gulf of Mexico (GoM). BP and partners BHP Billiton (23.9%) and Chevron (15.6%) operate the Mad Dog field, which began production in January 2005. The second phase commercialises southern segments of the field that were discovered in 2009 and 2011. The project was first evaluated in 2012 and has been through multiple revisions as the partners honed in on an optimal development solution. We expect first production in late 2021. Our current view is that the project breaks even at US$47/bbl Brent (real, NPV10), however, reserves upside and further project efficiencies could bring this down to US$40/bbl. For BP, Phase II is another step towards re-engineering its portfolio to operate at current oil prices and balance value and volume.