Upstream M&A was put on hold in 2015 as the oil price stayed "lower-for-longer". Deal count fell 40% year-on-year. Shell's US$82 billion acquisition of BG was memorable, but easily outstripped the disclosed spend on every other deal combined. In this Insight, we provide an in-depth analysis of the global upstream M&A market in 2015, looking at buyers, sellers, regional activity, valuations and more. For an explanation of why we think the upstream M&A market will recover this year, see upstream M&A: 2016 outlook.