With Brent marking three straight weeks above $60/B, an extension of the output deal to end-2018 suddenly looks less certain.

With less than two weeks to go until the energy ministers of 24 producing states descend on Vienna for the 30 November Opec meeting, the picture is growing increasingly blurry. Influential monthly reports from the IEA and Opec itself, released this week, offer contrasting pictures of the global supply/demand balance to end-2018. Both the bulls and the bears within...