Opec was buoyed this week by upwards revisions to global demand expectations in the IEA and Opec’s latest monthly reports. But all indications are still that the market imbalance will persist into 2019, with global stockpiles remaining stubbornly high. Moreover, growing evidence of a slowdown in Chinese demand growth could further extend the supply glut (MEES, 1 September).

Nine months into what was initially planned to be a six-month deal to limit output from 1 January (MEES, 2...