DOLDRUMS — The OPEC daily price has now spent the whole of May in the low $60-range. It is very close to dropping into the $50s now. Some analysts think the upward momentum that began shortly after the new year has exhausted itself. Others expect the price rise to continue, albeit slowly, into the $70s. But few can be heard to forecast a return to prices above $100 for years to come. Of course, it is worth pointing out that only two of many hundreds of commentators on oil prices said in the first half of 2014 that prices would plunge in the second half of 2014.