Brent crude is once again testing a trendline originating from the July 2008 record of $147.50 a barrel, following a breakdown of OPEC+ talks on boosting supplies. A climb above could signal further gains with some commentatorstalking about a return to $90 a barrel in the short term. Further out, the OPEC+ crisis could hurt prices if it imperils the alliance and leads countries to pump at will.