By Kate Abnett and Alex Lawler BRUSSELS/LONDON (Reuters) -OPEC told the European Union on Monday that current and future sanctions on Russia could create one of the worst ever oil supply shocks and it would be impossible to replace those volumes, and signalled it would not pump more. European Union officials held talks in Vienna with representatives of the Organization of the Petroleum Exporting Countries amid calls for the group to increase output and as the EU considers potential sanctions on Russian oil. “We could potentially see the loss of more than 7 million barrels per day (bpd) of Russ…