Shares in Empyrean Energy lost around one-sixth of their value on Tuesday morning after the oil company said it has run into problems on its Quinn-3H well on the Riverbend project in Texas when trying to clean out debris.The operator, Kresent Energy, is sizing up whether to have another crack at fishing out a piece of tubing and mill from the well, or whether to try a different tack and attempt a completion in the shallower Saratoga formation that has exhibited potential net pay on logs.'The gas pressures encountered and the flow rates, albeit for an extremely short period of time have given the operator enough encouragement to be planning a second well to test the target Austin Chalk zone,' the company said.