Basin Exploration reports that on July 5th while a caisson was being driven and welded over the D-6 well on West Delta Block 58, an unexpected release of gas occurred from the vicinity of the adjacent D-5 well. The heat from welding apparently ignited the gas and caused a fire. The fire was extinguished and all personnel from the rig were evacuated safely. There were no injuries and no environmental damage associated with the incident. Diamond Offshore's jackup, Ocean Crusader, was performing completion operations on the well at the time of the fire.