UPDATE: Relief Well Drill Rig Returning To Gulf Oil Spill Site -BP

(Updates with details, background) HOUSTON (Dow Jones)-- A drill rig working on a relief well is returning to the site of the Deepwater Horizon oil spill as a tropical storm that caused its evacuation petered over the U.S. Gulf of Mexico, a BP Plc (BP) spokesman said Saturday. The Development Driller 3, which is drilling the first of two relief wells designed to kill the leak, is "moving back to the site," BP spokesman Steve Rinehart said. Rinehart added that it was unclear when the vessel would be back. Before the evacuation was decreed late Thursday, the rig was completing the casing of a relief well, in preparation for it to intersect with the well that has spewed millions of barrels of crude in the Gulf. The intersection was scheduled for the end of July before the evacuation happened. It will take 48 hours to lay the casing once operations restart, retired Coast Guard Admiral Thad Allen, who heads the federal oil spill response effort, said in a conference Friday. The spill has been shut in since last week, as BP began testing a new containment cap on it. The well remained shut-in during the evacuation, Rinehart added. Pressure continued to slowly build up, BP said, strengthening confidence that the well isn't damaged and can remain shut in. Another BP spokesman had told the Agence France Presse that the decision to return the vessel was made overnight. The National Hurricane Center discontinued tropical storm warnings on Saturday morning, as Tropical Depression Bonnie was "hanging in there" with winds of 30 miles per hour. The depression, which briefly became the second named tropical storm of the season, is in the central Gulf of Mexico and is seen heading northwest toward Louisiana and Mississippi, according to NHC charts. -By Angel Gonzalez, Dow Jones Newswires; 713-547-9214;angel.gonzalez@dowjones.com (END) Dow Jones Newswires July 24, 2010 11:19 ET (15:19 GMT)