Agence France-Presse: The disaster caused by the Gulf of Mexico oil spill has cast doubts over the future of deep water exploration and is likely to have the long-term effect of raising oil prices, analysts say. British oil giant BP has struggled to stem the crude gushing from a ruptured underwater pipe after the Deepwater Horizon rig it leased exploded before sinking into the sea on April 22, causing a major environmental disaster. “The benefits of being able to drill and produce in deep and …