Associated Press: Oil services contractor Halliburton Inc. says it safely finished a cementing operation 20 hours before a Gulf of Mexico rig went up in flames. In testimony prepared for a congressional hearing Tuesday, Halliburton says it completed work on the well according to accepted industry practice and federal regulators. Halliburton executive Tim Probert says a pressure test was conducted after the work was finished, and the well owner decided to continue. A copy of the testimony was obtained …