Feb 21 (Reuters) - Ensco Plc, owner of the world's second-largest offshore drilling fleet, expects contract drilling expenses to rise by 19 percent this year as a pick-up in drilling activity leads to more spending to get rigs ready to work. Ensco announced just this week a contract with Total for its newly built DS-7 ultra-deepwater drillship off Angola at an average rate of $648,000 per day, which will start later this year. Jay Swent, Ensco's chief financial officer, said revenues f