Reuters - Transocean Ltd, owner of the world's largest offshore drilling fleet, said it could take up to 18-24 months for demand to recover as customers delay drilling programs. Demand for offshore rigs is tapering as major oil companies trim exploration and production budgets in the face of investor demands for higher returns. Transocean, whose deepwater fleet is relatively older than that of its competitors, said about 19 of its deepwater and ultra deepwater rigs will be up for contracts in 2014. In comparison, rival Ensco Plc will have eight rigs available for contract, while Seadrill Ltd will have five in 2014. A lease normally runs for five years or more.