DANBURY, Conn.--(BUSINESS WIRE)--Praxair, Inc. (NYSE:PX) announced it has signed a long-term contract to provide industrial gases to the China National Offshore Oil Company (CNOOC), a Fortune Global 100 company and one of the largest in China. The project, expected to start up in 2017, will enable the reliable and efficient supply of industrial gases for CNOOC’s refinery and downstream chemical production. Praxair will build, own and operate two 2,400 tons per day air separation plants in the H