GENEVA, May 9 -- CHINA NATIONAL PETROLEUM CORPORATION (9 Dongzhimen North Street,Dongcheng District, Beijing 100007), 中国石油天然气集团有限公司 (中国北京市东城区东直门北大街9号), CNPC TUBULAR GOODS RESEARCH INSTITUTE (32 Dianzier Road, Yanta District,Xi'an, Shaanxi 710065), 中国石油集团工程材料研究院有限公司 (中国陕西省西安市雁塔区电子二路32号), XI'AN SANHUAN PETROLEUM TUBULAR GOO...