INTERNATIONAL PATENT: CHINA NATIONAL PETROLEUM CORPORATION, 中国石油天然气集团有限公司, CNPC TUBULAR GOODS RESEARCH INSTITUTE, 中国石油集团工程材料研究院有限公司 FILES APPLICATION FOR "WEAR-RESISTANT AND ANTI-CORROSION MATERIAL AND PREPARATION METHOD THEREFOR AND WEAR-RESISTANT AND ANTI-CORROSION PLUNGER ROD AND PREPARATION METHOD THEREFOR AND USE THEREOF"

GENEVA, May 18 -- CHINA NATIONAL PETROLEUM CORPORATION (9 Dongzhimen North StreetDongcheng 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 Dianzi Er Road, Yanta DistrictXi'an, Shaanxi 710077), 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) filed a patent application (PCT/CN20...