Established in 1958, Sichuan Petroleum and Natural Gas Construction Engineering Co., Ltd. (hereinafter referred to as Sichuan Youjian) is the first large-scale comprehensive professional construction enterprise engaged in the installation of long-distance natural gas pipelines and their supporting projects in China. The company has the first-class qualification of national general contracting of petrochemical engineering construction, ranking 52nd among the 500 largest construction enterprises in China. It is a large-scale comprehensive construction enterprise integrating chemical and petroleum engineering installation, pressure vessel manufacturing, electrical automation control and communication system installation, pipeline anticorrosion and insulation, mechanical processing, civil engineering, transportation, design, scientific research, telecommunications, pipeline inspection, welding technology development and training. The company has more than 4,000 employees, including professional and technical cadres 1067, and 406 project managers who have passed the national examination. There are 2824 skilled workers. Among them: worker technician/KOOC-0/6/KOOC-0/person (32 senior technicians), welder with international API qualification/KOOC-0/90, welder with DVS European welding qualification certificate (Germany)/KOOC-0/69. There are more than 4,000 sets of main equipment, with fixed assets of 475 million yuan. It has passed the quality management system certification of GB/Ti9001—2000IBT ISO 9001:2000, the qualification certification of HSE management system, the qualification certification of pressure piping installation (GA, GB, GC) of the State Bureau of Technical Supervision, and the design and manufacture of ASME pressure vessels of the American Society of Mechanical Engineers. The company's market footprint covers Sichuan and Chongqing, Beijing, Tianjin, Xinjiang, Inner Mongolia, Shaanxi, Hebei, Shandong, Guangdong, Fujian and other regions, radiating the whole country, ranking among overseas markets, and occupying a relatively broad territory in international oil and gas cooperation and development areas such as Turkmenistan, Kazakhstan and Iran.