Tools and Machinery
| Tue 23 Jun 2026
Beijing, June 23 -- CNPC Greatwall Drilling and China National Petroleum have filed a patent application for Leaking Stoppage Equipment. This invention was developed by Shi Lianhai, Tian Ping, Yao Rugang, Peng Huixin, Wang Xiaojun, Xu Tao, Liu Pingquan, Dang Yufeng, Dai Yuncai, Wang Kewei, Han Long and Xiao Shijie.
The patent..