Sports
| Wed 01 Apr 2026
Beijing, April 1 -- CNOOC Energy Technology & Services has filed a patent application for Double-channel Ball Valve for Intelligent Sand Prevention Well Completion. This invention was developed by Wei Longgui, Luo Jianwei, Wang Binggang, Liu Chuangang, Liu Jingchao, Qi Haitao, Zhang Yunchi, Ji Juxiang and Liu Peng.
The patent a..