Sou Hu Cai Jing·2025-06-24 03:51Group 1 - The State Intellectual Property Office of China has published a patent application by China National Petroleum Corporation (CNPC) for a high-frequency resistance welding high-strength large-strain oil casing and its preparation method and application, published under CN120193215A, with an application date of December 2023 [1] - The patent details a composition for the oil casing, including specific percentages of various elements such as C: 0.17% to 0.27%, Si: 0.15% to 0.33%, Mn: 1.35% to 1.65%, and others, designed to meet the demands of complex working conditions in oil and gas wells [1] Group 2 - China National Petroleum Corporation was established in 1990, located in Beijing, primarily engaged in oil and gas extraction, with a registered capital of 48.69 billion RMB [2] - CNPC has invested in 112 companies, participated in 5,000 bidding projects, and holds 1,446 trademark records and 5,000 patent records [2] - China National Petroleum Group Engineering Materials Research Institute, founded in 2021 and located in Xi'an, focuses on specialized equipment manufacturing with a registered capital of 679.11 million RMB [2] - The Research Institute has invested in 4 companies, participated in 1,253 bidding projects, and holds 15 trademark records and 647 patent records [2]