Sou Hu Cai Jing·2026-01-13 07:39Group 1 - The core point of the article highlights that China National Petroleum Corporation (CNPC) has obtained a patent for a method and system for evaluating casing pollution, with the patent number CN115828715B and an application date of October 2022 [1] - CNPC was established in 1999 and is primarily engaged in oil and gas extraction, with a registered capital of 18,302,097,000 RMB [1] - CNPC has made investments in 1,296 companies and participated in 443 bidding projects, holding 38 trademark records and 5,000 patent records, along with 168 administrative licenses [1] Group 2 - China National Petroleum Engineering Technology Research Institute Co., Ltd. was established in 2006 and focuses on research and experimental development, with a registered capital of 57,038,875.182 RMB [1] - The research institute has invested in 4 companies and participated in 573 bidding projects, holding 33 trademark records and 2,218 patent records, along with 8 administrative licenses [1]