Group 1 - The State Intellectual Property Office of China granted a patent for a "glass plate liquid level gauge and liquid level measurement method" to China Petroleum & Chemical Corporation, Sinopec Guangzhou Engineering Co., Ltd., and Sinopec Refining Engineering Group Co., Ltd. The patent was applied for on August 2021 [1] - China Petroleum & Chemical Corporation, established in 2000, is primarily engaged in oil and gas extraction, with a registered capital of 12,173,968.9893 thousand RMB. The company has invested in 263 enterprises and participated in 5,000 bidding projects, holding 45 trademark records and 5,000 patent records [1] - Sinopec Guangzhou Engineering Co., Ltd., founded in 1998, focuses on professional technical services, with a registered capital of 30,000 thousand RMB. The company has invested in 2 enterprises and participated in 4,290 bidding projects, holding 4 trademark records and 863 patent records [1] Group 2 - Sinopec Refining Engineering Group Co., Ltd., established in 2007, is primarily engaged in water management, with a registered capital of 441,854.35 thousand RMB. The company has invested in 12 enterprises and participated in 63 bidding projects, holding 5,000 patent records [2]