LJRB(SH:600853) Sou Hu Cai Jing·2025-07-29 06:02Group 1 - The State Intellectual Property Office of China has published a patent application by Sinopec Petroleum Engineering Technology Service Co., Ltd. for a "downhole sand cleaning system under fluctuating pressure," with publication number CN120384709A and application date of June 2025 [1] - The patent describes a downhole sand cleaning system that includes a sand cleaning operation system and a drilling fluid circulation system, featuring multiple second casing pipes and sand collection equipment [1] - The proposed system utilizes a flow regulation device and a boosting device to create high-frequency fluctuating pressure, allowing for effective lifting of sand-containing fluid through a jet device [1] Group 2 - Sinopec Petroleum Engineering Technology Service Co., Ltd. was established in 1994, located in Beijing, with a registered capital of approximately 1.898 billion RMB [2] - The company has made investments in 14 enterprises and participated in 126 bidding projects, holding 1 trademark and 1,904 patent records [2] - Sinopec Zhongyuan Petroleum Engineering Design Co., Ltd. was founded in 1993 in Zhengzhou, with a registered capital of 100 million RMB, having invested in 2 enterprises and participated in 2,771 bidding projects, holding 243 patent records [2]