The first "Oxygen-Enriched Claus" project in China's natural gas purification sector has successfully commenced operation.

On April 16th at 11:29, the Wanzhou Branch of Natural Gas Purification Plant under Southwest Oil and Gas Field Company stabilized its daily feed gas processing capacity at 1.5 million cubic meters, marking the successful commissioning of China's first "Oxygen-Enriched Claus" project in the natural gas purification field. It is expected to increase feed gas processing capacity by 38 million cubic meters and sulfur production by 3,839 tons by 2025.

As China Petroleum's first independently designed, operated, and managed high-sulfur purification plant, the Wanzhou Branch initially had a designed daily capacity of 2 million cubic meters, filling a technical gap in China's high-sulfur purification field. It boldly innovated and applied "four new" technologies, creating eight firsts including the first application of China Petroleum's independently developed CPS sulfur recovery process and the first application of China Petroleum's independently developed CPO oxidation absorption tail gas treatment process, providing technical support for the development of ultra-high sulfur gas fields.

In recent years, with changes in feed gas quality, the content of hydrogen sulfide and carbon dioxide in the feed gas entering the Wanzhou Branch has been increasing year by year. To meet production expansion needs, it was necessary to improve the processing capacity of the sulfur recovery unit, making upgrading and transformation imperative.

To fully leverage the production capacity advantages of the Wanzhou Branch, Southwest Oil and Gas Field Company decided to add a membrane separation oxygen generation unit. The approximately 40% oxygen-enriched air would be mixed with air from the main blower to achieve 26% oxygen content, replacing the original compressed air entering the sulfur recovery unit, thereby reducing the process gas pressure in the sulfur recovery unit and improving its processing capacity. This is also known as the "Oxygen-Enriched Claus" technology. After the transformation, the unit's daily production increased by 100,000 cubic meters, and daily sulfur production rose by 3 tons.

The "Oxygen-Enriched Claus" technology is the first application in the natural gas purification field. Facing challenges such as high corrosion and leakage risks in high-sulfur purification unit equipment and pipelines, frequent equipment failures, high safety risks, and difficult on-site risk control, Southwest Oil and Gas Field Company accurately assessed the transformation project, construction nodes, and technical capabilities. They adopted synchronous construction of project transformation and unit overhaul, established a dedicated team for project execution, and promoted efficient project implementation. They established a "dual-track parallel" supervision mechanism, combining "smart helmet + video surveillance + gas detection" intelligent system with cross-departmental joint inspections to strictly control on-site operation safety risks. Through full-cycle support from the "Technical Management Team", construction quality and progress were ensured. The transformation was completed one month ahead of schedule and successfully commissioned at the first attempt, winning valuable time for more fully releasing production capacity.

Moving forward, Southwest Oil and Gas Field Company will continue to optimize the operation mode of oxygen-enrichment units and sulfur recovery units, while strengthening high-sulfur technical experience总结 and scientific research, providing technical experience support and reference for unit optimization and similar purification plants.