China's first industrial carbon capture project for tail gas from a natural gas processing plant has commenced operation

Recently, the first domestic CCUS-EGR pilot project—Wolonghe Gas Field Maokou Formation Gas Reservoir CCUS-EGR Pilot Project (imported branch)—successfully commenced operations under the general contracting of the Southwest Branch of China National Offshore Oil Engineering Co., Ltd.'s Engineering Construction Company. This achievement marks a significant milestone in the low-carbon development of oil and gas resources through technological innovation and efficient construction.

This project is the first industrial-scale carbon capture initiative for tail gas from a domestic natural gas purification plant, as well as the first demonstration project in China that utilizes carbon dioxide for reinjection and gas displacement. Its carbon capture unit is the nation's first low-pressure, medium-to-low concentration carbon capture system.

To precisely address the core challenges of "low pressure, low concentration, and complex composition" in project feed gas, the Southwest Branch established a research and development team. The team conducted performance evaluations on various technologies, including solvent absorption, solid adsorption, and membrane separation. Through multiple internal and external expert discussions and assessments on different solutions' investment, energy consumption costs, and compatibility, the branch ultimately selected a process solution centered on the CPC-3 carbon capture patented technology and proprietary process package, which is independently developed by the branch. Additionally, an innovative combination of "top scrubbing in absorption towers + microvortex separation" was implemented to minimize amine liquid escape, significantly reducing carbon capture costs and equipment energy consumption.

Facing challenges such as tight project schedules, complex interfaces, and simultaneous construction and production, the Southwest Branch thoroughly implemented the "Six Modernizations" development philosophy. Key facilities like carbon capture and molecular sieve dehydration were designed into seven skid-mounted modules, adopting a "factory manufacturing + on-site deep prefabrication" model to enable parallel progress in civil works and equipment installation. By leveraging a self-developed material control platform to oversee the entire process, nearly 20,000 tons of welding work was completed efficiently, saving 30% of the schedule compared to traditional methods. For the transportation challenges of ultra-large and overweight three-tower modules, multiple site surveys and coordination for oversized permits ensured the smooth delivery of core equipment.

The successful commissioning of this project has explored a low-energy, low-cost key pathway for carbon capture, facilitating the introduction of a subsidiary plant in Southwest Oilfield to achieve the goals of carbon source recycling and zero emissions. Moving forward, the Southwest Branch will continue to conduct research on technological innovation across the entire industrial chain in the CCUS sector, optimize and upgrade carbon dioxide capture technologies, deepen the lifecycle management of carbon capture, and support the high-quality development of China's CCUS industry.