China Classification Society (CCS), a member institution of ICNAME, has announced its successful involvement in the offshore installation of the jacket structure for the Dongfang 1-1 Gas Field Carbon Capture, Utilization and Storage (CCUS) Project in the South China Sea. The achievement marks another important milestone in China's development of large-scale offshore carbon storage technologies and demonstrates the growing role of classification societies in supporting innovative marine engineering projects.

The Dongfang 1-1 project is China's first offshore demonstration project integrating carbon dioxide reinjection with enhanced natural gas recovery. It aims to establish an integrated system for capturing, purifying, compressing and reinjecting carbon dioxide produced during natural gas extraction.

By injecting the captured carbon dioxide into underground gas-bearing formations, the technology can both reduce carbon emissions and improve natural gas recovery, providing a promising approach to the sustainable development of mature offshore gas fields.

Advanced Offshore Platform Design and Installation

The offshore facilities incorporate a large central processing platform and a specially designed steel jacket foundation. According to project information released by China National Offshore Oil Corporation (CNOOC), the jacket features an eight-leg configuration with 12 skirt piles, stands 77.2 metres high, and has an installation weight of nearly 8,000 tonnes.

The installation presented significant engineering challenges because of the complex marine environment, densely distributed offshore facilities and existing subsea pipelines around the Dongfang 1-1 Gas Field.

To address these challenges, the project team optimized the jacket launching and wet-towing procedures and moved the upending operation to an open-water area. Three-dimensional simulation and continuous measurement and monitoring were applied to control the jacket's position, orientation and installation accuracy.

CCS Provides Technical Assurance for Critical Marine Operations

During the offshore installation, surveyors from the CCS Hainan Branch provided on-site inspection and technical assurance services throughout the critical construction stages.

Their work covered the jacket's launching and wet towing, offshore upending, positioning, pile installation and other important marine operations.

By closely monitoring operational conditions and construction safety requirements, CCS contributed to the accurate installation of the jacket and provided technical support for subsequent leg-mating unit installation.

CCS will continue providing inspection services during the installation of the platform's topside modules, equipment commissioning and preparation for operation.

Supporting Offshore Carbon Capture and Storage

The Dongfang 1-1 CCUS platform is designed to integrate carbon capture, purification, storage and enhanced gas recovery into a comprehensive offshore engineering system.

The central platform incorporates an innovative natural gas decarbonization process combining low-temperature distillation and membrane separation. According to CNOOC, the technology is designed to reduce energy consumption by approximately 20% compared with conventional decarbonization methods while improving natural gas recovery by more than 12%.

Once the project is fully operational, it is expected to store more than one million tonnes of carbon dioxide annually in underground geological formations.

The project will provide valuable engineering experience for future large-scale offshore CCUS applications and could support the development of integrated carbon management infrastructure across offshore oil and gas fields.

For the international naval architecture and marine engineering community, the project highlights important technological developments in offshore structural engineering, heavy marine transportation and installation, subsea foundation construction, digital simulation, and carbon management technologies.

The participation of ICNAME member China Classification Society demonstrates the importance of independent technical assurance and international classification practices in enabling safe and reliable offshore engineering innovation.

As the maritime and offshore energy industries accelerate their transition toward lower-carbon operations, projects such as Dongfang 1-1 will contribute valuable technical knowledge to the development of sustainable ocean engineering infrastructure.

Original Source: China Classification Society (CCS)

Original Author: China Classification Society (individual author not specified)

Original Link: https://www.ccs.org.cn/ccswz/articleDetail?id=202611110970148016