After over 40 years of exploration, 8 years of design planning and more than a year of construction, the Wushi 23-5 oilfield cluster officially commenced production on July 1.
The Wushi 23-5 is China's first fully green-designed offshore oilfield, pioneering a shallow-water oil and gas sea-land coordinated development model that harmonizes green development with enhanced reserves and production.
Promoting sustainable marine development
During this year's closed fishing season in the Beihai Sea, the Zhanjiang subsidiary of China National Offshore Oil Corporation (CNOOC) carried out large-scale fishery resource compensation and stocking, releasing a total of 114 million fish fry at the public wharf in Tieshan port, Beihai city.
In Bohai Bay, home to China’s largest crude oil production base, the Bohai Oilfield, one construction is in full swing on a shore power project that represents a significant shift in the energy consumption structure of offshore oilfields. Shore power provides clean energy directly to offshore oil and gas fields. Once the third phase of the project is complete, it will create a power network encompassing dozens of oilfields in Bohai Bay, covering over 75 percent of offshore production facilities and reaching a total scale of 980 megawatts.
In parallel with shore power, CNOOC is advancing the intelligent construction of offshore oilfields. The Qinhuangdao 32-6 Operating Company is utilizing digital and information technology to establish an “Ocean Environment Online Monitoring System”, enabling real-time monitoring of the marine environment in operational areas. This system achieves effective linkage between marine ecological monitoring and management, making the marine environment and underwater biological resources “visible, measurable, controllable, predictable and assessable”.
Beyond oil production, offshore oilfields often generate associated gas, water and solid waste. CNOOC has taken measures to harness the energy conservation and carbon reduction potential of these byproducts while protecting the marine environment.
In 2023, CNOOC executed 12 key flare recovery projects, reducing natural gas venting by 970,000 cubic meters per day – equivalent to an annual reduction in carbon emissions of 410,000 tons. By enhancing the recovery and utilization of associated gas, CNOOC has minimized the flaring and venting of this gas in offshore oilfields.
For production water treatment, the Bohai Oilfield has achieved "zero discharge" by reinjecting all production water from offshore facilities. In the Beibu Gulf, strict limitations have been placed on new sewage discharge outlets into the sea, with all production water from new oil and gas field development projects being reinjected into the formation, thus increasing production without increasing pollution. The Lufeng Oilfield Operation Area, particularly the Lufeng 15-1 platform, has been actively promoting production water reinjection, using treated water from the platform as a source, with water quality meeting standards.
CNOOC has also made notable progress in the comprehensive treatment of solid waste generated in oilfields. Through independent research and development, the company has established a technology system for reducing and utilizing drilling waste as a resource. In relevant operational sea areas, CNOOC has successfully recovered and treated over 300,000 tons of water-based drilling waste and over 100,000 tons of oil-based drilling waste, achieving a source reduction of more than 200,000 tons.
Transitioning to a green and low-carbon development model
On July 12, at the bustling port of Ningbo, China’s first liquefied natural gas (LNG) bunkering vessel Haiyang Shiyou 302 was engaged in ship-to-ship bunkering operations, with a maximum bunkering speed of 2,000 cubic meters per hour.
In 2023, China’s LNG imports exceeded 30 million tons, accounting for 44 percent of the nation’s total imports. As the largest LNG importer in China, CNOOC continues to strengthen gas storage capacity, and actively develops the "Natural Gas+" industry and technology model.
In the Yellow River basin regions of Shanxi and Shaanxi, CNOOC’s Zhonglian Company uses zoning and grading methods for development and management, establishing an operational red line control area within a kilometer of the Yellow River channel and main stream shorelines, and a yellow line elevated management area within one to two kilometers. This approach prioritizes ecological protection while optimizing the layout and creating a green foundation for the high-quality development of large onshore unconventional gas fields.
The refining and chemical sectors within CNOOC are also working towards low-carbon development. CNOOC Refining and Chemical is accelerating research and development of high-end chemical products and new materials, and deepening the characteristic utilization of high-quality naphthenic crude oil resources. In 2023, through full-chain energy-saving and carbon-reduction management, it achieved an 89 percent year-on-year increase in carbon reduction.
At Huizhou Petrochemicals, the largest energy-saving low-temperature heat utilization project in China’s petrochemical industry was successfully implemented. Additionally, CNOOC Chemicals, together with the Shenzhen Institute of Advanced Technology of the Chinese Academy of Sciences, established the "Carbon Neutrality and Food Security Interdisciplinary Innovation Joint Laboratory", and launched 106 comprehensive energy stations.
Accelerating the construction of a new energy system
In March 2024, CNOOC won two OTC Technology Awards at the Offshore Technology Conference (OTC Asia), one of which was a major technological innovation from China’s first offshore carbon sequestration demonstration project. This marked the first time in the 10-year history of OTC Asia that a Chinese company had received an award.
In the area of marine carbon reduction and sequestration, CNOOC has developed a new cementing system to address the severe corrosion of wellbore cement rings caused by supercritical carbon dioxide carbonation and acidification. This system acts as a "permafrost cap" for carbon dioxide sealed underground.
In January this year, CNOOC spearheaded the signing of a joint research agreement for the Daya Bay CCS/CCUS Cluster Demonstration Project. It represents China’s first offshore million-ton CCS/CCUS cluster demonstration project.
In the same month, China’s first deep-sea floating wind power platform, Haiyou Guanlan, was listed as one of the top 10 landmark achievements in national oil and gas exploration for 2023. As of July 31, the platform had generated 16.25 million kilowatt-hours of electricity.
CNOOC is intensifying efforts in core technology research for hydrogen production by electrolysis of seawater, advancing the "Key Technologies for Offshore Hydrogen Energy Engineering" project, with breakthroughs in megawatt-level equipment for hydrogen production by electrolysis of seawater. The journey towards "turning water into hydrogen" has begun.
In recent years, CNOOC has continuously invigorated "green finance," with green electricity transactions showing significant growth. In 2021, CNOOC's green electricity substitution reached one million kilowatt-hours, which increased to 300 million kWh in 2022, and to 1.05 billion kWh in 2023, ranking among the top central energy enterprises in green electricity consumption.
(Executive editor: Zhu Zeya)
