Today (March 12), a CCTV reporter learned from CNOOC that China’s first domestically designed and built ultra-deepwater jacket platform—the “Haiji No. 2”—has been completed in Zhuhai. The project has set new Asian records in structural height, weight, operating water depth, and construction speed, marking a significant milestone: China’s capability for the independent design and construction of ultra-large deepwater jacket platforms has now reached world-leading levels.

Construction of “Haiji-2” Completed; Offshore Installation to Begin at End of March

Fixed jacket platforms are critical assets for offshore oil and gas development, comprising an underwater jacket, pile legs, and an above-water production module. The jacket serves as the “foundation,” ensuring the stability and safety of the entire offshore oil and gas platform. The “Haiji No. 2” jacket stands 338.5 meters tall and weighs a total of 37,000 metric tons, with steel consumption comparable to that of the National Stadium—the “Bird’s Nest.” Given the frequent typhoons and extremely severe wind waves and internal wave currents in its operating waters, this jacket was designed to withstand once-in-a-century extreme marine conditions.

Shu Wei, General Contracting Project Manager for the Liuhua Oilfield at CNOOC Engineering: We have innovatively proposed an “intelligent jacket platform” design and construction solution, which has not only significantly enhanced China’s capabilities in intelligent monitoring and digital operations and maintenance of deepwater jacket platforms, but also, through independent technological breakthroughs, enabled us to fully master the complete set of proprietary design and construction technologies for jacket platforms in water depths exceeding 300 meters.

With the continuous development of offshore oil and gas resources, water depths exceeding 200 meters have become a critical frontier for China’s offshore oil and gas exploration and production. The successive completion of deepwater jacket platforms such as “Haiji No. 2” has further underscored the growing importance of the jacket platform development model in China’s deepwater oil and gas exploitation.

Wang Huoping, Executive Deputy General Manager of the Liuhua Oilfield Development Project Team at CNOOC Shenzhen Branch: For the first time, we have extended the operational water depth of jacket platforms to over 300 meters. This not only significantly reduces development investment, construction costs, and production expenses, but also makes it feasible to develop a large number of potential marginal deepwater oilfields, thereby opening up a new pathway for China’s efficient exploitation of oil and gas resources in its mid-to-deepwater offshore areas.

According to reports, the “Haiji-2” project is scheduled for offshore installation at the Liuhua Oilfield—the country’s first deepwater oilfield located in the Pearl River Mouth Basin—by the end of March.

Pushing Operational Limits: Further Upgrading Deepwater Oil and Gas Equipment

As offshore oil and gas exploration advances into deeper waters, jacket structures—key support systems for offshore platforms—are confronting significant technical challenges. During the construction of the “Haiji No. 2” jacket, a wide array of advanced technologies were employed, successfully pushing the operational limits of deepwater oil and gas equipment and providing robust technical support for China’s move toward deeper and more remote offshore oil and gas development.

The operational waters for the “Haiji No. 2” jacket platform have an average water depth of approximately 324 meters. This depth not only leads to a sharp increase in environmental loads but also amplifies the impact of adverse sea conditions such as internal wave currents and typhoons. Under conventional design practices, the jacket’s launch weight would reach 42,000 metric tons—a figure that exceeds the load-carrying capacity of existing fabrication yards and construction vessels both domestically and internationally.

Fu Dianfu, Deputy Director of the Engineering Research and Design Institute of CNOOC Research Institute: The project team collaborated with domestic steel enterprises to jointly develop 420 MPa-grade ultra-high-strength thick steel plates tailored for offshore engineering applications. The adoption of this innovative material has not only overcome key technical challenges in the lightweight design of ultra-large offshore platforms, resulting in a successful weight reduction of 5,000 tonnes for the “Haiji No. 2” jacket platform and generating cost savings of over RMB 100 million in materials and vessel modification expenses, but also paved the way for the large-scale application of domestically produced high-strength steel in offshore engineering.

In addition to material innovations, the “Haiji No. 2” platform has, for the first time worldwide, deployed a tensioned impressed-current cathodic protection system on a 300-meter-class jacket structure. This technology significantly enhances the corrosion resistance of deepwater jacket platforms. Meanwhile, the project team has independently developed multiple intelligent sensing and monitoring systems—covering structural stress monitoring, environmental load monitoring, and deep-sea internal wave and current monitoring—enabling real-time, intelligent monitoring of the jacket’s condition throughout its service life and facilitating digital operations and maintenance management. These advancements have substantially improved the safety and efficiency of offshore operations.

Wang Minfeng, Construction Manager of CNOOC’s “Haiji No. 2” Platform: In recent years, China has successively commissioned several deepwater jacket platforms, including “Haiji No. 1” and Lufeng 12-3, thereby progressively establishing a comprehensive system of deepwater jacket design, construction technologies, and management. With the completion of the “Haiji No. 2” project, China’s capability for the independent design and construction of ultra-large deepwater jacket structures has reached world-leading levels.

Innovating Development Models to Advance the Oil Industry into Deep and Far-Off Seas

The “Haiji No. 2” adopts an innovative development model that integrates a deepwater jacket platform with a cylindrical offshore oil and gas processing facility, achieving new technological breakthroughs and industrial upgrading, and thereby driving the steady expansion of the petroleum industry into deep and ultra-deep waters.

“Haiji No. 2” is China’s first jacket platform deployed in waters deeper than 300 meters. Upon completion of its installation, the platform will stand in deep water at a depth of 324 meters, working in tandem with Asia’s first cylindrical “offshore oil and gas processing facility” to jointly develop China’s first deepwater oilfield—the Liuhua 11-1 field—capable of processing nearly 5,600 metric tons of crude oil per day.

Jiang Junda, General Manager of the Liuhua Oilfield, Shenzhen Branch of CNOOC: The “deepwater jacket platform plus cylindrical ‘oil-and-gas processing plant’” development model, compared with the conventional all-subsea production system, not only reduces development costs and ensures independent, controllable technology but also significantly enhances oilfield recovery rates. It is estimated that oilfields developed using this new approach could see their economically viable production life extended by nearly 30 years.

Over the past decade, 70% to 80% of new oil and gas discoveries worldwide have been made in offshore areas, with nearly two-thirds concentrated in deepwater regions. China’s exploration and development of deepwater oil and gas resources remain in the early stages, offering broad prospects for increasing reserves and boosting production.

Currently, CNOOC has independently developed more than a dozen oil and gas fields in China’s deepwater areas, including “Deep Sea No. 1,” “Haiji No. 1,” and “Liuhua 16-2,” with an annual output exceeding 10 million tonnes. Its exploration and development capabilities have made a major leap from operating in water depths of 300 meters to 1,500 meters, and it has progressively mastered various deepwater oil and gas development models.

(CCTV reporters Zhang Wei, Zhang Congjing, and Qu Baiyu)