The installation of China's first offshore ultra-high temperature and ultra-high pressure gas field production platform has been completed, with an annual output of 600 million cubic meters!

Recently, the offshore installation work of the production platform for Ledong 10-1 gas field has been successfully completed. The Ledong 10-1 gas field is the first offshore ultra-high temperature and high pressure gas field that has been identified as a key focus of research and development in China. It is located in the Yinggehai Basin, 113 kilometers away from Sanya City, Hainan Province.

Speaking of basins, there are four basins in the western area of the northern continental shelf of the South China Sea, namely, Beibu Gulf, the Pearl River Estuary, Qiongdongnan, and Yinggehai. The first three basins are widely favored, and only Yinggehai Basin is ignored. Previously, China National Offshore Oil Corporation (CNOOC) failed to sign a cooperative exploration contract in three rounds of external bidding. Because more than 30 foreign oil companies have conducted research on it and unanimously believe that the Yingge Basin has no good mining value. Chinese experts hold the opposite view on this matter. Because as early as the 1950s and 1960s, oil and gas seedlings and crude oil were discovered in the Yinggehai Basin. After entering the 1990s, oil and gas resources were further discovered, demonstrating good exploration prospects.

In 2015, China discovered the Ledong 10-1 gas field in this project, with a proven geological reserve of nearly 18 billion cubic meters. The reservoir temperature of the gas field is as high as 214 ℃, with an average operating depth of about 90 meters and a formation pressure of 94 megapascals, meeting the standards for ultra-high temperature and ultra-high pressure gas fields, making it the first offshore gas field in China.

The development project of Ledong 10-1 gas field follows the development strategy of "overall deployment, step-by-step implementation, and early testing". A new unmanned wellhead platform with 4 legs and 8 skirts will be built, equipped with high-temperature and high-pressure oil and gas extraction equipment. It will be connected to the central platform of Ledong 22-1 gas field through submarine cables and gas pipelines to obtain power supply and oil and gas processing capabilities. After the project is put into operation, the peak annual production is nearly 600 million cubic meters.

The platform installed this time consists of two parts: a production device on the sea surface and an underwater jacket, with a total weight of 9200 tons. The conduit frame is the "base" and was installed using a construction plan of "horizontal construction, towing and loading, lifting and launching, and water filling and straightening". It was fixed on October 5th.

The upper component of the platform installed this time, which weighs over 1900 tons, was lifted by the "Offshore Oil 201" pipeline laying crane to the top of the jacket, then slowly lowered and finally completed the docking installation.

The installation process may seem very simple, but in reality, it is not. You should know that the environment at sea is unpredictable, and platform installation is greatly affected by adverse weather and underwater currents. And during the operation, the weight and height of the jacket approached the capacity limit of the crane vessel. For this purpose, the project team customized a five level construction plan, optimized the construction process, adopted the bow top flow operation mode to overcome the influence of ocean currents, and completed the bottom positioning of the jacket within the 75 hour limit operation window. At the same time, by finely controlling the ship's dynamics in real-time, the precise closure of the upper module and the jacket was achieved, successfully completing this task.

The construction process of the Ledong 10-1 gas field project has broken through the technical limits of multiple offshore oil and gas development, effectively promoting the development process of China's establishment of a technical system for the exploration and development of complex offshore oil and gas resources.

You should know that China has a long coastline and enormous potential for marine energy resources. For example, in 2022 alone, CNOOC has added over 330 million tons of proven geological oil reserves and over 120 billion cubic meters of proven geological natural gas reserves, including major discoveries of billions of tons of oil and gas fields in the hidden buried hills of the Bohai Bay Basin, major discoveries of large-scale natural gas fields in the deep water and deep water exploration of the Qiongdongnan Basin, and major discoveries of large-scale lithological oil and gas reservoirs in the shallow and large areas of the Bozhong Depression of the Bohai Bay Basin The deep water Paleogene exploration in Kaiping Sag, the Pearl River Mouth Basin has made significant discoveries, which has set a new high since the 13th Five Year Plan.

Of course, achieving so many results is closely related to the continuous development of China's comprehensive scientific and technological level. At the same time, in order to extract and utilize these resources more efficiently, it is also necessary to further develop and iterate offshore oil and gas exploration and development technologies. And these have important practical significance for improving China's energy self-sufficiency rate and ensuring national energy security.

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