On April 15, 2021, China National Offshore Oil Corporation (hereinafter referred to as CNOOC) announced that China’s first 100 billion cubic meters of self-operated deep-water large gas field "Deep Sea No. 1" gas field (Lingshui 17-2 gas field) all development wells All the drilling and completion operations of the gas field have been completed, laying a solid foundation for the smooth commissioning of the gas field. CNOOC said that this once again verified the advanced nature and reliability of the complete set of deep-water oil and gas field development drilling and completion technology systems that China has independently mastered, and it indicates that China has fully equipped with deep-water and ultra-deep-water oil and gas exploration and development capabilities.

Difficult to develop

The "Deep Sea No. 1" gas field is located in the Qiongdongnan Basin 150 kilometers away from Hainan Island. It was discovered by CNOOC in 2014. The proven natural gas reserves exceed 100 billion cubic meters. The maximum water depth exceeds 1,500 meters, which is equivalent to the altitude of Mount Tai. The maximum well depth is more than 4,000 meters. It is the deepest offshore gas field with the deepest average water depth and the most difficult exploration and development that China has discovered so far.

The "Deep Sea No. 1" gas field was developed using the "semi-submersible production platform + underwater production system" model. A total of 11 development wells were deployed in 7 deep water well areas with a span of more than 50 kilometers from east to west, facing large operating water depths and differences in well area conditions. There are many challenges such as severe weather and frequent extreme weather, and there are few successful cases of the same type of operation in the world that can be used for reference. "The completion of drilling and completion operations is a key link in the commissioning of a gas field. We find oil and gas from the deep sea and establish a transmission channel. Only clean energy from the deep sea can be transported to thousands of households." CNOOC "Deep Sea No. 1" gas field development Liu Hexing, the person in charge of the drilling and completion project, told reporters. At present, the "Deep Sea No. 1" gas field production pipeline has been connected to the Hainan Island's submarine clean energy supply network. After the gas field is put into production, it will become the main gas field that guarantees the energy supply for the construction of the Hainan Free Trade Port and the Guangdong-Hong Kong-Macao Greater Bay Area. It will provide a steady supply of 3 billion cubic meters of gas to Guangdong, Hong Kong and Qiong every year.Editor/XuNing、Design/WangXia