China’s first independently developed deepwater subsea Christmas tree has successfully passed a crucial gas tightness test. The test was conducted by Offshore Oil Engineering Co., Ltd., a subsidiary of China National Offshore Oil Corporation (CNOOC).
As a critical component connecting subsea wells to pipelines, the subsea Christmas tree regulates oil and gas production, monitors operations in real time, and ensures safe and efficient extraction. The tested model, featuring a retrievable Flow Control Module (FCM), is China’s most advanced in terms of water depth, pressure rating, and temperature tolerance.
During testing, the system withstood a pressure of 10,000 psi — equal to 690 times atmospheric pressure — with all sealing points performing within standard limits. The test confirmed the reliability of the tree’s composite metal-elastomer sealing structure, designed to adapt to temperature changes and ensure long-term sealing under extreme conditions.
The FCM integrates a multiphase flowmeter and a fixed choke valve into a retrievable unit, enabling efficient maintenance without retrieving the entire system, thus reducing costs. A breakthrough was also achieved in sealing and locking the multi-port connector, a key component of the FCM.
This equipment is a flagship product under the “Qinghai” brand of Offshore Oil Engineering Co., Ltd. Its development has driven innovation across multiple fields and mobilized over 100 domestic suppliers, contributing to the establishment of a comprehensive subsea equipment manufacturing system.
(Executive editor: Wang Ruoting)
