China's Highest-Pressure Offshore Gas Well Completed
China National Offshore Oil Corporation (CNOOC) announced that the country's highest-pressure offshore natural gas well - the No. A12 well of the phase II project of Shenhai Yihao, or Deep Sea No. 1 - has completed its drilling operation, marking the conclusion of all offshore drilling and completion work of the project.
The well has tested a daily production of 830,000 cubic meters.
Deep Sea No. 1 is China's first independently-developed and built ultra-deepwater gas field.
Located in the Lingshui area southeast of Hainan Island, the Phase II project is China's pioneering deep-water high-pressure gas field project, operating at depths approaching 1,000 meters. The project features 12 deep-water gas wells, with an average well depth exceeding 5,000 meters.
Jiang Donglei, project manager for the well completion project at CNOOC, detailed the major challenges faced in their operations.
"The greatest challenge in developing deep-water high-pressure gas fields is well completion operations. We must establish a safe transportation channel for deep-sea oil and gas. The Phase II project includes 12 wells with a total depth exceeding 60,000 meters, equivalent to the height of seven Mount Everest peaks. The formation pressure reaches up to 69 MPa, which is 1,000 times the pressure of a household pressure cooker. The technical difficulty of this project is significantly higher than that of Phase I," he said.
The project faces four major world-class challenges: deep water, deep layers, high temperatures, and high pressures, with no precedents globally.
Deep Sea No. 1 which began production in June 2021, has proven geological reserves exceeding 100 billion cubic meters.
The Phase II project is located about 70 kilometers from the energy station of the gas field.
Upon full production, it will increase the gas field's reserves from 100 billion cubic meters to 150 billion cubic meters and its annual production from 3 billion cubic meters to 4.5 billion cubic meters.
