China's First 100-Billion-Cubic-Meter Gas Field Reaches Full Production

A Milestone Beneath the Bohai Sea

CNOOC Tianjin Branch announced on Sunday August 9 2026 that Phase I of the Bozhong 19-6 gas field in the Bohai Sea has reached full production. This marks China's first 100-billion-cubic-meter gas field in the Bohai Sea. Proven geological natural gas reserves exceed 200 billion cubic meters and proven geological liquid petroleum reserves exceed 200 million tons. The field currently produces a daily oil and gas equivalent of more than 5,200 metric tons under Phase I. It stands as the largest offshore gas field in eastern China. The announcement comes after steady progress since initial output began in November 2023. By August 2024 the project had already delivered over 1 billion cubic meters of natural gas. Cumulative production has now surpassed 2.8 billion cubic meters. These volumes add to China's domestic supply at a time when import-dependent nations across the Asia-Pacific continue to monitor shifts in regional spot LNG demand. Japan remains the world's largest LNG importer and any sustained increase in Chinese offshore output could influence long-term procurement strategies in Tokyo and other capitals. Observers note that the Bohai development forms part of broader efforts to strengthen energy security without overstating immediate effects on global prices.

The Engineering Behind 5,000-Meter Reservoirs

The field lies in the central waters of the Bohai Sea at an average water depth of about 20 meters. The reservoir is buried at a depth of over 5,000 meters with complex reservoirs and dense fractures in buried hills. During Phase I workers drilled 10 ultra-deep wells exceeding 6,000 meters depth. This set a record for the number of ultra-deep wells in a single Bohai Oilfield development project. Average drilling depth surpassed 5,500 meters. To date the field has cumulatively produced more than 2.8 billion cubic meters of natural gas. Phase I first began production in November 2023. By August 2024 it had produced over 1 billion cubic meters. These technical achievements reflect incremental advances in offshore drilling under challenging geological conditions. For Japan and other Asia-Pacific economies that rely on imported energy the demonstration of deeper drilling capability in Chinese waters may signal future competition in regional engineering services. At the same time the modest water depth of roughly 20 meters limits direct comparison with harsher environments such as the South China Sea or Australian offshore basins. Analysts therefore treat the Bohai records as one data point rather than a sweeping indicator of dominance in all offshore settings.

What Full Production Means for China's Energy Mix

CNOOC says the milestone is significant for optimizing regional energy structures and supporting local economic and social development. The daily output of more than 5,200 metric tons of oil and gas equivalent under Phase I adds steady supply to eastern China. Cumulative production of more than 2.8 billion cubic meters of natural gas demonstrates the field's contribution to domestic resources. This output helps balance energy needs in a region that has relied on varied sources. China's expansion of offshore gas production could gradually reduce the volume of spot LNG cargoes sought on Asian markets. Japan which imports nearly all of its natural gas in liquefied form watches such developments for any sustained impact on contract negotiations and storage planning. While the Bohai volumes remain modest relative to national consumption they contribute to a wider portfolio that includes pipeline imports and other domestic fields. Cautious observers note that full integration of Phase I output into eastern China's grid will require continued infrastructure investment. The project's role in the national production supply storage and selling system therefore merits ongoing tracking rather than immediate assumptions of large-scale displacement of imports.

Bozhong 19-6 in the Wider Bohai Oilfield

The field forms a critical component of the wider Bohai Oilfield. China's first super-large offshore oil and gas field holds an annual production capacity of 40 million tons. Cumulative oil and gas production there recently exceeded 21 million tons a new high. The addition of Bozhong 19-6 strengthens the overall capacity of the Bohai Oilfield through its Phase I results and ultra-deep drilling achievements. The Bohai complex now combines conventional oil output with substantial gas reserves exceeding 200 billion cubic meters. For energy planners in Japan and neighboring economies the combined Bohai figures illustrate China's determination to raise domestic hydrocarbon production. This effort occurs against a backdrop of fluctuating global LNG prices and evolving long-term supply contracts. The 40 million ton annual capacity target remains an aggregate figure that includes multiple platforms and reservoirs. Phase I of Bozhong 19-6 contributes a measured increment rather than an abrupt leap. Regional gas markets in the Asia-Pacific will therefore register the cumulative effect over several years rather than through any single announcement. Continued reporting on total Bohai output will help clarify the pace of this contribution.

Japan's LNG Calculus and Asia-Pacific Gas Markets

Japan maintains high dependence on LNG imports for energy security in the Asia-Pacific region. The full production at Bozhong 19-6 adds domestic natural gas supply within China and may ease pressure on regional gas markets. Offshore developments like this one in the Bohai Sea highlight shifts in supply dynamics that import-reliant nations such as Japan monitor closely for long-term planning. Tokyo's utilities and trading houses routinely assess Chinese offshore growth when negotiating multi-year contracts with suppliers in Australia Qatar and the United States. An incremental rise in Chinese domestic output could modestly trim spot purchases during shoulder seasons yet the scale of Japan's annual imports exceeds 100 million tons so any single field registers as one variable among many. Energy security strategies in Seoul Taipei and Singapore similarly track these trends. The Bohai milestone therefore enters regional calculations without prompting immediate contract revisions. Analysts emphasize that sustained output growth across multiple Chinese offshore projects would be required before measurable effects appear in Asian spot prices or destination flexibility clauses.

Offshore Engineering Race: What China's Record Wells Signal

The drilling of 10 ultra-deep wells exceeding 6,000 meters in a single project reflects advances in offshore engineering. Average depths surpassing 5,500 meters in the Bohai Sea set benchmarks for similar efforts. CNOOC CEO Zhou Xinhuai has described Bozhong 19-6 as a key project in building China's natural gas production supply storage and selling system. These records indicate growing technical capacity in complex reservoir conditions. Japanese and South Korean offshore contractors have long competed in platform fabrication and subsea equipment supply. The completion of a 12,000-tonne central platform in May 2023 for the Bohai project illustrates one element of that expanding capability. While the ultra-deep well count sets a project-specific record the average water depth of 20 meters remains comparatively benign. Regional engineering competition therefore centers on cost efficiency and repeatability rather than outright depth records alone. Import-dependent economies continue to evaluate whether Chinese contractors will seek greater participation in future LNG-related infrastructure projects across Southeast Asia and Australia.

What to Watch For

Further phases of the Bozhong 19-6 gas field will determine additional output levels beyond the current daily equivalent of more than 5,200 metric tons. Continued integration with the Bohai Oilfield's 40 million ton annual capacity remains a point of observation. Regional energy structures in eastern China and broader Asia-Pacific gas markets will reflect the effects of these cumulative volumes over time. Japan will track whether subsequent phases materially alter its LNG procurement volumes or prompt adjustments in strategic storage targets. The timeline for any additional phases has not been specified in detail so observers await further announcements from CNOOC. In parallel the performance of the 10 ultra-deep wells will provide data on long-term reservoir behavior under the reported fracture conditions. Energy security assessments in Tokyo and other capitals will incorporate these results gradually. The interplay between Chinese domestic output growth and Asian spot LNG demand therefore warrants measured attention rather than short-term conclusions.

By Kenji Tanaka, Staff Writer

This article was produced with AI-assisted research and editorial support. Sources: CGTN, China Daily, Global Times, CNOOC.