An overview of the Donghae-1 gas field. / Courtesy of Korea National Oil Corporation

The Donghae gas field block, operated by the Korea National Oil Corporation (KNOC) and once a cornerstone of domestic natural gas production and energy security, is transitioning into an abandoned mine system following the expiration of its extraction rights. Consequently, the legal status of the Donghae gas field changes from an active mine to an abandoned one, initiating decommissioning procedures for its production facilities. KNOC, however, has yet to present a distinct roadmap regarding its future decommissioning plans and cost estimations.

According to resource industry sources on July 3, KNOC’s extraction rights for the Donghae gas field (specifically Block 6-1 Central) expired on this day. Initially granted from July 4, 2001, to July 3, 2021, the extraction rights had been extended by five years after the corporation renewed them once in 2021. Since resource production wrapped up at the end of 2021, the Donghae gas field has been operating under an unmanned system since January 2023.

The industry had previously pursued plans to repurpose parts of the gas field platform for offshore wind and carbon capture and storage (CCS) projects. However, the relevant legislation remains stalled in the National Assembly, leaving no legal groundwork for facility recycling. The industry managed to buy some time with the revision of the Enforcement Decree of the Submarine Mineral Resources Development Act on June 30. This amendment extended the deadline for restoring the site to its original state from one year to five years post-expiration, offering more breathing room for the decommissioning schedule.

Under the assumption that the law would be amended, KNOC has been internally reviewing ways to utilize the Donghae gas field’s underground storage spaces, production wells, pipelines, and the lower jacket structures of its offshore platforms for CCS and offshore wind energy. Yet, under current law, reusing these facilities remains restricted, meaning the actual execution hinges entirely on revisions to the Submarine Mineral Resources Development Act. Independent of these legislative shifts, KNOC has not officially disclosed its future management strategies, decommissioning timelines, or estimated costs for the gas field.

Back in 2022, KNOC had estimated the decommissioning costs for the Donghae gas field at 2 million dollars (approximately 3 billion won). Because this figure was calculated four years ago solely for internal accounting purposes, the actual expenses could shift significantly if decommissioning begins now. For context, a total project budget of 1.2 trillion won was injected into the Donghae gas field during its initial development.

                                                                                                         Bae Seok-won