The first exploratory drilling to confirm whether oil or gas is buried in the gas prospective structure dubbed 'Great Whale' in the East Sea has been completed. Some gas traces were detected at the drilling site; however, the scale was minimal. The Ministry of Trade, Industry and Energy and the Korea National Oil Corporation (KNOC) have concluded that the Great Whale prospective structure is not economically viable. The government plans to push for drilling in other promising structures estimated to have gas reserves by attracting investments from oil majors in the future.
According to the Ministry of Trade, Industry and Energy and the Korea National Oil Corporation (KNOC), the drilling work for the Great Whale prospective structure, which started on Dec. 20 last year, was completed on 4th. The drillship West Capella, which was in charge of the drilling, finished its 47-day operation and departed from Busan Port on the 5th.
The Korea National Oil Corporation (KNOC) plans to send the verification data and samples obtained during this drilling process to a specialized service company for detailed analysis. This precise analysis is expected to take about six months. The detailed analysis work will be conducted by a different geological structure specialist, not 'ActGeo', who raised the possibility of deep-sea gas fields in the East Sea. The precise analysis is scheduled to conclude after August; however, the government and the Korea National Oil Corporation (KNOC) plan to announce the interim analysis results around May to June.
According to the Ministry of Trade, Industry and Energy, a 'petroleum structural system' that could contain oil or gas has been confirmed in this Great Whale prospective structure. A 'trap structure' consisting of source rocks where oil is generated, reservoir rocks where oil accumulates, and cap rocks that prevent the oil from leaking out has been identified, with the thickness of the structural layer being thicker than expected, a senior official from the Ministry noted.
Hydrocarbons in the geological layer have also been confirmed. However, the gas saturation level within the hydrocarbons appeared to be insufficient. A senior official from the Ministry stated, "We cannot announce the exact gas saturation values as the precise analysis has not yet been completed," but added, "It fell far short of what could be deemed economically viable."
Regarding the low gas saturation levels within the hydrocarbons, it was stated, "We cannot know. The reservoir layer was quite favorable. Although a trap structure with cap rocks was confirmed, there are various possibilities, such as whether there were fissures in certain areas allowing gas to escape or if the hydrocarbons passed through the structure. We need to wait for the precise analysis results."
The government believes that the likelihood of finding commercially viable amounts of oil or gas in the Great Whale prospective structure is low, and from the second drilling onward, it has decided to proceed with exploration of other promising structures.
The target promising structure for the second drilling has not yet been determined. The site for the second drilling is expected to vary based on the results of attracting foreign investments. A senior official from the Ministry said, "In the investment attraction process, we found that corporations have slightly different perspectives," adding, "The areas will be determined based on the companies' intentions during the investment attraction process, and exploration drilling will proceed based on the judgment of the investing corporations."
The Korea National Oil Corporation (KNOC) is set to begin overseas investment attraction efforts for deep-sea gas fields starting next month. A representative from the Korea National Oil Corporation (KNOC) stated, "We are preparing so that the investment attraction procedures can be fully initiated with global corporations that possess the capital, technology, and experience necessary for deep-sea development," and said, "We plan to issue an investment bidding notice by the end of March at the latest."