Fadhel previously held the title of undersecretary at the Ministry of Commerce, and was a professor at Kuwait University's Faculty of Engineering and Petroleum.
Fadhel was not immediately available for comment.
Kuwait's cabinet earlier accepted the resignation of Fadhel's predecessor, Bakhit al-Rashidi, according to al-Qabas newspaper.
Rashidi's departure is unlikely to imply any change in Kuwaiti oil policy, which is decided by the country's Supreme Petroleum Council.