Korea is surrounded by the Yellow Sea, the East Sea, and the South Sea with extensive continental shelves of 300,000 ㎢ which have the potential for oil and gas exploration. Western oil companies such as Gulf, Shell, and Koam Corporation explored oil and gas in shallow waters in 1970s and 1780s. Since KNOC had been established in 1979, it began working on the shelves continuously and has acquired 116,549 L-㎞ of 2D seismic data and 7,519 ㎢ of 3D seismic data and has drilled 47 wells so far.

In 1998, KNOC discovered a commercially viable gas field in Block 6-1 in the East Sea. The field, which was named Donghae-1, is about 60 ㎞ away from Ulsan in the southern region of Korea. Donghae-1 gas field was on stream in 2004 and has produced gas and condensate so far. In 2014, KNOC initiated Donghae-2 gas project to develop a near field discovery with a single producer which was successfully subsea tie-backed to Donghae-1 platform in 2016.

Korean government has divided the offshore area into 12 blocks(excluding JDZ) and some blocks are currently authorized for licensees to explore. A list of blocks and their status are shown in following table.

A large portion of the surrounding continental shelves consisting of Ulleung, Jeju and Yellow Sea basin has yet to be explored.