Petroleum System Analysis for a Back-Arc Basin Offshore South Korea - The Ulleung Basin

This petroleum system analysis of the Tertiary Ulleung Basin off-shore South Korea is part of the Korea National Oil Cooperation (KNOC) active exploration program. The basin displays only one producing gas condensate field and several gas/condensate shows. The basin is part of the Miocene East Sea back-arc basin formed at the margin of the Eurasian plate (Tamaki & Honza, 1985) with a Miocene shelf, slope and deep basin environment during the opening and subsidence stage and a following complex compressional and wrenching episode forming the present day back-arc basin. <br>The timing of the development of these compressional structures as traps in relation to the timing of hydrocarbon generation, migration and trap formation is a principal factor in the understanding of the behaviour petroleum system of the Ulleung Basin.<br>This petroleum system study allowed understanding and evaluation of the main features of the petroleum system, as the thermal regime reconstruction related to the tectonic phases, origin of the observed gas-condensate accumulation in relation to the hydrocarbon kitchen and migration pathways, the efficiency of source rocks, interest of the different play concepts in relation to overpressure barriers, migration pathways and prospect assessment.