The drilling operation for a major resource exploration project in the East Sea has begun. 

The Korea National Oil Corporation(KNOC) said Friday that the work kicked off early in the morning at a site about 40 kilometers from the shores of the southeastern city of Pohang, North Gyeongsang Province. 

The West Capella, a drillship participating in the project, arrived at the southeastern port city of Busan on Monday and reached the first drilling site Tuesday morning.

The KNOC said it expects the drilling operation to take around 40 to 50 days, with the results of the analysis set to be released in the first half of next year. 

KNOC CEO Kim Dong-sub said the drilling operation is significant in that it can verify the presence of oil and gas and help establish the direction of future exploration.

He vowed to spare no effort to complete the operation without disruptions.