ENI VIETNAM has started a seismic study over Block 120 offshore central Vietnam, following the withdrawal of Australia-based Neon Energy from the permit.

Project partner KrisEnergy said Eni had secured the CGG Amadeus vessel to start a 57,000 hectare 3D seismic acquisition program in the acreage in late March, with the survey predicted to take 23 days.

The survey is designed to image the carbonate and basement sections of the Ca Lang prospect and associated leads on the Tri Ton horst – and will tie into a 50,200 hectare 3D seismic dataset acquired in 2012.

The Ca Lang prospect lies about 25 kilometres to the southeast of the location of the Ca Ngu 1 well, which intersected a 20 metre oil and gas column when it was drilled in 2013.

KrisEnergy’s director of exploration and production Chris Gibson-Robinson said the company had carried out detailed analysis of its geological model for Block 120, incorporating data from the Ca Ngu-1 well, over the last 14 months.

“Now our attention is focused on the Ca Lang area and we look forward to being able to more clearly map and further de-risk the prospect, which we believe has a high chance of intersecting hydrocarbons in multiple objectives,” he said.

Block 120 covers 686,900 hectares overlying the Quang Ngai graben and the Tri Ton horst where water depths range from 50 metres to 650 metres.

Eni Vietnam is operator of Block 120 with a 66.67 per cent working interest, while KrisEnergy holds the remaining 33.33%. The companies were issued an amended investment certificate by Vietnam’s Ministry of Industry and Trade following Neon Energy’s withdrawal from the project.

Neon agreed to pay US$5.75 million to the companies, assign its working interests in the blocks and remit proceeds from an insurance claim in exchange for a full release of its liabilities over the blocks in mid August 2014.