Deepwater drillship. A drillship is a maritime vessel used for exploratory offshore drilling of new oil and gas wells, or for research purposes. A drillship can be used as a platform for carrying out well maintenance work, installations and well capping. This vessel is the Deepwater Asgard photographed off Cape Town, South Africa in January 2015. It was built in South Korea and entered service in 2014. Its maximum drill depth is more than 12,000 metres.