A drillship has greater mobility and can move quickly under its own propulsion from drill site to drill site in contrast to semi-submersibles and jackup barges and platforms.

However, they did recommend tighter regulations and closer monitoring of drilling sites using hydraulic fracturing.

One industry-sponsored report said each drilling site could require 31,288 lorry movements over two decades.

The incident spawned a generation of safety regulations that require the industry to designate hazardous drilling targets as critical wells and to use elaborate safety precautions at the drill site.

It will call for a 'one-stop shop' approach that would allow approvals for drilling sites rather than individual wells, as explorers often drill up to 20 wells at one location.