Reliance Industries has chosen Transocean's deepwater drillship 'Deepwater Frontier' to drill on its gas-rich D6 block in the KG Basin for starting commercial production from mid-2008.The US firm will move Deepwater Frontier to the Krishna-Godavari Basin block KG-DWN-98/3 (also known as KG-D6) by next month, company sources said.Reliance has already drilled two developmental wells successfully on Dhirubhai-1 and Dhirubhai-3 gas fields, which it plans to bring to production by July 2008. Deepwater Frontier is to drill 14 development wells. Sources said Reliance would invest $2.49 billion to produce 40 million standard cubic metres gas per day for 7.5 years from a total of 34 development wells.