Chinese yard China Merchants Heavy Industry has achieved mechanical completion of a deep-water semi-submersible drilling rig built for Chinese drilling contractor China Oilfield Service Ltd (COSL) for operation in the South China Sea.

The mechanical completion will mean that the rig is to sail away early next year for the South China Sea, for a campaign in the deep-water Qiongdongnan basin or Pearl River Mouth basin after final system tuning at the yard in Haimen in eastern China’s Jiangsu province.

The rig – now named Deepblue Explorer, which is of CM-SD1000 design – was launched at the end of February this year after first steel was cut in October 2018.

The unit, which has a mooring system rather than dynamic-positioning system, has a drilling system provided by Dutch company Huisman.

Drilling sources said there is a chance the new unit will replace an existing ageing semisub — possibly the Nanhai 5.

The new rig is equipped to raise drilling efficiency by 30% and is suited for operation in the South China Sea, Gulf of Mexico, Middle East and West Africa in water depths of between 300 and 1000 metres.

Nanhai 5, which has already reached retirement age, is understood to have been sold to CMHI but is currently being chartered by COSL on a three-year contract for operations in the South China Sea that started in 2018.

The rig, delivered in 1984 and originally designed to have an operating life of 33 years, was overhauled at CMHI's yard in Shenzhen early in 2018.

Rigs And Vessels

COSL’s brand new deep-water semisub soon to start drilling campaign in South China Sea