Kongsberg Maritime, COSL Drilling Europe AS and drilling equipment provider NOV have developed a green solution, achieving a 25% overall saving in fuel and emissions in offshore drilling operations.
The technology builds on the ‘Energy Control’ project, launched earlier by COSL as a means of simultaneously slashing greenhouse gas emissions and lowering fuel and maintenance overheads on the company’s rigs situated on the Norwegian shelf in the North Sea.
The company now called upon the technological knowledge of Kongsberg Maritime and the specialist knowledge of NOV to take these aspirations to the next level.
Analysis of historical data on estimated maximum power consumption derived from COSL’s semi-submersible DP3 rigs COSLPromoter and COSLInnovator revealed that it would be possible to make changes that removed the need to run all six of its 4,800kW Wärtsila Vasa 12V32 diesel during drilling operations.
Kongsberg Maritime used the estimates to develop means of controlling onboard energy production and distribution. A core principle of the joint solution was to limit and optimise generator usage, and it was soon established that the rig would still be able to carry out full drilling operations using only three of its diesel generators, on average.
The annual figures, as a result, reveal that fuel consumption would be reduced by around 2,300 tonnes, CO2 emissions by 7,300 tonnes and NOx by 125 tonnes, equating to an overall saving in fuel and emissions of more than 25%.
We can now accomplish complete drilling operations on COSLPromoter and COSLInnovator while using less than 20 tonnes of fuel per day, with scope to reduce that figure even further. We also have the reassurance of knowing that the spare generators are on hand should any changes in conditions or circumstances require them to be used,
…says COSL project leader Torfinn Kalstø.
The project is approved and supported by the NOx Fund, a Norwegian Government initiative for reducing NOx emissions.
