DRILLING for oil is unlikely ever to be good for the environment, but there could be way to make it a little greener. That’s the claim of scientists behind a new drilling fluid that they are hoping to test in offshore oil rigs in the South China Sea.
Drilling fluids cool and lubricate oil drills, and help to transport cuttings to the surface. But boreholes can be kilometres deep, and because pressure increases with depth, the fluid can be forced into tiny pores in the clay-rich rocks such as shale and mudstone through which boreholes pass. This destabilises the boreholes,…
