Attempts to 'top kill' last year's oil spill in the Gulf of Mexico by ramming mud down the well may have failed because of the unsuitable properties of the drilling mud used.

Credit: LAWRENCE LIVERMORE NATL LABORATORY

Using coloured water and mineral oil, Jonathan Katz of Washington University in St Louis, Missouri, and his colleagues show that the outrushing oil may have broken up the incoming column of mud into small droplets (pictured left, in green). They also show that future wells could be killed more easily by using material that becomes stiff when stretched rapidly — in this study, water with added corn starch (right). This would allow the mud to travel down the well as a slug — without getting churned up — and form a seal.

Phys. Rev. Lett. 106, 058301 (2011)