top kill

A procedure used as an attempt to stop an oil well from leaking. In the top kill procedure, large quantities of a fluid known as drilling mud is pumped into the well at very high pressures. In order to stop the leak, the pressure of the mud needs to be greater than the pressure exerted by the leaking oil. If the drillers are able to accomplish this, it should stop the oil leak, and then cement would be pumped into the well to further block the leak. This procedure is relatively standard in above-ground oil well disasters, but is used very infrequently in underwater oil leaks. Most notably, this procedure was recently attempted in the aftermath of the 2010 BP oil spill, but due to many complications including the water depth and the oil pressure, the top kill technique was not successful.