Avoiding the Blowout

This article elaborates the steps that a driller can take to keep oil and gas secure in a deep seawell. The first step is to use drilling fluid to create hydrostatic pressure in the wellbore to prevent oil and gas from surging up the well. Later, when the well is completed, the wellbore is usually filled with a completion fluid also designed to have a density sufficient to prevent escape of oil and gas from the rock formation. Drilling and completion fluids must be designed in such a way that they do not create excessive hydrostatic pressure. Too much pressure will incur waste because large volumes of the fluids will leak into the rock formations penetrated by the wellbore, where they cannot be retrieved. The next step of preparation is to pump a cement slurry containing various additives through the casing. Once hardened, the cement seals off the oil- and gas-bearing rock from the wellbore until the oil company is ready to produce the well.