Changes

==Mud weight and pore pressure==

==Mud weight and pore pressure==

The mud weight needed to control a well reflects pore pressure of any permeable formations drilled. To control a well, operators generally use a mud weight that will exert a pressure close to the expected pore pressure. When drilling mud kicks or blows out, the pressure from the mud is less than, but usually close to, pore pressure.

The [[Drilling fluid|mud weight]] needed to control a well reflects [http://www.glossary.oilfield.slb.com/en/Terms/p/pore_pressure.aspx pore pressure] of any permeable formations drilled. To control a well, operators generally use a mud weight that will exert a pressure close to the expected pore pressure. When drilling mud kicks or [[Pressure_detection#Drilling_problems_with_overpressured_reservoirs|blows out]], the pressure from the mud is less than, but usually close to, pore pressure.

==Calculating pressure from mud weight==

==Calculating pressure from mud weight==