دیکشنری تخصصی مهندسی نفت - نسخه آنلاین

n: The amount of pressure (or force per unit area) exerted on a formation exposed in a wellbore below the internal fluid pressure of that formation. If sufficient porosity and permeability exist, formation fluids enter the wellbore. The drilling rate typical

when the pressure exerted by the column of fluid in the wellbore is less than the pore pressure in the formation.