Underbalanced drilling is defined as drilling with the hydrostatic pressure of the fluid intentionally less than that of the formation pore pressure. The IADC classifies UBD wells according to the drilling fluid used to achieve underbalanced conditions.

Keywords:
liquid drilling, underbalanced drilling, lubrication method, ub work, well control, liquid phase, lubrication cycle, quantity, iadc spe 81645, annular pressure drilling
Subjects:
Pressure Management, Underbalanced drilling, Well control
Copyright 2003, IADC/SPE Underbalanced Technology Conference and Exhibition
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