Abstract The majority of wells today are drilled and completed conventionally. That is, they are drilled with kill-weight fluids which may or may not be detrimental to the formation. Wells that are drilled underbalanced, with less-than kill-weight fluid, foam or air, are often exposed to damaging fluids during completion operations. Technology new to the industry or currently being developed will help eliminate these problems and allow for a true underbalanced operation. This technology includes two-stage drilling, downhole lubricators, downhole swab valves, and isolation equipment used in fracturing operations. This paper addresses these issues and the importance that they play in a successful underbalanced completion.