Underbalanced drilling has been receiving attention in the industry because of the benefits gained from its application. It has been successful in most drilling operations and has become one of the most effective and favorable drilling techniques amongst operators. The reason for this is its ability to overcome various drilling and production problems encountered in conventional drilling such as loss of circulation and formation damage. Such problems can subsequently lead to the loss of profit and this has prompted further research over these years to develop a better technique to improve production in various reservoir characteristics. It is a challenging feat to accomplish a constant underbalanced condition throughout the drilling operations and hence, is oneof the major drawbacks that is difficult to overcome.