Underbalanced (UB) drilling is becoming an important tool for developing producing horizons in underpressured reservoirs, partially depleted fields, new fields, and sensitive zones. This technique is being used to maximize producing potential in fields similar to those found in some areas of the
A important aspect of UB success is reservoir screening. Basic screening criteria from readily available data, as well as results of applying this technique to the
In addition to improving well productivity by reducing formation damage, there are many significant reservoir–related uses of UB emerging. These uses include reservoir characterization, net pay evaluation, exploration and appraisal.