Field results document underbalanced drilling success

Many different techniques are used to maintain underbalanced conditions at the toolface. Whether the operator is trying to avoid drilling problems or prevent formation damage, the key to a safe, successful operation is a reliable method of sealing around the tubulars at the surface for continuous well control. Globally, underbalanced drilling (UBD) is emerging as an important technology to improve production and solve drilling problems with success in many applications with different reservoirs. Improvements in initial flow rates using UBD are being supported by longer term production. UBD techniques and processes are improving through experience and implementation. UBD is becoming a more economical means to optimize reservoir management than conventional overbalanced operations. UBD operations are proving to be safer than conventional overbalanced drilling.