DAPC

Dynamic Annular Pressure Control (DAPC) is a system designed to apply a controlled surface pressure to achieve a predetermined constant bottom-hole pressure, which can maximize drilling speed while minimizing the possibility of sticking. The pump package, which starts and stops automatically will increase the downhole pressure by pumping mud down the annulus. The size and depth of the well will determine the desired injection rate and therefore the size of the pump. Typically, the pump is electric motor driven, and the package is rated for Class 1, Division 2, and Group D locations; it can be outfitted with either a soft-start or variable frequency drives. An optional centrifugal charge pump is available.