This article discusses two managed-pressure drilling (MPD) techniques used to overcome differing subsurface challenges. Both techniques relied upon minimizing changes in the bottomhole pressure (BHP) by eliminating or mitigating changes in frictional pressure.
Coiled tubing MPD
The reservoir consisted of a large, highly permeable, homogenous sand section with
Figure 1. How the BHP was maintained by manipulating the surface pressure. When the well was static, backpressure was applied to the annulus to maintain the necessary BHP at 1,000 psi over the hydrostatic pressure provided by the base mud weight....