An approach to annular pressure control by managed pressure drilling

Narrow operation window is quite common in conventional drilling while encountering pressure depletion or complex formation,leading to downhole problems such as leaking,sticking,blowout,and hole collapse,etc.Managed pressure drilling(MPD) can mitigate or even avert these drilling problems by manipulating annular pressure through controlling the flow rate and regime of annulus circulating media and the pressure applied at wellhead in conjunction with model calculation of annular pressure drop.This technology can reduce non-production time,enhance drilling efficiency,and reduce operation cost.