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  • Managed pressure drilling-What is it anyway?

    K. Malloy

    In the conventional drilling circulation flow path, drilling fluid exits the top of the wellbore open to the atmosphere via a bell nipple, then through a flowline to mud-gas separation and solids control equipment, an open vessel approach. Drilling in an open vessel presents difficulties during operations that frustrate every drilling engineer. Annular pressure management is primarily controlled by mud density and mud pump flowrates. In the static condition, bottomhole pressure (PBH) is a function of the hydrostatic column’s pressure (PHyd). In the dynamic condition, when the mud pumps are circulating the hole, PBH is a function of PHyd and annular friction pressure (PAF), Fig. 1. In an open-vessel environment, drilling operations are often subjected to kick-stuck-kick-stuck scenarios that significantly contribute to Non-Productive Time (NPT), an add-on expense for many drilling AFEs. In an open vessel, pressures cannot be adequately monitored unless the well is shut-in.

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2013 Fracturing Technology

2013 Fracturing Technology