Abstract
Hydraulic simulation is an integral part of any Managed Pressure Drilling (MPD) operation. Engineers rely on hydraulic calculation throughout an MPD project. A very detailed wellbore hydraulic analysis will not only foretell the success of various MPD methods but may also guide the drill engineer in real-time while contenting with difficult hydrodynamcis scenarios. Most MPD operations are conducted in narrow pressure windows formation, which require the pressure in "precise control". However, there are many parameters that play a part in the managing of wellbore pressure during circulation. Bottom hole pressure are impacted by fluid density and rheologic properties, injection rates, temperatures in annular and pipe, casing and drilling string configuration. The effects of these parameters on the bottomhole pressure are different, but interact with one another. A good understanding of the effects of these parameters on bottomhole pressure is essential in the hydraulic simulation.
In the paper, detailed hydraulic analyses of MPD operation in narrow pressure windows are presented. The detailed inform collecting is the first step for hydraulic simulation. According the drilling fluid used in the MPD operation, the rheology models of drilling fluid were compared and determined. The Roberston-Stiff model was employed in this paper. Based on experiments and theoretical analysis, the effects of temperature and pressure on ESD and shear stress of drilling fluid were considered. Some often overlooked parameters such as tool joint parameters, pump feed efficiency etc., were also considered Integrated into account the above factors and other conventional factors such as hole geometry, drilling string configuration, etc., the hydraulic simulations of MPD were conducted. The simulation results were compared with on-site real time PWD data. The hydraulic simulation results are in good agreement with on-site real time PWD data.
