This paper describes efficient detection of well-control events, in both underbalanced and overbalanced conditions. This is especially relevant for deepwater operations because the reaction time is significantly less than with surface blowout preventers (BOPs). A methodology is offered to detect the annulus-fluid level in conditions of unknown hydrostatic-column height and fluid density through the use of discrete annular-pressure acquisition along a networked drillstring.
Downhole-Fluid-Level Analysis
Annular-pressure-while-drilling (PWD) data are commonly available through measurement-while-drilling (MWD) services and have the potential for fluid-level detection. But until recently, mud-pulse technology could provide data only during dynamic conditions when the circulation rate exceeded a minimum threshold. Operationally, the pump rate would usually be reduced to below such a threshold in an attempt to reduce the severity of the losses.
