Detection of Kicks With Networked Drillstring and Along-String Pressure Evaluation

Fig. 1—MWT devices that (a) provide connection to the networked drillstring in static conditions and during connections and (b) provide connection in dynamic conditions while hoisting the string.

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. Furthermore, PWD data measure pressure at only a single location, so pressure gradients across particular sections are unknown for detecting the origin of gains or location of losses. Another practical concern is that an effective fluid-­density estimate is required to compute ­hydrostatic-column height if only one pressure measurement is available, and density is likely unknown because the hole will be filled with seawater. Finally, negative-­pulser technology functions in a very limited manner during severe losses, leaving wellsite personnel deprived of downhole data and short of meaningful surface data.

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 163417, “Detect Kicks Prompted by Losses and Direct-Measurement Well-Control Method Through Networked Drillstring With Along-String Pressure Evaluation,” by Daan Veeningen, SPE, NOV IntelliServ, prepared for the 2013 SPE/IADC Drilling Conference and Exhibition, Amsterdam, 5–7 March.
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Detection of Kicks With Networked Drillstring and Along-String Pressure Evaluation

01 June 2015

Volume: 67 | Issue: 6


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