D
rilling in narrow pressure margins has historically posed
significant fluid challenges. Fluctuations in fluid densities,
coupled with formations that are extremely sensitive to
pressure spikes and have strict zonal isolation requirements
have often dictated the use of multiple fluid solutions to drill and
complete narrow margin wells.
Organophilic clay-free invert emulsion fluids are typically
the systems of choice for narrow margin drilling applications.
The low solids content allows for lower equivalent circulating
density (ECD) values, while the enhanced low-shear rheology
profile can provide exceptional drilling performance.
Additionally, organophilic clay-free invert emulsion fluids often
exhibit quickly-forming gels that are easily broken at low shear
rates. The gels help suspend weighting agents during pump
downtime, effectively reducing barite sag. Once the pumps are
turned back on, very little pressure is required to break the gels,
J.J. MILLER & D. NELSON MCMILLAN, HALLIBURTON BAROID,
DISCUSS A NEW DUAL-PURPOSE DRILLING AND COMPLETION FLUID.
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