High pressures are often encountered in the Naricual formation, in the Northern Monagas Basin in Venezuela. In an effort to control these high pressures, the Naricual formation is typically drilled in multiple intervals, including the 8½-in. and 6½-in. sections. Typically, the pressure differential encountered between the Naricual formation and the San Juan formation below requires a complex drilling fluid and well design.
FLC 2000, an ultra-low invasion fluid additive for Wellbore Shielding® and stability, was used to drill multiple intervals in a 14-well drilling program at 5 lb/bbl. Logging confirmed high differential pressures, in excess of 7,000 psi in the MUC-166 well (see charts).
In multiple wells during this drilling program, the Naricual formation was drilled in one section (8½-in.), eliminating the 6½-in. section originally planned. FLC 2000 performed at high differential pressure, eliminating the need to drill the additional interval, saving the operator on drilling costs—by eliminating the casing string—and reducing drilling time. Testing by the operator also demonstrated a 93% reduction in formation damage.
For additional information about this drilling campaign, please review our co-authored SPE paper with PDVSA.