SPE Annual Technical Conference and Exhibition · 1995 · 26 citations · 7 references
EngineeringEarth SciencesPetroleum EngineeringHydraulic FracturingReservoir EngineeringSubsurface Fluid FlowFluid Loss ControlFluid-flow In Porous MediaFracture MechanicsNear-wellbore EffectsPermeability AnalysisRock PermeabilityFluid LeakoffFluid Leakoff EffectsFormation DamageHydraulic Fracturing FluidsLeakoff AnalysisLeakoff TestingNear-wellbore DamageStatic Fluid Loss
High‑permeability formation stimulation relies on short fractures to avoid near‑wellbore damage, yet the leakoff behavior of fluids in such rocks remains poorly understood. The study investigates fluid‑loss behavior and formation damage in high‑permeability cores through static‑fluid‑loss and reverse‑flow experiments. Experiments used 12‑inch cores (3–1,000 md) in a Hassler cell with six pressure taps at 2‑inch intervals, testing borate‑crosslinked‑guar, linear‑guar, linear‑HEC, and viscoelastic‑surfactant solutions. Results show that differential pressure, gel concentration, permeability, and temperature affect spurt and leakoff coefficients, with internal cake dominating spurt and total leakoff for crosslinked fluids; linear HEC behaves shear‑thinning, and a nonlinear algebraic equation extending the Williams expression for power‑law fluids was derived for simulators.
ABSTRACT A recent trend in stimulating high-permeability formations is the development of techniques (such as frac-pack) to create short fractures which bypass formation damage in the near-wellbore region. Analysis and refinement of these techniques are hampered by a lack of knowledge of the leakoff behavior of candidate fluids in high-permeability rocks. In this paper, we present results from static-fluid-loss and formation-damage (reverse-flow) experiments using 12-inch-long cores in the permeability range of 3 to 1,000 md. A Hassler cell, with 6 pressure taps placed at 2-inch intervals, was used. The test fluids included borate-crosslinked-guar, linear-guar, linear-HEC, and viscoelastic-surfactant solutions. The effects of differential pressure, gel concentration, permeability, and temperature on spurt and leakoff coefficients were investigated, and correlations were given. In the absence of fluid-loss-control additives, the internal cake is the controlling factor for spurt and total leakoff for crosslinked fluids. Linear HEC behaves as a shear-thinning fluid during flow through porous media. A nonlinear, algebraic equation generalizing the well-known Williams expression for Cvo to power-law fluids was derived as an approximate method of incorporating the leakoff behavior of power-law fluids into current fracturing simulators.
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Aspects of flow of power‐law fluids in porous media
C. Shah, Y. C. Yortsos · AIChE Journal · 1995 · 74 citations