Plasticity effects in hydraulic fracturing

Journal Article · Mon Sep 01 04:00:00 EDT 1986 · J. Pet. Technol.; (United States)

DOI:https://doi.org/10.2118/11068-PA· OSTI ID:5213728

Medlin, W L; Masse, L

The importance of reservoir rock plasticity in fracturing operations has been investigated by laboratory experiments and field results. A Lagrangian formulation for crack propagation provided the basis for the laboratory experiments. A simple crack propagation experiment showed that plasticity effects can be observed and that the importance of plasticity depends on the relative magnitudes of surface energy and energy dissipated in plastic deformation of a reservoir rock. The latter can be evaluated by laboratory measurements of a plasticity coefficient, ..cap alpha.., which comes out of the Lagrangian analysis. To measure ..cap alpha.., the authors developed a triaxial system for applying tensile stress to rock cores under confining pressure at strain rates characteristic of fracturing operations. Strain gauges mounted on each core were used with a servo-controlled press to apply strain at a linear rate between 10/sup -4/ and 10/sup -6/ seconds /sup -1/ and to obtain stress/strain data to the point of tensile failure. To distinguish between plasticity and nonlinear elastic phenomena, the authors also obtained strain hysteresis data.

• Research Organization: Mobil Research and Development Corp., Dallas, TX
• OSTI ID: 5213728
• Journal Information: J. Pet. Technol.; (United States), Journal Name: J. Pet. Technol.; (United States) Vol. 38:10; ISSN JPTJA
• Country of Publication: United States
• Language: English

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BENCH-SCALE EXPERIMENTS
COLORADO RIVER BASIN
COMMINUTION
CONTROL EQUIPMENT
CRACK PROPAGATION
DEFORMATION
ELASTICITY
ENERGY
ENERGY LOSSES
ENERGY SOURCES
ENHANCED RECOVERY
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EUROPE
FEDERAL REPUBLIC OF GERMANY
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FOSSIL FUELS
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FREE ENERGY
FUEL GAS
FUELS
FUNCTIONS
GAS FUELS
GASES
HYDRAULIC FRACTURING
LAGRANGIAN FUNCTION
LOSSES
MEASURING INSTRUMENTS
MECHANICAL PROPERTIES
MECHANICS
NATURAL GAS
NATURAL GAS WELLS
NONLINEAR PROBLEMS
OIL WELLS
PETROLEUM
PHYSICAL PROPERTIES
PICEANCE CREEK BASIN
PLASTICITY
PRESSES
RECOVERY
RESERVOIR ROCK
ROCK MECHANICS
SERVOMECHANISMS
STIMULATION
STRAIN GAGES
STRAIN RATE
SURFACE ENERGY
SURFACE PROPERTIES
TENSILE PROPERTIES
THERMODYNAMIC PROPERTIES
WELL STIMULATION
WELLS
WESTERN EUROPE