EPI paper accepted for the ARMA 51st US Rock Mechanics / Geomechanics Symposium
April 26, 2017
"Hydraulic Fracture Propagation in Steps Considering Different Fracture Fluids", by Sidney Green (1), Joseph Walsh (2), John McLennan(3), Bryan Forbes(3).
(1 Enhanced Production, Inc. & University of Utah, 2 Retired MIT, 3 University of Utah).
ABSTRACT: Hydraulic fracture propagation under high compressive stresses in rock is considered. An ideal case of a Griffith crack propagating in an ideal material has been calculated by Dr. Joseph Walsh. This ideal case is used to estimate stepwise or continuous fracture propagation for different fracture fluids for a rock with stiffness and strength simulating a shale at a depth of about 6000 feet. More compressible fluids such as CO2 and nitrogen foam show larger stepwise propagation with steps of possibly tens of feet. Indeed rocks are not ‘ideal’ materials, nor are insitu stress magnitudes uniform and continuous. Nevertheless, the calculations here present interesting perceptions of the role of the compressibility of fracture fluids on hydraulic fracture propagation.