CHARACTERIZING ROCK FRACABILITY UPON FRACTURE MECHANICS

ARIEL CHÁVEZ; JOSÉ LUIS OTEGUI; MARTÍN SANCHEZ; BIANCHI GUSTAVO LUIS

Congreso; SOUTH AMERICAN CONGRESS ON ROCKS MECHANICS. ABS; 2015

ABS

Rock fracability characterization is a key issue for stimulation of unconventional reservoirs. This property not only controls hydraulic fracture initiation and propagation pressure, but also affects the Stimulated Reservoir Volume (SRV) which in turn controls well productivity. Several parameters such as brittleness, plasticity and toughness, among others, are frequently referred in the literature to describe rock fracability. This paper discusses the validity of these parameters and emphasizes the validity of the linear elastic fracture mechanics approach based on the critical stress intensity factor (KI) to characterize rock fracability. This article presents results of experimental studies using synthetic and real Vaca Muerta shale Formation samples. Fracture Toughness (KIC) was determined using notched Brazilian discs and semicircular three point bending specimens. The influence of applied load rate, material composition and exposure conditions (air vs. immersed in different fracturing fluids) upon fracability is discussed in terms of KIC and stress Corrosion Cracking Intensity Factor (KSCC) measurements conducted on rock samples.