Replacing conventional brittleness indices determination with new attributes using true hydrofracturing mechanism

Abstract

Shale resource plays are associated with low permeability; hence, hydraulic fracturing is required for their stimulation and production. Even though considerable nonuniqueness exists in identifying favorable zones for hydraulic fracturing, geophysicists seem to be avid followers of low-Poisson’s ratio and high-Young’s modulus brittleness criteria, proposed a decade ago. We highlight the misinterpretation that one may run into in following such a criterion for any shale play and develop a new attribute that makes use of strain energy density and fracture toughness. Although the former controls fracture initiation, the propagation of fractures is governed by the latter. Because hydraulic fracturing comprises both these properties, it is firmly believed that the new proposed attribute could be used to highlight the favorable intervals for fracturing. Core data, well log curves, along with mud logs have been used to authenticate the proposed attribute. Finally, computation of the new attributes is implemented on the seismic data with encouraging results.