Continuum damage mechanics model of hydraulic fracturing

This work introduces a relatively new branch of fracture mechanics, continuum damage mechanics, as an extension to currently used hydraulic fracture propagation models. A modified version of the Perkins-Kern-Nordgren model is constructed. The new approach attempts to resolve inconsistencies that are evident in current model applications. The main idea is to replace the fluid-flow-constrained tip propagation boundary condition by a new one derived from continuum damage mechanics. It is demonstrated how 'abnormally high treating pressures' can be interpreted using this approach. A combined parameter responsible for fracture propagation retardation is shown to be easily identifiable. The model results are given in a form suitable for computer representation to allow easy applications in treating pressure interpretation and fracture treatment design.

Overview