Volumetric Rock Damage

Tadeusz Patzek

Introduction: Rock damage is the process of breakage of grain bonds and the initiation and growth of discontinuous microcracks that may coalesce into a fracture.

There are a great number of damage models, plasticity models and methods for modeling rock fractures. The available models of fracture growth do not account for microstructural effects in damage accumulation. We are looking at fracture and change of rock properties from microstructural level and using methods of homogenization of heterogeneous materials, we go from local damage model to non-local damage.

We also investigate the effect of microstructural length scale of rock in the pattern of damage.  This will let us see how fracture grows in reservoir rock as a function of stress state, current damage, temperature, chemical effects and microstructural properties of rock.

Objective: The main objective of this work is the enhancement of hydrocarbon production from tight formations with zero to very low production rates by changing the rock flow properties as the hydrocarbon is produced. Generation of fractures changes the permeability distribution in the rock. In order to calculate the flow rate accurately we need to solve the damage diffusion equation that updates the rock permeability with the progress of damage in time and space.

For more info, please see the Volumetric Rock Damage page.