Energy Release Rate in hydraulic fracture: can we neglect an impact of the hydraulically induced shear stress?

TL;DR

This paper introduces a new hydraulic fracture model that includes shear stress effects, providing more accurate physics representation and computational advantages over classic models.

Contribution

A novel HF formulation incorporating hydraulically induced shear stress is developed, improving physical accuracy and numerical efficiency.

Findings

The revised model aligns with linear elastic fracture mechanics asymptotics.

Numerical simulations show computational benefits of the new formulation.

Asymptotic solutions are provided for different toughness regimes.

Abstract

A novel hydraulic fracture (HF) formulation is introduced which accounts for the hydraulically induced shear stress at the crack faces. It utilizes a general form of the elasticity operator alongside a revised fracture propagation condition based on the critical value of the energy release rate. It is shown that the revised formulation describes the underlying physics of HF in a more accurate way and is in agreement with the asymptotic behaviour of the linear elastic fracture mechanics. A number of numerical simulations by means of the universal HF algorithm previously developed in Wrobel & Mishuris (2015) are performed in order to: i) compare the modified HF formulation with its classic counterpart and ii) investigate the peculiarities of the former. Computational advantages of the revised HF model are demonstrated. Asymptotic estimations of the main solution elements are provided for the cases of small and large toughness. The modified formulation opens new ways to analyse the physical phenomenon of HF and also improves the reliability and efficiency of its numerical simulations.