Comparison of 2D plane strain and radial hydraulic fracturing propagation in the viscosity-dominated regime with an analytical approach

Document Type : Research paper

Authors

1 Department of Civil Engineering, Faculty of Engineering and Technology, University of Mazandaran, Babolsar, Iran

2 Department of Civil and Environmental Engineering, Tarbiat Modares University, Tehran, Iran

10.22034/hydro.2024.59590.1313

Abstract

Several factors, such as fluid viscosity, density, and medium toughness, can influence the hydraulic fracture growth process. It is important to note that these parameters do not affect the growth process equally, and one or more of the parameters may have a more significant impact than the others. As a result, it can lead to one or more regimes. The regimes are named based on the process of energy dissipation, the most important of which are: first: toughness regime, where the most energy of fluid injection is dissipated due to rock failure, second: viscous regime, where the greatest input power loss is caused by the movement of viscous fluid in the crack. The research investigates crack growth in a brittle (elastic) rock medium employing linear elastic fracture mechanics (LEFM). The fluid is assumed to be incompressible and Newtonian. The study examines the growth of hydraulic cracks with various geometric shapes such as KGD and radial cracks. The results show that the semi-analytical method for solving the coupled governing equations of hydraulic fracturing has sufficient accuracy and high convergence speed. During the early stages of the hydraulic fracturing process, the KGD crack grows at a faster rate than the penny-shaped crack. However, at later stages, the growth of the penny-shaped crack greatly exceeds that of the KGD crack. Furthermore, the rate of KGD crack opening is higher than that of the penny-shaped crack. As a result, there is a significant decrease in the growth rate of the penny-shaped crack in the viscosity regime relative to KGD.

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