Numerical calculation of penny-shaped hydraulic fracturing model based on FrackOptima
It is difficult to maintain accuracy and stability of numerical simulation of penny-shaped hydraulic fracture when the low viscosity of fracturing fluid makes the values of dimensionless toughness more than 3.Thus,we studied the penny-shaped hydraulic fracturing model with a fully-three-dimensional simulator FrackOptima,mainly focusing on the values of dimensionless toughness above 3.We first analyzed the penny-shaped model with its modeling theory and the four parametric conditions for semi-analytical solutions.Then,we conducted numerical examples to simulate fracture propagation with FrackOptima under the four conditions.We compared the numerical results of FrackOptima with those of the semi-analytical solutions.The results indicate the absolute values of errors are less than 10%.The simulation still gives accurate and stable results with the values of dimensionless toughness at 3-19 due to extremely low viscosity,thus providing theoretical basis for further optimizing the practical fracturing treatment,particularly the low viscosity slick water fracturing with the numerical simulation.