Hydraulic fracture propagation in highly permeable formations, with applications to tip screenout

This paper describes hydraulic fracture propagation in a permeable medium by means of the so-called tip screenout technique. A simple self-consistent mechanical model that allows us to clarify mechanics of proppant bridging at the fracture tip and explain some of the discrepancies between simulation and treatment data is presented. Slurry flow in the fracture is calculated using a single-phase approach with an effective viscosity, taking into account filtrate leakoff across the fracture faces, and kinetics of filter cake growth. The Khristianovich–Zheltov–Geertsma–De Klerk (KGD) fracture model is formulated in a moving coordinate system with a fixed number of nodes, and is solved iteratively using a mixed explicit–implicit finite difference technique. Results of numerical experiments and model verification are presented.

► Hydraulic fracture propagation by means of the tip screenout technique is modeled. ► The leakoff model used is more general compared to the traditional one. ► Observed net pressure slope can be lower than predicted due to plug permeability. ► Impermeable plug assumption can lead to error (5–25%) in the fracture volume created. ► The model developed allows us to investigate the dynamics of fracture propagation.