Stop Criterion for GIN

The GIN model for rock fractures grouting is widely used in practice. The element shared by the practitioners is the GIN envelope. However, different methods are adopted for approaching the GIN envelope during the injection process of a cement mix. Some practitioners stop immediately when reaching the envelope and others follow it for a while. There is no general rule for when and where on the envelope grouting should be stopped. A parameterization of the penetrability on the envelope is provided in this paper. For the parameterization, the grout rheology, the fracture's thickness, the borehole radius and the target are taken into consideration. This allows to define a penetrability limit beyond which the grout process may be stopped. The penetrability is then extended to the case many fractures are injected simultaneously. Numerical simulations are used for graphical illustrations.