The mechanism analysis for hemiwicking on spontaneous imbibition in tight sandstone based on intermingled fractal model

Tight sandstone has relatively low permeability, with various mineral pores. Hemiwicking on micro-nano pore walls is special, which will finally influence the imbibition behavior. Commonly, in traditional strongly waterwet-matrix-based imbibition model ignored the important influence of hemiwicking on imbibition process. In this work, intermingled fractal method is introduced to represent the tight sandstone based on the experiment data. Then a novel imbibition model is built considering hemiwicking, main meniscus imbibition and dynamic wetting in matrix. The model is verified by experiment data. Finally, the mechanisms of hemiwicking is discussed. It shows that hemiwicking is very important when investigating the special imbibition behavior in tight sandstone. This work provides a novel revised imbibition model for gas-liquid spontaneous imbibition, which may be helpful for imbibition analysis within shut-in period after hydraulic fracturing in tight formation in field.

Automated summary

In this study, an intermingled fractal method was used to represent tight sandstone, and a new imbibition model considering factors such as hemiwicking, main meniscus imbibition, and dynamic wetting in the matrix was established and validated using experimental data. The results showed that hemiwicking is crucial when investigating imbibition behavior in tight sandstone.