This study investigates the significant increase in sand production during water injection into unconsolidated sandstone formations. While sand-production rates are primarily governed by changes in rock strength, this research focuses on quantifying the role of capillary pressure (Pc) in modulating capillary strength. By integrating experimental and mathematical modeling approaches, the work aims to advance the understanding of sand-detachment dynamics and formation instability under varying saturation conditions.
Materials and Methods
Sands with particle sizes of 500–600, 300–425, 212–300, 150–212, 63–150, and 63 µm were chosen for this study to represent loose, unconsolidated sand formations. These sands were obtained from a crusher core sample, and the particles were sieved to confirm that all matched the target particle-size distribution (Fig. 1 above).
A mathematical model was used to determine capillary strength by integrating experimental Pc data with mathematical equations.
