An experimental study on casing perforation erosion during sand fracturing

A sand-fracturing casing perforation erosion experimental device was designed to explore the casing perforation erosion behavior under different working conditions in the study. The influences of different factors on the casing perforation erosion mechanism were investigated based on macro-scale observations and SEM images. The serious perforation erosion occurred in the direction of the flow inlet and led to asymmetric funnel. The influences of various parameters on the perforation expansion rate were ranked according to the following order: sand-passing quantity of perforation > pump displacement > sand concentration > proppant size. Under a low sand concentration, the erosion effect of proppant particles on casing perforations was mainly caused by cutting and ploughing. Under a high sand concentration, shallow craters and brittle cracking were increased. The findings can guide the control of casing perforation erosion and improve the understanding of the perforation target erosion wear mechanism of the solid-liquid two-phase flow. [Display omitted] •A sand-fracturing casing perforation erosion experimental device was designed.•Influences on perforation quality loss and expanding rate were analyzed.•Influences on the mechanism of perforation erosion were analyzed.•Macro-scale observations and SEM images were used to study the mechanisms.