Sand production is a crucial operational and design concern for wells in unconsolidated reservoirs. Various well completions have been used to minimize sanding, however, it is very challenging to verify their efficiencies from the sand control standpoint. In this research, we numerically studied the sand failure mechanisms for cased hole frac-pack (CHPF), open-hole frac-pack (OHFP), and open-hole gravel pack (OH) completions. The main objective of this study is to provide insight into the effectiveness of well completions in minimizing sand production. We investigate critical factors affecting wellbore integrity problems, such as well completion types, post-yield behavior of the rock, frac-pack width, poro-elasto-plastic effects caused by fluid production, and the impact of compressive failure around frac-packs. Based on the wellbore integrity simulations presented in this work, well completion design and operations can be improved to minimize sand production.