Influence of Wear on Burst Resistance and Sealing Effectiveness of Casing Connection

The degradation of casing due to wear is a crucial factor contributing to the problems of wellbore integrity. Although the impact of wear on the burst resistance of the casing body has been extensively studied, fewer investigations have focused on the burst resistance and sealing effectiveness of worn casing connections. This is due to the complexity of their mechanical properties. The objective of this research is to evaluate how wear affects both the burst resistance and sealing effectiveness of casing connections. Three-dimensional finite element models of worn casing connections were developed to explore the relationship between burst resistance and wear depth. The findings indicate that as wear depth increases, the burst resistance of the casing connection decreases. Additionally, the effect of wear on the contact stress at the sealing interface was analyzed. The results suggest that wear exacerbates the uneven distribution of contact stress on the sealing interface. A greater wear depth leads to a significant reduction in the sealing effectiveness of the casing connection. An evaluation model for the burst resistance of worn casing connections has been developed, incorporating Murtagian’s test results and seal contact energy theory. This model accounts for sealing integrity and provides a more practical framework for assessing the burst resistance of casing connections.