LAUSR

Abstract Horizontal drilling and hydraulic fracturing enabled the extraction of hydrocarbon from tight formations in countries such as the United States, China, and Argentina. Some factors such as stress anisotropy, formation temperature and quantity of natural fractures are reservoir specific and should be considered in the completion design; otherwise, high rates and pressures applied during hydraulic fracturing in a long horizontal section could induce wellbore integrity issues. Based on field parameters, we studied how the integrity of the cement and casing is affected during these operations using finite element analysis (FEA) to study the stress concentration in casing and cement. The yield criterion of equivalent von Mises stress was applied in order to verify if the stresses were exceeding the casing yield strength and the cement compressive strength. Simulation results revealed that a poor centralization that contributes to the formation of drilling fluid voids in the cement will induce casing failure during hydraulic fracturing operations. The equivalent maximum stress can increase from three to four times in casing and cement from a concentric case to an eccentric case in a cement sheath with voids.