Numerical Modelling of Radial Crack Propagation in Cement Sheath During Hydraulic Fracturing

Abstract

Abstract The cement sheath are damaged around the hole after perforation, and the micro-cracks in the cement sheath will cause fluid channeling during hydraulic fracturing. Focused on this problem, a numerical model was set up to calculate the crack propagation length in cement sheath during hydraulic fracturing by using the Cohesive Zone Method (CZM). Then the influence of different parameters on the unsealing length of cement sheath during hydraulic fracturing was analyzed. The results show that higher casing pressure can help to reduce the unsealing length of cement sheath. It is significant to perforate with lower density and phase to ensure the sealing integrity of the cement sheath. This research can evaluate the sealing performance of the cement sheath during hydraulic fracturing and give some guiding for the design of fracturing schemes.