Numerical investigation on the effect of depletion-induced stress reorientation on infill well hydraulic fracture propagation

Abstract

Depletion-induced stress change causes the redistribution of stress field in reservoirs, which can lead to the reorientation of principal stresses. Stress reorientation has a direct impact on fracture propagation of infill wells. To understand the effect of stress reorientation on the propagation of infill well's fractures, an integrated simulation workflow that combines the reservoir flow calculation and the infill well hydraulic fracturing modeling is adopted. The reservoir simulation is computed to examine the relationship between the extent of stress reversal region and reservoir properties. Then, the hydraulic fracturing model considering the altered stress field for production is built to characterize the stress evolution of secondary fracturing. Numerical simulations show that stress reorientation may occur due to the decreasing of the horizontal stresses in an elliptical region around the parent well. Also, the initial stress difference is the driving factor for stress reorientation. However, the bottom hole pressure, permeability and other properties connected with fluid flow control timing of the stress reorientation. The decrease of the horizontal stresses around the parent well lead to asymmetrical propagation of a hydraulic fracture of the infill well. The study provides insights on understanding the influence of stress reorientation to the infill well fracturing treatment and interference between parent and infill wells.