Impact of Stress Shadow on Fracture Geometry and Production Performance in Multi-stage Hydraulic Fracturing, Unconventional Shale Gas Reservoir

Abstract

The performance of multi-stage hydraulic fracturing in unconventional shale gas reservoirs is strongly influenced by fracture interactions, particularly the stress shadow effect, in which fracture opening redistributes surrounding stress and alters the propagation of subsequent fractures. This mechanism directly affects fracture geometry and reservoir stimulation efficiency. However, many fracturing designs assume uniform stress conditions and do not fully account for stress redistribution between adjacent fractures, potentially leading to inaccurate predictions of fracture growth and production performance, especially at close spacing. This study evaluates the impact of stress shadow on fracture geometry and gas production using an integrated hydraulic fracturing and reservoir simulation workflow across fracture spacing scenarios from 600 ft to 138 ft. Results show that fracture interaction intensifies as spacing decreases. At 600 ft spacing, fracture width and half-length reductions remain below 2%, indicating limited interaction. At 138 ft spacing, fracture width decreases by an average of 15% and half-length by 23%, with maximum reductions exceeding 46%. Initial gas rate declines from 1489,59 to 1480,39 Mscf/day (0.62%) at 600 ft spacing and from 6234,28 to 4738.78 Mscf/day (31.56%) at 138 ft spacing. Cumulative production also decreases by 5.13% and 29.20%, respectively. These findings highlight the importance of incorporating geomechanical interaction into fracturing design and production forecasting.