Fracture morphology reconstruction and propagation behavior analysis of zipper fracturing in clustered well platforms based on microseismic monitoring

Zipper fracturing is widely used in shale gas development to enhance stimulation efficiency, but it presents challenges in characterizing hydraulic fracture networks due to stress interference among adjacent wells and stages. This study proposed an integrated workflow incorporating microseismic denoising, fracture orientation identification, geometry reconstruction, and stimulation evaluation. The method was applied to four horizontal wells on the H3 platform in the Fuxing area, Sichuan Basin. Results show that inter-well stress interactions alter fracture propagation direction, increasing the dispersion and overlap of microseismic events. Each fracturing stage with 6–9 clusters typically generated 4–7 dominant fractures. Near-wellbore networks exhibit complex and asymmetric geometries, especially in low-pore-pressure zones, which promote longer half-lengths and greater deflection angles, while high-pore-pressure zones produce more chaotic patterns. On average, fractures on the zipper side are 6–32 m longer, and upper-side fractures are 5–33 m higher than their counterparts. To quantify fracture complexity and connectivity, a Fracture Network Complexity Index (FNCI) is introduced based on fracture half-length, deviation angle, and intersection density. Fractal dimension, topological connectivity, and intersection length are also used to evaluate network structure. These quantitative metrics improve understanding of fracture propagation under stress interference and provide guidance for optimizing fracturing design and stimulation performance in unconventional reservoirs. • Integrated method for 3D fracture network reconstruction and stimulation effect evaluation • Connectivity and complexity indicators for hydraulic fracture network assessment • Fracture geometry influenced by inter-well and interstage stress interference