Integrated characterization of lamination development probability and interference index in deep shale based on logging-derived rock mechanical parameters

Deep shale reservoirs commonly contain abundant laminations that may hinder vertical hydraulic fracture propagation, whereas their microscale heterogeneity makes engineering-scale characterization difficult. To address this limitation, this study proposes an engineering-oriented characterization framework that combines lamination development probability with a lamination interference Index derived from logging-based geomechanical parameters and further transforms statistical predictions into engineering-scale descriptors through a risk-partitioned post-processing strategy. The framework was evaluated using a multi-well dataset from the Cambrian Qiongzhusi Formation in the Sichuan Basin. Results show that lamination development probability exhibits broad transition intervals rather than a simple binary distribution, while lamination density and thickness both follow pronounced right-skewed, long-tailed distributions, indicating that a limited number of strongly laminated intervals may dominate vertical fracture interference. The proposed framework achieved an overall discriminant consistency of 71.9% and an average lamination interference index prediction error of 27.9%, demonstrating stable cross-well prediction capability. Statistical response analysis further indicates relatively stable relationships between laminated heterogeneity and multiple rock mechanical parameters. The proposed framework establishes a quantitative linkage between microscale lamination characterization and engineering-scale hydraulic fracturing analysis, providing a practical basis for laminated heterogeneity evaluation, target interval selection, and hydraulic fracturing optimization.