Abstract:

Deep shale gas reserves in southern Sichuan represent a significant opportunity for augmenting China's natural gas reserves and production. One critical factor influencing the permeability and productivity of individual wells in these deep shale gas reservoirs is fault connectivity. Previous research has primarily focused on fault morphology and combination styles, with little systematic quantitative assessment of fault connectivity. This study targets the Wufeng Formation reservoir in the central Luzhou section of the southern Sichuan Basin, initiating a detailed analysis of the fault network structure and connectivity using multiple faults as reference points. Findings indicate that faults in the Wufeng Formation of the central Luzhou area are well-developed, with an average of 1.12 connection points per branch network. These networks potentially form highly permeable channels favorable for shale gas transport. The central and southern parts of the study area exhibit higher fault dispersion, fault length dispersion, and fault density, which contribute to a greater number of connecting nodes and branches. This enhanced connectivity is conducive to the development of high-production wells. The connectivity assessment results from these regions are superior to other studied areas, indicating notable potential for high-yield well development in the Wufeng Formation.

Key words: central Luzhou Block, deep shale gas, connectivity evaluation, topological structure, fault network