Role of mechanical stratigraphy on fracture development in carbonate reservoirs: Insights from outcropping shallow water carbonates in the Umbria–Marche Apennines, Italy

摘要: Abstract Studies on mechanical stratigraphy show that a link exists among facies, sedimentary cycles, diagenesis and fracturing. Understanding this is fundamental for characterising fluid flow in natural reservoirs, especially carbonate ones. This work investigates the field of evidence through case study Umbria–Marche Apennines: Lower Jurassic shallow water carbonates Calcare Massiccio unit, potential reservoir. A multidisciplinary approach used, involving stratigraphy, sedimentology structural geology. The studied succession crops out at core an ENE-verging anticline, located Campolarzo, within Apennines. here consists high-frequency, metre-scale, shallowing upward, peritidal cycles. Three different cycles (thickness ranging from 0.3 to 3 m) have been recognised: type (incomplete asymmetric cycle), B (complete cycle with sheet cracks) C tepees). Sedimentary textures vary according depositional environment. subtidal facies almost entirely mud-supported, exception cycle, which locally can be grain-supported. intertidal mud- grain-supported commonly laminated. supratidal may either absent (type A) or represented by vadose pisoid caliches, cracks B) tepees C). overprinting diagenetic (early diagenesis) particularly evident intervals (tepee structures) inter-supratidal (sheet cracks). fracture pattern mainly systematic joints organized two prominent mutually perpendicular sets (orthogonal joints) subordinate non-perpendicular (diagonal joints). orthogonal are interpreted as tensile developed sub-parallel (longitudinal sub-perpendicular (cross NNW–SSE axial trend host anticline. diagonal shear joints. In area, density strongly controlled heterogeneities rock properties between turn determined and, dominantly, combination e.g., petrofacies. control played petrofacies distribution across stratigraphic justify strong variations (up ca. 80% more) same well terminations, independently tectonic causes. decrease going tepee evident. Minimum values observed structures; fractures often terminate against tepee. lowest characterises where early processes more pronounced (i.e., tepee, affected dissolution cavities filled cements). No obvious correlation thickness layer.