While supercritical carbon dioxide (CO2) flooding yields microscopic displacement efficiencies exceeding 90%through oil swelling, viscosity reduction, and interfacial tension (IFT) minimization, field-scale recovery in heterogeneous carbonates is severely compromised by macroscopic flow instabilities. In fractured and low-permeability carbonate systems, unfavorable end-point mobility ratios (M^∘>10), gravity segregation (N_g>1), and high fracture-to-matrix permeability contrasts (k_f/k_m>10^3) induce severe viscous fingering and premature gas breakthrough, frequently restricting volumetric sweep efficiency (E_V) to under 35%. Following PRISMA systematic review guidelines across 185 peer-reviewed studies and historical field datasets (1972–2024), this review delivers an integrated, multi-scale critical analysis contrasting microscopic phase behavior with field-scale conformance limitations. We establish a quantitative, multi-criteria performance benchmarking of the three primary mobility-control strategies water-alternating-gas (WAG), CO2 foam, and direct CO2 thickeners evaluated across mobility reduction factor (MRF), deep-reservoir propagation, and injectivity penalties. Key findings reveal that while WAG achieves modest mobility control (MRF≈2"-" 5), it remains vulnerable to severe gravitational override and fracture bypassing. Conversely, nanoparticle-stabilized foams exhibit superior conformance (MRF>50) in discrete fracture networks, maintaining thermodynamic and lamellae stability under extreme conditions ("TDS">150,000" ppm" , T>90^∘ "C" ) where conventional surfactants precipitate. Direct thickeners, although improving viscosity up to 40-fold, face commercial deployment barriers due to severe near-wellbore injectivity losses and prohibitive chemical costs (10"-" 25× WAG). Finally, translated to complex Middle Eastern carbonates (Asmari and Sarvak formations), we define geomechanically constrained operational envelopes, demonstrating that injection overpressures must be strictly throttled (ΔP<6"-" 8" MPa" ) to avert brittle caprock slip while maintaining bottom-hole pressure below the asphaltene onset envelope (2.5"-" 8.5" wt" % asphaltene). This review provides an actionable operational roadmap for transitioning from empirical injection schemes to dynamic conformance engineering in fractured carbonate reservoirs.