Development Characteristics and Distribution Patterns of Natural Fractures in the Tight Reservoirs of the Ahe Formation in the Dibei Area of the Tarim Basin

In the context of the evolving global energy landscape, tight gas fields have gained in-creasing significance due to their low-porosity and low-permeability reservoirs, where natural fractures play a critical role in improving permeability and enhancing storage capacity. Foreland basins, such as the Dibei area in the northern Kuqa Depression of the Tarim Basin, are typical hosts for tight gas reservoirs, but the complex fracture development induced by multiple tectonic movements restricts natural gas exploration. This study employs core observation, imaging logging analysis, and thin-section microscopy to characterize the genetic types and development features of natural fractures in the Ahe Formation. Results show that 54% of natural fractures in the Dibei area are structurally originated, predominantly high-angle and open. The highest fracture density (0.351 fractures/m), six times that of other regions, occurs in the upper horst zones. Three fracture patterns are identified, namely fault–fold, fault-related, and monocline types. Fault–fold fractures are most developed due to folding and thrusting, while monocline zones are poorly fractured. Structural fractures are best developed in horst crests with fault–fold patterns. Fracture development is jointly controlled by folds, faults, stress, and lithology, with distinct characteristics across different structural positions and lithological combinations. Clarifying the development characteristics and distribution patterns of natural fractures in the Ahe Formation of the Dibei area facilitates accurate evaluation of high-quality reservoirs, providing crucial geological basis for optimizing hydrocarbon sweet spots and refining accumulation models in the region.