Development Characteristics and Favorable Area Prediction of Strike-Slip Fault-Controlled Ordovician Fault-Karst Reservoirs in the Yuman Area

This study aims to elucidate the developmental characteristics of strike-slip fault-controlled Ordovician fault-karst reservoirs (FKRs) in the Yuman area of the Tarim Basin. By integrating regional tectonic settings with high-resolution 3D seismic data, we implemented a comprehensive 3D seismic interpretation strategy. Concurrently, a statistical evaluation of 22 strike-slip fault segments was conducted based on their kinematic attributes, connectivity, and seismic “string-of-beads” responses. The results indicate that the Yuman area is dominated by an interlaced network of NE-striking (sinistral transpressional) and NS-striking (dextral transpressional) faults. Three distinct reservoir-controlling patterns were identified among the 22 FKRs: Type I deep-penetrating transpressional (7 segments), Type II deep-penetrating transtensional (4 segments), and Type III weakly penetrating transpressional (11 segments). Based on reservoir scales and structural positioning, seven high-priority exploration targets were successfully delineated. Furthermore, the results reveal that fault structural maturity, vertical penetration, and kinematic regimes are the pivotal factors controlling FKR quality and stratigraphic distribution. Type I patterns exhibit the highest structural maturity and develop cross-stratigraphic, large-volume reservoirs in shallow sections, representing prime targets. Conversely, Type III reservoirs are deeply buried due to constrained fault growth. Ultimately, reservoir evaluation priority ranges from Type I, through Type II, to Type III, with Targets ① to ④ identified as the most promising candidates for localized exploration breakthroughs.