Characterizing the Present-day Stress Field and Fracture Intensity in the Kuqa Depression, Northwestern China

Stress fields govern subsurface conditions and fracture development, which strongly influence hydrocarbon migration and accumulation in tight reservoirs. Yet, their characterization has often overlooked structural complexity and temperature effects. Here we construct a three-dimensional structural model of the Bozi-Dabei area in the Kuqa Depression and employ a thermo-viscoelastic-plastic constitutive model to simulate the stress state of ultra-deep Cretaceous reservoirs beneath a thick gypsum-salt formation. The simulated stresses show close agreement with in-situ measurements from 15 boreholes, achieving a 93.3% consistency rate with errors below 11%. Core observations further reveal a positive correlation between effective tensile stress and fracture density. Guided by this relationship, we delineate 14 zones of high fracture density within the Cretaceous reservoir. Thirteen of these zones are spatially consistent with proven hydrocarbon traps identified through prior exploration. This work establishes a new framework for stress-field characterization by integrating realistic geological architecture, thermal–mechanical coupling, and advanced constitutive modeling, offering a robust approach to reduce exploration risks and enhance drilling success in fractured reservoirs.