In recent years, major breakthroughs have been achieved in oil and gas exploration within China’s complex thrust–fault zones in the western region, confirming their significant potential. The northern piedmont zone of the Turpan–Hami Basin, a classic thrust–fold belt formed by the Bogda Orogenic belt’s overthrusting, has seen the discovery of several Jurassic–Cretaceous hydrocarbon fields, yet exploration at its thrust-front margins remains relatively underdeveloped. This study focuses on the central piedmont segment at Qialekan and Kekeya, integrating 3D seismic data with fault-related folding theory and balanced cross-section restoration to systematically analyze the area’s tectonic evolution. We specifically examine the formation and modification of wedge structures and assess their petroleum geological significance. Our results indicate that the wedge bodies formed in the Late Jurassic, along with their subsequent basinward insertion, critically controlled the present-day structural framework. In the Qialekan area, wedge formation coincided with the main hydrocarbon expulsion phase of underlying Permian source rocks. Type I faults acted as effective migration pathways, while later tectonic reworking was limited, favoring for hydrocarbon preservation. In contrast, in the Kekeya area, wedge structures underwent intense modification by Type II faults, which pierced the wedge and facilitated vertical hydrocarbon migration, creating a mixed-source accumulation pattern. The findings of this study provide new theoretical insights and practical guidance for future exploration in the northern piedmont zone and also offer a valuable reference for hydrocarbon exploration in structurally similar foreland basins.

The Moliqing Fault Depression, located in the southwestern part of the Yitong Basin, is a Cenozoic strike–slip pull-apart basin controlled by the northern segment of the Tan-Lu Fault Zone. Based on measured formation temperature data from 41 wells and rock thermophysical property data from 41 wells in the study area, terrestrial heat flow values were calculated using a one-dimensional steady-state heat conduction model. On this basis, temperature distribution maps at different depths, a terrestrial heat flow contour map, a formation temperature distribution map of the Shuangyang Formation, and well-to-well geothermal profiles were systematically constructed. The principal factors controlling the geothermal field were further investigated in terms of basement relief, basement lithology, and the spatial distribution of volcanic vents. The results indicate that the geothermal field in the study area exhibits pronounced lateral heterogeneity. Subsurface temperatures range from 39 to 66 °C at a depth of 1000 m, from 65 to 133 °C at 2000 m, and from 91 to 182 °C at 3000 m. The geothermal gradient ranges from 3.0 to 4.9 °C/100 m, with an average of approximately 3.6 °C/100 m. Terrestrial heat flow values range from 58 to 122 mW/m², averaging approximately 84 mW/m². Measurements of rock thermophysical properties show that thermal conductivity ranges from 1.9 to 2.7 W/(m·K), with an average of 2.3 W/(m·K). Radiogenic heat production ranges from 0.985 to 1.3 μW/m³, averaging 1.1 μW/m³. Well-to-well geothermal profiles indicate that basement relief exerts a strong control on the distribution of isotherms. The relatively high radiogenic heat production of the basement granites provides an important internal heat source for the geothermal field. Geothermal gradients increase markedly near volcanic vents, reflecting the perturbing effects of deep-seated thermal activity. These findings provide a scientific basis for hydrocarbon exploration and geothermal resource assessment in the Moliqing Fault Depression.