Integrated high density seismic imaging and structural characterization of the Yahu deep brine system, Qaidam Basin

Deep brine systems in continental lacustrine basins are important strategic mineral resources, but their structural and depositional controls remain difficult to resolve in areas with strong faulting and complex fold geometry. In the Yahu deep brine prospecting area of the Qaidam Basin, we acquired a high density 2-D seismic dataset and integrated it with multi data to improve the imaging of deep brine-related structures. Forward modelling was used to optimize spatial sampling, spread length, and fold, and the resulting acquisition geometry significantly enhanced the signal-to-noise ratio and reflector continuity of the final seismic sections. Horizon calibration identified four major seismic markers, T 1 , T 2 ′, T 2 , and T 3 , corresponding respectively to the bases of the Shizigou, Upper Youshashan, Lower Youshashan, and Upper Ganchaigou formations. The processed data reveal that shallow reflectors are stronger and more discontinuous, whereas deeper reflectors are weaker but remain traceable after careful processing and horizon tying. Velocity analysis produced a layered velocity framework consistent with the depth dependent compaction trend observed in the wells, and the final migrated sections show a structurally complex shallow domain overlying a more coherent deep anticline. We indicate that the Yahu area is a vertically inherited faulted anticline system controlled by a shallow detachment fault, with shallow fault segmentation and secondary normal faults superimposed on a deeper, more complete closure. This study lies in the integration of forward model guided high density 2-D seismic acquisition, well tied horizon calibration, and structural interpretation to resolve the vertically inherited faulted anticline architecture of the Yahu deep brine system. Compared with previous geochemical, this workflow provides a higher resolution structural framework for evaluating deep brine preservation.