Abstract: The detailed characterization of relatively high porosity and permeability sweet spots in deep low-permeability reservoirs is the most crucial breakthrough for increasing oil and gas reserves and production in the East China Sea. The W Structure in the study area belongs to a complex riverine sedimentary environment system. The reservoirs have a large burial depth, and the depiction of multiple river channel morphologies is difficult, with significant variations in the internal heterogeneity of the sandbodies. Practice has proved that accurately identifying the sweet spots in the river valley area is the key to successfully breaking through the ice. First, by optimizing seismic fidelity and amplitude, the quality of pre-stack trace sets in the middle and deep layers was improved. Then, a high-precision rock physics model of the low-permeability reservoirs in this area was established. Based on a comparative analysis of forward modeling of pre-stack gather and derived attribute of drilled wells, a new attribute Ψ was constructed to carry out the depiction of high-porosity superior sandbodies in river channels. Moreover, based on seismic petrophysics, the Poisson impedance PI and elastic impedance EI(θ) were combined, and the hierarchical and semi-quantitative characterization of permeability reservoirs was achieved progressively. Finally, in the area where the sedimentary paleogeomorphology, river distribution, and sweet spot prediction are highly superimposed, the developmental range of river valley superior reservoirs was delineated. Field drilling demonstrated that the distribution of sweet spots in river valley area in low-permeability reservoirs mapped by this technology has a high degree of confidence, which strongly supports the evaluation of potential targets and well location design and deployment in the study area, and has a good prospect for application and promotion.