Seismic reservoir prediction and application of beach-bar sands in the Baikainuoer Formation of the Triassic System in the Mahu Sag, Junggar Basin

The beach-bar sand body deposits of the Baijiantan Formation of the Triassic System are widely developed in the Mahu Sag. The beach-bar sand body reservoirs in the second member of the Baijiantan Formation（Bai 2 Member） in the study area are characterized by rapid lateral changes, thin single-layer thickness of the oil-producing sandstone, and tiny differences in elastic parameters between the reservoir and non-reservoir. As a result, it is difficult to identify thin sandstones using conventional seismic prediction methods. This paper combines well data with seismic data and conducts in-depth paleogeomorphic analysis. Based on a thorough understanding of the geological conditions, multiple seismic attributes are comprehensively applied to depict the distribution characteristics of lithofacies. To address the challenge that traditional impedance curves cannot effectively identify fine sandstones, the pseudo-acoustic impedance seismic inversion technique is used to accurately identify the oil-producing fine sandstones. Thus, a set of seismic identification methods suitable for the beach-bar sands lithology in the study area has been established, providing key technical support for the subsequent evaluation and development work in the study area and strongly promoting the relevant exploration and development process.