Intra-layer heterogeneity of sandstone with different origins in deep-water environment and its causes

•The paper uses BP neural network for comprehensive evaluation of reservoir intra-layer heterogeneity.•The intra-layer heterogeneity is studied from the perspective of different origin of the deep-water sedimentary sandstone.•Sedimentation processes, granular rhythm and bedding structure are the main influencing factors of intra-layer heterogeneity.