Venezuela Orinoco heavy oil belt eastern M block is a large overseas unconventional extra-heavy oil field. The field is currently in the foam oil cold production stage, with the main formation consisting of braided river deposition containing a thick oil layer. The distribution pattern of interlayer is a critical factor influencing the layout of horizontal wells and the productivity of individual wells. This study aims to explore the impact of interlayer distribution on the cold development effect of overseas extra-heavy oil reservoirs and propose countermeasures to technical challenges. By establishing identification criteria for muddy interlayers in the research area, analyzing the distribution law of interlayer thickness, and utilizing numerical simulation methods, the study examines the influence of interlayer distribution in three main layer sets on development effectiveness. The research findings highlight the significance of interlayer distribution in adjusting horizontal well layouts and development plans. These results are of significant theoretical and practical importance in guiding the cold development of overseas extra-heavy oil reservoirs, providing valuable insights and guidance for technical applications in this field.