鄂尔多斯盆地已发现延9油层组油藏大多位于曲流河三角洲平原分流河道砂体之中，其单砂体叠置关系复杂多变，对石油开发影响规律不清。以姬塬油田G162区延9油层组为例，开展了其单砂体垂向和侧向叠置关系及其砂体连通性的深入研究，揭示了其对注水开发的控制作用。结果表明，研究区目的层单砂体垂向叠置关系主要为切叠式，占比64%；其单砂体侧向叠置关系主要为同一河道式和侧切式，占比57%，其中切叠式和同一河道式接触的单砂体连通性好，其余连通性弱或差；在平行物源方向上的分流河道微相内，其单砂体多以切叠式和同一河道式叠置为主，注采对应好，水驱控制效果较好；在垂直物源方向上的分流河道微相内，其单砂体多以叠置式和侧切式接触为主，注采对应较弱，水驱控制效果一般，在垂直物源方向上的分流河道侧翼微相内，其单砂体多以孤立式、侧切式和间湾接触式为主，注采对应弱，水驱效果较差。可见，研究区不同井组注水见效受沉积微相、物源方向和砂体叠置关系等因素的重要影响。

The majority of the discovered oil reservoirs of Yan 9 Oil Group in the Ordos Basin are located in the distributary channel sandbodies of meandering river delta plains. The superposition relationship of single sand body within these sandbodies is complicated and varied, and the influence law of oil development is not clear. Taking the Yan 9 Oil Group in the G162 Area of the Jiyuan Oilfield as an example, the vertical and lateral overlapping relationships of single sand bodies and the connectivity of sand bodies were deeply studied based on core, logging data, testing oil and gas production, production dynamics, and analytical tests. The effect of the superimposition relationships of single sand body on waterflood development was revealed. The results indicate that the vertical superposition relationship of single sand body in the target layer in the study area is mainly in the form of cut-and-stacked, accounting for 64%. The lateral superposition relationship of single sand body is mainly the same channel type and the side-cut type, accounting for 57%. Among these, single sand bodies in contact with cut-and-stacked type and same channel type exhibit good connectivity, while the rest show weak or poor connectivity. Within the distributary channel microfacies parallel to the provenance direction, single sand bodies are mainly in the form of cut-and-stacked type and same channel type, leading to good injection-production correspondence and effective waterflooding effect. In contrast, within the distributary channel microfacies perpendicular to the provenance direction, single sand bodies mainly exhibit superimposed type and side-cut type, resulting in weaker injection-production correspondence and average waterflooding effect. In the wing microfacies of the distributary channel perpendicular to the provenance direction, single sand bodies are primarily isolated, side-cut, and bay-contact types, which correspond poorly to injection-production correspondence, and relatively poor waterflooding effect. So, the effectiveness of waterflood in different well groups in the study area is influenced by factors such as sedimentary microfacies, provenance direction, and superimposition relationships of single sand body.