【摘要】 松辽盆地北部昌德地区白垩系泉四段砂体分布广泛，砂体类型多样且存在差异，影响后期致密砂岩油气藏的勘探开发。利用岩心、测井、古生物和地球化学资料，探讨昌德地区泉四段砂体结构特征及控制因素。结果表明：昌德地区泉四段发育浅水三角洲—浅湖沉积体系。浅水三角洲平原亚相主要发育分流河道和决口扇沉积，分流河道见大量小型槽状交错层理、楔状交错层理和平行层理等强水动力构造；浅水三角洲前缘亚相主要发育水下分流河道和席状砂沉积，见波状层理和砂纹层理等弱水动力构造。浅水三角洲平原亚相对前缘砂体更富集且砂地比更高。昌德地区泉四段砂体垂向结构表现为块状切叠型、块状叠置型、层状叠置型和单一孤立型四类结构样式，横向结构表现为侧向切割、侧向对接、泥岩间隔三种接触关系，不同砂体结构的物性存在差异。古气候变化影响沉积物供给量，基准面变化影响可容纳空间，河流和湖浪作用随河流向湖盆推进砂体持续改造，古气候、基准面升降、水动力因素共同影响砂体结构。该结果为浅水三角洲油气藏开发提供指导。更多还原

【Abstract】 In response to the widespread distribution and diverse types of sand bodies in the fourth member of the Cretaceous Quantou Formation in the Changde Area of the Northern Songliao Basin,which affect the exploration and development of tight sandstone oil and gas reservoirs in the later stage.This study uses core,logging,paleontological and geochemical data to explore the structural characteristics and controlling factors of sand bodies in the fourth member of the Quantou Formation in the Changde Area.The results indicate that the fourth member of the Quantou Formation in Changde Area has developed a shallow water delta shallow lake sedimentary system.The shallow water delta plain subfacies mainly develop distributary channels and crevasse fan sediments.The distributary channels exhibit a large number of small trough shaped cross bedding,wedge-shaped cross bedding,and parallel bedding,among other strong hydrodynamic structures.The shallow water delta front subfacies mainly develop underwater distributary channels and sheet-like sand deposits,with weak hydrodynamic structures such as wavy bedding and sand ripple bedding.Shallow water delta plains are relatively more enriched in front edge sand bodies and have a higher sand to land ratio.The vertical structure of the fourth member of the Quantou Formation in Changde Area shows four types of stacking styles:block cutting stacking,block stacking,layered stacking,and single isolation.The horizontal structure shows three types of contact relationships:lateral cutting,lateral docking,and mudstone spacing.The physical properties of different sand body structures are different.The changes in ancient climate affect the supply of sediment,changes in base level affect the available space,and the effects of rivers and lake waves promote the construction and destruction of sand bodies in the lake basin along with the river flow.The combination of ancient climate,base level rise and fall,and hydrodynamics affects the structure of sand bodies.This result provids assistance for the development of shallow water delta oil and gas reservoirs.更多还原