构造对东营凹陷深层砂体发育的控制作用

充分利用钻井和地震资料，结合前人研究成果，确定控制东营凹陷深层砂体发育的主要因素为断层和古沟槽。断层对东营凹陷深层砂体发育具关键控制作用，砂体主要沿二级以上断层的下降盘呈裙带状分布，且断层活动强度决定了砂体的沉积厚度，断层落差变化趋势线与砂体厚度变化趋势线相吻合。受北断南超的构造背景控制，东营凹陷深层断裂活动也表现为北强南弱，从而控制了砂体发育由北部的近岸水下扇到中部的辫状河三角洲再到南部的扇三角洲演变。东营凹陷南部缓坡深大断层发育较少，古沟槽对深层砂体的发育具有明显控制作用，主要发育冲沟和断沟2种，以冲沟为主，且沟槽发育具有继承性，从而导致沙四至沙三段发育的扇体在垂向上叠置。最后，根据控砂要素，建立了东营凹陷深层砂体发育模式。

Research on Structures Controlling the Development of Deep Sand Bodies in Dongying Depression

Faults and ancient valley-troughs controlled the development of deep sand bodies in Dongying depression by analyzing borehole data, seismic data and previous conclusion. The fault is key element to control the distribution of sand bodies in the northern part of Dongying depression. The sandstone distributes along downthrown side of main faults like skirt sides. The intensity of the faults activity decided the thickness of sandstone, the changing trend line of the fault throw is consistent with the thickness of sandbodies. The intensity of the faults activity also controlled the facies type of sandbodies. The deep faults activity gradually intensified from north to south in Dongying depression due to the northern-faulted and southern-overlapped structural setting, so the facies type of sandbodies are changed from nearshore subaqueous fans in the northern part to braided river deltas in the middle part and to fan deltas in the southern part. The ancient valley-troughs which include the fault troughs and the incised valley with extensive development obviously controlled the distribution of sandbodies in the southern part of Dongying depression as a result of the lack of the deep-large faults. The developing succession of the ancient valley-troughs resulted in the vertical superposition of sand bodies from Sha 4 member to Sha 3 member. At last, the formation patterns of deep sandbodies in Dongying depression were set up according to controlling factors.