论文部分内容阅读
为厘清坳陷湖盆缓坡背景下形成的浊积体的沉积特征及分布规律,选取松南西斜坡缓坡带晚白垩世青一二段发育的滑塌浊积体作为研究对象,根据岩心和钻测井资料,并结合地震解释,对其沉积相及展布规律进行了研究.该区主要发育三角洲前缘-滑塌浊积岩体系,作为油气储层的滑塌浊积岩可以识别出浊积水道、浊积舌状体、浊积席状砂3种微相类型;在沉积相对比与平面展布特征分析的基础上建立了坳陷湖盆缓坡带浊积体沉积发育模式,认为研究区发育的浊积岩主要为线物源、砂泥质浊积岩沉积模式;与断陷盆地发育的三角洲前缘滑塌浊积岩相比,由于大型坳陷盆地缓坡带断裂作用弱,构造坡折带坡度小,三角洲前缘沉积物再搬运作用相对较弱,浊积岩规模相对较小、粒度较细.此外,与断陷盆地不同,坳陷湖盆内滑塌浊积岩主要发育于三级旋回(层序)基准面上升期,在四级旋回内浊积岩的富集也与湖侵作用密切相关.
In order to clarify the sedimentary characteristics and distribution of turbidites formed in the gentle slope of the depression lacustrine basin, the slump turbidite bodies developed in the second and the fourth grapes of the Late Cretaceous in the western slope of Songnan slope were selected as the research objects. According to the core and drilling measurements Well data, and combined with seismic interpretation, the sedimentary facies and distribution law were studied.The delta front-slump turbidite system is mainly developed in this area, and turbidite as oil and gas reservoir can be identified as turbidite Watercourse, turbidite tongue, and turbid sandstone sand. Based on the analysis of depositional contrast and planar distribution, the sedimentary model of turbidite sediment in the gentle slope of the lacustrine basin was established. The turbidites developed in this area are mainly sedimentary models of line-source and sand-muddy turbidite. Compared with the delta front turbidite with developed faulted basins, due to the weak faulting of the gentle slope zone in the large depression basin, Slope slope is small, the delta front sediment re-transport relatively weak, relatively small turbidite size, fine grain size.In addition, different from the rift basin, slump turbidity sedimentary basin in the main depressions In the third cycle (sequence) basement rise period, at Enrichment turbidites in the scale cycle is also closely related to the transgression lake.