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对四川盆地飞仙关组台缘带鲕滩分布规律的认识不清,极大地制约着该区鲕滩气藏的勘探开发成效.以四川东北部飞仙关组为例,分析台缘带鲕滩的发育特征,探索其分布规律.研究发现区内飞仙关组鲕滩沿台地边缘呈NW向展布,并在NE、NW两组基底正断裂交叉处向台地内部呈指状延伸,其延伸方向与台地边缘近于垂直.讨论认为基底断裂同沉积活动形成的古地理格局、沉积古地貌与相对海平面的升降变化共同控制了该区飞仙关组台缘带鲕滩的纵、横分布规律.指出NW向基底断裂的同沉积张裂活动形成了台坳分异的沉积格局,控制了台缘带及台缘带鲕滩相带展布;NE向基底断裂的同沉积正断活动加剧了台地边缘带的沉积地貌分异,台缘带鲕滩发育于NE-SW向基底断裂“断隆”地貌高地,并向台地内部延展,形成“北西控带、北东修饰”的断控型台缘鲕滩指状窄相带分布规律.考虑相对海平面升降变化对鲕滩沉积厚度及沉积范围的叠加影响,总结了台缘鲕滩的分布模式.
The understanding of the distribution of oolitic beach in the Feixianguan Formation of the margin of the Sichuan Basin is not clear, which greatly restricted the exploration and development of the oolitic beach gas reservoir in the area. Taking the Feixianguan Formation in northeastern Sichuan as an example, The results show that the oolitic beach in Feixianguan Formation of the area is distributed in the NW direction along the platform edge and extended towards the interior of the platform at the intersection of the normal and the basement of NE and NW, The extension direction is close to vertical with the edge of the platform.It is considered that the palaeogeographical pattern formed by the basement faulting and sedimentary activity, the change of sedimentary paleogeomorphology and the relative sea level rise and fall jointly control the vertical and horizontal of the oolitic beach in Feixianguan formation in this area It is pointed out that the NW-trending basement faults are formed by synsedimentary zonation, and the depositional pattern of the depression is formed, controlling the distribution of oolitic beach facies belts in the platform margin and platform margin. Which aggravates the differentiation of sedimentary landscapes in the marginal zone of the platform. The oolitic beach in the marginal zone develops from NE-SW to basement rupture and uplifts to the interior of the platform, forming a “northwest control belt, ”Type of controlled edge oolitic beach finger narrow phase distribution law Superimposing the relative sea-level change and influence on the thickness of the deposition in the deposition of oolitic, summarizes the distribution pattern of the platform edge oolitic beach.