摘要
针对鄂尔多斯盆地二叠系山西组1段(山1段)—下石盒子组8段(盒8段)粗相带砂体大面积分布特征,通过古地理背景分析和大量岩心观察,提出山1段—盒8段具有"洪水成因型"辫状河三角洲沉积特征。借助水槽模拟实验对"洪水成因型"辫状河三角洲沉积模式进行验证,实验结果表明宽缓的地貌沉积背景、湖水进退往复、强水动力作用与充足的沉积物供给是砂体大面积分布的主要因素。在较干旱的气候条件下,多期次洪水的接力搬运可使粗粒级砂岩向湖盆腹部长距离延伸,形成横向广覆式分布、纵向叠合连片的大面积辫状河—三角洲砂体。
Large areas of sand bodies are distributed in the coarse facies of the first member of Shanxi Formation （Member Shanl ） and eighth member of Lower Shihezi Formation （Member He 8） in the Permian in Ordos Basin. A deposition mode of flood-induced brai- ded river delta from Member Shanl to Member He 8 is proposed based on paleo-geographic analysis and extensive core observations. The proposed depositional mode is verified via a tank simulation experiment. Results show that broad flat landform, lake level fluctu ations, strong hydrodynamic force, and sufficient sediment supply are the main factors responsible for the large-area distribution of the sand bodies. Under arid climatic conditions, successive transportation by multi-stage flood enables the long-distance expansion of coarse sandstone toward the belly of the lake basin, resulting in the formation of large-area braided rive^delta sand bodies character ized by wide distribution and vertical overlap.
出处
《石油学报》
EI
CAS
CSCD
北大核心
2013年第S01期120-127,共8页
Acta Petrolei Sinica
基金
国家重大科技专项"中国大型气田形成条件
富集规律及目标评价(二期)"(2011ZX05007)资助
