THE HIGH-RESOLUTION SEQUENCE STRATIGRAPHIC FEATURE OF YANCHANG FORMATION IN XIFENG OILFIELD, ORDOS BASIN
鄂尔多斯盆地西峰油田延长组高分辨率层序地层学研究

On the basis of a comprehensive study of core, log well and outcrop profile, taking the the high resolution sequence stratigraphic theory as a direction, the detailed analysis on the subdivision of different orders of the base-level cycles in Yanchang formation has been performed and a corresponding high resolution sequence framework has been established in Xifeng oilfield, Ordos basin. Yanchang formation can be divided one super-long, 5 long, 13 middle and 36 short base-level cycles. The short base-level may be divided two types of cycles that consist of six subtypes. The middle and long base-level cycles are usually of symmetric structures. The authors analyse the relationship between the stacking pattern of different orders of the base-level cycles and the distribution and evolution law of sediment facies.