The base-level cycles in the 8th oil reservoirs of the Yanchang Formation in the Zhenjing region, Ordos Basin:Its bearings to the heterogeneity of the reservoir sandstones

The present paper deals, in the light of high-resolution sequence stratigraphy, with the stacking patterns of the short-term base-level cycles and the heterogeneity of the reservoir sandstones from the 8th oil reservoirs in the Zhenjing region, Ordos Basin. Six heterogeneity models are then constructed. The short-term base-level cycles have the dominant impact on the intraformational heterogeneity while the medium-and long-term cycles on the interformational heterogeneity of the reservoir sandstones.