Carbonate Sedimentary Facies and Sedimentary Model of the Sadi Formation in W Oilfield

The Cretaceous bioclastic limestone reservoirs are widely developed in the Middle East, and ramp carbonate reservoirs are developed in the Sadi Formation of W Oilfield. The reservoirs have strong heterogeneity. Currently, there are problems such as rapid pressure drop and low production, delayed energy supplementation, and low producing degree. Moreover, the study on the sedimentary characteristics and reservoir distribution patterns is still shallow. Therefore, it is of great significance to clarify the sedimentary evolution characteristics and sedimentary models of the Sadi Formation for the further study of reservoir distribution and establishment of the three-dimensional geological model. This paper uses the residual thickness method to restore the paleogeomorphic of the Sadi Formation. Based on the analysis of ancient landforms, combined with the study of cores, thin sections, logging facies and seismic facies, the sedimentary microfacies of the Cretaceous Sadi Formation were identified, the sedimentary evolution laws were revealed, and the development model of the Sadi Formation was established. The study results indicate that the grain-shoal facies of inner ramp are a favorable zone and is most prone to developing high-quality reservoirs. This study achievement has important theoretical value in clarifying the heterogeneity characteristics and genesis of Cretaceous bioclastic limestone reservoirs in the Middle East, and has practical guiding significance for the development and well deployment of oilfield.