Characterization of a Carbonate Reservoir on a Platform

The upper Cretaceous Shiranish reservoir of Oudeh oilfield is mainly porous grainstone deposited on carbonate open platform margin. Sedimentary microfacies study showed that the high quality reservoir mainly deposited on the platform shoal facies. The reservoir has high lateral and vertical heterogeneity and variability. Adopting the global optimization of the fast inversion algorithm, we use model based inversion to predict the spatial distribution of high quality reservoir, which can integrate the advantages of seismic and high vertical resolution of logging data to improve the reliability of reservoir prediction. In addition, there are ‘Secondary water bodies’ developed in this area with thickness of 1-5 meters, showing features of sudden drop on resistivity curve, low density and high acoustic. Drilling has showed that wells encountered ‘Secondary water body’ would have quick water flooding. We used reservoir characteristics reconstruction technique and model based inversion to predict these bodies, the method can not only reach the high resolution that predict these parts but also meet the requirement of horizontal reliability. The seismic inversion results coincide with the features of structure, deposition and strata of the studied area, and can be used as basis for the following well deployment and lower development risk.