A new integrated approach of natural fracture modelling to improve historical matching and prediction for Devonian carbonate reservoirs in Nenetskoye oil field, Russia

Tóm tắt

Natural fractures associated with karst systems certainly exist in a tight Devonian carbonate reservoir of the study field with primary porosity and permeability typically less than 3% and 1mD, respectively. Up to now, several workflows have been implemented to model natural fractures and karst networks; unfortunately, existing results cannot be used for managing the field in the future. This paper presents a new integrated approach to build the 3D geological model and simulation for Devonian carbonate reservoirs based on geology, geophysics and production data. With two kinds of reservoir porosity (primary and secondary porosity), the conventional stochastic pixel-based method is applied to populate the porosity and permeability distribution of matrix while the objective-based method is used to model vuggy affected cells along fractured zones which were defined from seismic curvature attributes. The properties of fracture corridors are predicted from the power law function of core, well and seismic data, which are consequently modelled by the Discrete Fracture Network (DFN) method and upscaled by ODA’s method. The approach reflects better in matching based on 5 years of production and pressure history. Finally, various development scenarios are investigated.