GEOLOGIC MODELING FOR OUTCROP RESERVOIR OF CONTINENTAL BASIN AND THE CONCEPTUAL SYSTEMS

The geologic modeling for outcrop reservoirs depends on the clarification of the characteristic heterogeneity of reservoirs,including the depositional heterogeneity,diagenetic heterogeneity,and the heterogeneity of porosity and permeability.The heterogeneity of resevoirs can be studied on three scales (macroscopic scale,mesoscopic scale and microscopic scale).From the study of depositional heterogeneity on different scales,the essential procedure is to model the internal architectural frame,for which it is significant to complement and improve the conceptual order for the internal architectural units and bounding surfaces.This paper indicates the common channel units in various channels,explains the differences of the internal architetural complexity and beddings for different channel sand bodies,and takes the different palaeocurrent energy and depositional modes as the major causes for the differences.Modeling the strong permeation net frame is based on recognition and differentiation of fluid flow units which are building blocks differentiated with isolate barrier beds as the bounding hydrodynamic conditions and are closely related with the internal architectural units of sand bodies in scales and spatial distribution.The study on the heterogeneity of reservoir porosity and permeability of different scales depends on different subjects,for instance,the study for mesoscopic scale is focused on the differences between fluid flow units and the differences between the reservoir lithological facies which formed the architectural units.Deposition significantly dominates the porosity and permeability of reservoirs,but in case of heterogeneous diagenesis in superposition,the integral porosity and permeability will greatly decrease.