Hierarchical nested simulation approach in reservoir architecture modeling

A hierarchal nested reservoir architecture simulation methodology is proposed to meet the current challenges in reservoir heterogeneity modeling. It matches the architecture geological research principle which is shortened as “hierarchical constraint, pattern fitting and multi-dimension proof”. In this proposed methodology, different modeling approaches are adopted in different stages of architecture analysis, and the result from current architecture analysis is used as constraints and information for next level architecture analysis. The meandering river reservoir architecture modeling is used to illustrate the proposed methodology. The meandering river sand complex is the first modeling stage. The Fluvsim program is updated to characterize the bounding surface of single channel within the channel sand complex. In second stage, a new point bar simulation program, Barsim, is developed. The abandoned channel and the known point bars are assembled together according to the quantity fluvial reservoir architecture model. The spatial vector based program Ihssim is developed to characterize the inclined heterogeneity strata (IHS) inside the point bar sand at third level architecture study stage. Through such an integrated three modeling procedures, the heterogeneity characteristics of a reservoir which is represented by reservoir architecture elements in different scales and hierarchical levels are presented in the final reservoir model.