An integrated reservoir study represents the one reservoir modeling technique available to a reservoir management team that incorporates ALL of the information available regarding a petroleum reservoir. As such, the integrated study has the potential to provide the team with the highest resolution most accurate description of their field that is currently available. However, that high resolution comes at the expense of a highly complex, data intensive process. This paper was an attempt to simplify and codify the complex process of performing an integrated reservoir study.
The paper presents an overview of the integrated reservoir modeling process including how that process has changed from the early days of reservoir simulation to the present day. Two models are presented that illustrate the study process for a 1980 time frame multi reservoir study and a 2002 time frame geostatistically based compositional reservoir model‥
Emphasis is placed on the changes in workflows from the early models -- simple mapping of properties and manual digitization of maps to simulation model grids -- to the more complex models of today -- with property distributions based on object modeling and geostatistical analysis to distribute reservoir properties.
Through the examples, the paper illustrates the point that reservoir studies have evolved from a time when the geologists and engineers often knew more about their reservoirs than the available modeling tools would allow them to implement in their models – dual porosity and flow across faults, for example – to the point where today we often have the modeling capability to model more complex phenomena than our knowledge of the reservoir may warrant – for example, object modeling with no data on the characteristics of lithofacies in our reservoir, or dual porosity flow models with no data on fracture spacing and distribution.