The typical industry process for evaluating the economic recovery of hydrocarbon resources using geologic modeling and flow simulation is sequential, involving several disciplines. Each discipline in the chain has a desire to do an excellent job, but may spend more time than is warranted given the quality of the data available at the time.

Speeding up the process while maintaining high quality, RETR is an iterative, parallel work process using a common-scale modeling approach that provides for optimized reservoir models based on the available data. RETR allows an integrated team of geoscientists and engineers to more efficiently extract information from the primary data sets available. The RETR approach is a more parallel process. Instead of waiting until we've built a large, detailed model before we run flow simulations, we build simpler models early to get feedback from flow simulation to guide construction of more detailed subsequent passes.

Fine-scale well data and geologic interpretations are accurately included using Effective Property Simulation (EPSIM).Effective property simulation is a fast way to integrate fine-scale geologic information directly into a flow simulation model. Its application has helped improve history matches for several carbonate reservoirs.

The RETR process begins by modeling large-scale features. We complete an initial pass through flow simulation then add detail with each subsequent pass until we have achieved the highest quality result possible with the data available. The idea is to learn from differences between passes, identify critical factors, incorporate additional data as it becomes available, and better judge when to stop working on a particular issue. Finally, because the RETR process is designed to accommodate change, we can generate multiple models quickly, thereby permitting us to look at multiple scenarios.

The RETR work process significantly reduces cycle time by:

  • focusing an integrated team on a common objective,

  • using common-scale modeling to provide early feedback from flow simulation, and

  • accommodating rapid model updates as additional data become available.


RETR is a process that significantly reduces cycle time for reservoir evaluation. The process was developed by a team of geoscientists and engineers at ExxonMobil. Our team's challenge was to produce quality reservoir evaluations that incorporate all available data, but significantly faster. We were looking for a step-change reduction in cycle time. The business impact of meeting this challenge was to improve economics from discovery to development and provide fast responses to change over the life cycle of a resource.

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