Continuous improvements in reservoir simulation software and the
availability of high performance computing equipment are making the use of
simulation models commonplace for field development and planning purposes.
Naturally, this trend has also increased interest in the use of reservoir
simulation model results in the oil and gas reserves estimation process.
As simulation specialists who work in a primarily reserves-evaluation
company, the authors are routinely asked to evaluate, and in many cases
incorporate, simulation results in the reserves estimation process. In
addition, the authors are required to opine on the approach and tactics used by
clients while they incorporate numerical models in their reserves bookings.
Because limited published discussion exists on this topic, the purpose of this
paper is to provide some examples of the approach used by the authors. We
believe this approach to be appropriate and within the spirit of reserves
interpretation as used by typical reserves regulatory bodies such as the U.S.
Securities and Exchange Commission (SEC).
Papers previously published have discussed the use of models in the reserves
process, including the evaluation of the models themselves (Palke and Rietz
2001; Rietz and Usmani 2005). In contrast, this paper provides three case
studies that illustrate how results from various models have been used to
assist in quantifying reserves. Two of the examples are based on
history-matched models, while the third focuses on a pre-production reservoir
where no adequate history is available and probabilistic methods were
incorporated to help understand the uncertainty in the forecasts.
While there is no "cookbook" or step-by-step procedure for using
simulation results to estimate reserves, the case studies presented in this
paper are intended to both show some examples and also spark some debate and
discussion. Undoubtedly there will be some disagreement with our techniques,
but an open discussion should prove to be beneficial for both reserves
evaluators and simulation specialists.
© 2009. Society of Petroleum Engineers
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- Original manuscript received:
27 July 2007
- Meeting paper published:
11 November 2007
- Revised manuscript received:
14 May 2008
- Manuscript approved:
3 June 2008
- Published online:
2 March 2009
- Version of record:
26 February 2009