Summary
Most reservoir-simulation studies are conducted in a static context--at a
single point in time using a fixed set of historical data for history matching.
Time and budget constraints usually result in significant reduction in the
number of uncertain parameters and incomplete exploration of the parameter
space, which results in underestimation of forecast uncertainty and
less-than-optimal decision making. Markov Chain Monte Carlo (MCMC) methods have
been used in static studies for rigorous exploration of the parameter space for
quantification of forecast uncertainty, but these methods suffer from long
burn-in times and many required runs for chain stabilization.
In this paper, we apply the MCMC in a real-time reservoir-modeling
application. The system operates in a continuous process of data acquisition,
model calibration, forecasting, and uncertainty quantification. The system was
validated on the PUNQ (production forecasting with uncertainty quantification)
synthetic reservoir in a simulated multiyear continuous-modeling scenario, and
it yielded probabilistic forecasts that narrowed with time. Once the continuous
MCMC simulation process has been established sufficiently, the continuous
approach usually allows generation of a reasonable probabilistic forecast at a
particular point in time with many fewer models than the traditional
application of the MCMC method in a one-time, static simulation study starting
at the same time.
Operating continuously over the many years of typical reservoir life, many
more realizations can be run than with traditional approaches. This allows
more-thorough investigation of the parameter space and more-complete
quantification of forecast uncertainty. More importantly, the approach provides
a mechanism for, and can thus encourage, calibration of uncertainty estimates
over time. Greater investigation of the uncertain parameter space and
calibration of uncertainty estimates by using a continuous modeling process
should improve the reliability of probabilistic forecasts significantly.
© 2010. Society of Petroleum Engineers
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History
- Original manuscript received:
7 July 2009
- Meeting paper published:
3 February 2009
- Revised manuscript received:
8 May 2010
- Manuscript approved:
13 May 2010
- Published online:
12 August 2010
- Version of record:
24 August 2010