Decline Curve Analyzer
Forecast a real well to its economic limit: fit exponential and hyperbolic Arps declines with Polyfit and Lsqcurvefit, choose on evidence, and report EUR and remaining reserves with their uncertainty.
The brief
You are the reservoir engineer, reserves reporting
Well OB-14 has produced for two years and its rate is falling. Finance needs a reserves number for the annual report, and the asset manager wants to know how long the well stays above its economic limit of 50 STB/d before deciding whether to fund a workover.
You have the monthly production history and nothing else: no core, no simulation model. That is the everyday situation decline curve analysis was invented for.
You will fit the Arps decline models, choose between them on evidence, forecast the well to its economic limit and report the estimated ultimate recovery (EUR) and remaining reserves. The finished engine powers a forecasting application with a 3D view of how the answer depends on the decline exponent.
- Well
- OB-14, oil producer
- History
- 25 monthly rates, month 0 to 24
- Economic limit
- 50 STB/d
- Days per month
- 30.4375
What you will be able to do
- Integrate a production history for cumulative oil
- Fit an exponential decline by linear regression on the logarithm of rate
- Fit a hyperbolic decline with nonlinear least squares (Lsqcurvefit)
- Choose a model with a quantitative error measure
- Forecast to the economic limit and report EUR and remaining reserves