Decline curve and simple economics
Illustrative, not for reserves reporting or investment decisionsRuns in your browser; nothing is uploaded
Paste monthly production for one well, or load a CSV file. The file is read in your browser and never sent anywhere. Two columns: a month (2024-03, 202403, Mar 2024, or just 1, 2, 3 …) and the production.
Dots: your data from the peak onward. Line: fitted curve and forecast.
Methods
Arps hyperbolic decline q = qi / (1 + b·Di·t)^(1/b), switching to exponential decline at a terminal rate Dmin. Rate is per day, Di is nominal annual decline. The fit uses least squares on log rate from the highest month onward, with b searched between 0 and 2; it warns when b is poorly determined. The forecast starts at the end of your data. Economics are pre-tax and pre-royalty: volume × (price − opex) minus fixed costs, discounted monthly. Units are whatever you enter (bbl/d with $/bbl, or mcf/d with $/mcf).
How reliable is this? See our backtest on about 1,900 Canadian wells: typical error on a 12-month forecast was 13 to 17% with four years of history, and about twice that with two years.