IPR curve
One well test turned into an inflow performance curve, a productivity index and an absolute open flow.
Production & lift
Decline curve analysis
Paste a rate history and get an Arps fit — qi, Di and b — with the time to the economic limit, remaining reserves and an EUR.
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How it is calculated
- Exponential fits ln q against t; harmonic fits 1/q against t; both are one regression.
- Hyperbolic scans b from 0.05 to 1.5 and linearises q^(−b) against t at each candidate, keeping the b with the lowest residual sum of squares.
- On "best fit" the three models compete on residual, so the answer is whichever describes the data rather than whichever was assumed.
- Reserves integrate the chosen Arps form analytically down to the economic rate; EUR adds the cumulative you enter.
Standards it speaks
Where this stops being true
Arps is an empirical curve, not physics. It assumes boundary-dominated flow at constant bottom-hole pressure with no operating change — so a fit over a period containing a workover, a compressor start-up or a choke change describes the intervention, not the reservoir. In unconventional wells the early transient period fits with b well above 1, which is mathematically unbounded and gives reserves that cannot exist; those wells need a terminal exponential decline imposed, and this tool does not impose one for you.
The capability that automates this
Related tools
Gas-lift injection optimisation
Fit a gas-lift performance curve through your injection tests and find both the technical peak and the point where the next MSCF stops paying for itself.
Static gradient & bottom-hole pressure
Bottom-hole pressure from a wellhead reading — a liquid gradient for oil and water, and a stepwise gas-column integration for gas.
Build-up test — permeability & skin
A Horner plot from your shut-in pressures, with the semilog slope turned into permeability, skin, p* and flow efficiency.