Arps exponential declines

Description

Compute rates and cumulative production values for Arps exponential decline curves.

Usage

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Arguments

qi

initial rate [volume / time], i.e. q(t = 0).

D

nominal Arps decline exponent [1 / time].

t

time at which to evaluate rate or cumulative [time].

Details

Assumes consistent units of time between qi, D, and t. To convert, see the decline-rate conversion functions referenced below.

Value

exponential.q returns the rate for each element of t, in the same units as qi.

exponential.Np returns the cumulative production for each element of t, in the same units as qi * t.

See Also

as.effective, as.nominal, rescale.by.time.

Examples

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## qi = 1000 Mscf/d, Di = 95% effective / year, t from 0 to 25 days
exponential.q(1000, as.nominal(0.95, from.period="year", to.period="day"), seq(0, 25))

## qi = 500 bopd, Di = 3.91 nominal / year, t = 5 years
exponential.Np(rescale.by.time(500, from.period="day", to.period="year"), 3.91, 5)