aRpsDCA (version 1.0.0)

exponential: Arps exponential declines

Description

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

Usage

exponential.q(qi, D, t)
exponential.Np(qi, D, t)

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].

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.

Details

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

See Also

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

Examples

## 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)