exponential: Arps exponential declines

In aRpsDCA: Arps Decline Curve Analysis in R

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].

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

## 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)

Example output

 [1] 1000.0000  991.8317  983.7301  975.6946  967.7249  959.8202  951.9800
 [8]  944.2040  936.4914  928.8418  921.2547  913.7296  906.2660  898.8633
[15]  891.5211  884.2389  877.0161  869.8524  862.7471  855.6999  848.7103
[22]  841.7778  834.9019  828.0821  821.3181  814.6093
[1] 46707.16

aRpsDCA documentation built on May 2, 2019, 9:42 a.m.