There are few approaches to match the Arps decline to the historical data:

Unconstrained matching
Constrained matching:
- Match the value of the initial rate $\begin{array}{l}q^*(t=0) = q_0\end{array}$
- Match the value of the current rate $\begin{array}{l}q^*(t=t_N) = q_N\end{array}$
- Match the value of the current cumulative $\begin{array}{l}Q^*(t=t_N) = Q_N\end{array}$
- Match the value of the current rate and cumulative $\begin{array}{l}q^*(t=t_N) = q_N\end{array}$ , $\begin{array}{l}Q^*(t=t_N) = Q_N\end{array}$

To ensure the smooth transition from historical data $\begin{array}{l}[(t_1,q_1)... (t_N, q_N)]\end{array}$ to the production forecasts in future time moments $\begin{array}{l}[(t_{N+1},q_{N+1}), ...]\end{array}$ one may wish to constrain the model by firm matching the production at the last historical moment $\begin{array}{l}(t_N, q_N)\end{array}$ which leads to the following form of Arp's model:

Hyperbolic Production Decline

Harmonic Production Decline

$\begin{array}{l}b=0\end{array}$

$\begin{array}{l}0< b< 1\end{array}$

$\begin{array}{l}b=1\end{array}$

(1)	$\begin{array}{l}\displaystyle q(t)=q_N \cdot \exp \big[ -D_0 \cdot (t-t_N) \big]\end{array}$

(2)	$\begin{array}{l}\displaystyle q(t) = q_N \cdot \left[ \frac{1+b \cdot D_0 \cdot t_N } { 1+b \cdot D_0 \cdot t } \right]^{1/b}\end{array}$

(3)	$\begin{array}{l}\displaystyle q(t) = q_N \cdot \left[ \frac{1+D_0 \cdot t_N } { 1+ D_0 \cdot t } \right]\end{array}$

(4)	$\begin{array}{l}\displaystyle Q(t) - Q_N = [ q_N - q(t)] \, \tau_0\end{array}$

(5)	$\begin{array}{l}\displaystyle Q(t) - Q_N = \frac{q_N^b \, (\tau_0 + b \, t_N)}{1-b} \left[ q_N^{1-b} - q^{1-b}(t) \right]\end{array}$

(6)	$\begin{array}{l}\displaystyle Q(t) - Q_N = q_N \, (\tau_0 + t_N) \cdot \ln \frac{q_N}{q(t)}\end{array}$

Page tree

See Also

Page tree

DCA Arps Matching @model

See Also