Difference between revisions of "Decline Curve Analysis"

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(Nomenclature)
(Nomenclature)
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=== Nomenclature ===
 
=== Nomenclature ===
:<math> b </math> = decline parametr, dimensionless
+
:<math> b </math> = decline curve parametr, dimensionless
 
:<math> D_i </math> = decline factor per time t, dimensionless
 
:<math> D_i </math> = decline factor per time t, dimensionless
 
:<math> q_i </math> = initial rate, any rate units applies
 
:<math> q_i </math> = initial rate, any rate units applies

Revision as of 15:49, 26 October 2017

Brief

Decline Curve Analysis DCA is an empirical method for rate decline analysis and rate forecasting published by Arps in 1945 [1].

DCA is applied for Wells and Reservoirs production forecasting.

Math & Physics

Note Rate Cumulative
Hyperbolic decline, 0 < b < 1 [2] q(t) = \frac{q_i}{(1+b\ D_i\ t)^{1/b}}  Q = \frac{q^b_i}{D_i\ (1-b)} (q^{1-b}_i-q(t)^{1-b})
Exponential decline, b = 0 q(t) = {q_i}^{-D_i\ t} Q = \frac{q_i-q(t)}{D_i}
Harmonic decline, b = 1 q(t) = \frac{q_i}{1+D_i\ t} Q = \frac{q_i}{D_i} ln{\frac{q_i}{q(t)}}

Nomenclature

 b = decline curve parametr, dimensionless
 D_i = decline factor per time t, dimensionless
 q_i = initial rate, any rate units applies
 q(t) = rate at time t, any rate units applies
 t = forecast time, days

References

  1. Arps, J. J. (1945). "Analysis of Decline Curves"Paid subscription required. Transactions of the AIME. Society of Petroleum Engineers. 160 (01). 
  2. "KAPPA Dynamic Data Analysis (DDA) book"Paid subscription required.