Difference between revisions of "Decline Curve Analysis"

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==Brief==
 
==Brief==
  
[[Decline Curve Analysis]] '''DCA''' is an empirical method for rate decline analysis and rate forecasting published by Arps in '''1945''' <ref name=Arps />.
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[[Decline Curve Analysis]] '''(DCA)''' is an empirical method for rate decline analysis and rate forecasting published by Arps in '''1945''' <ref name=Arps />.
  
 
[[Decline Curve Analysis|DCA]] is applied for [[Well]]s and [[Reservoirs]] production forecasting.
 
[[Decline Curve Analysis|DCA]] is applied for [[Well]]s and [[Reservoirs]] production forecasting.

Revision as of 16:00, 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)}}

Discussion

If one has a need to convert decline factor Di to the actual annual decline in %:

if\ b > 0, a =  (1 - (1 + b\ D_i)^{- 1 / b}) \times 100
if\ b = 0, a =  (1 - e^{-D_i}) \times 100

Nomenclature

 a = annual decline, %
 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.