Page tree

Versions Compared

Key

  • This line was added.
  • This line was removed.
  • Formatting was changed.

...

LaTeX Math Block
alignmentleft
p(t) = p_i + \sum_{\alpha = 1}^{N} \big(left[ q^{(\alpha)}_k - q^{(\alpha-1)}_k \big)right] \cdot p^up_u(t - t_t^{\alpha k})

where

_n{,n}q^{()}_nrate value of -th transient at th wellt_{\alpha k} -th well6n, k = 1.. \ N
1

LaTeX Math Inline
bodyp

(t)

pressure at

LaTeX Math Inline
bodyn
-th well at arbitrary moment of time
LaTeX Math Inline
bodyt

2

LaTeX Math Inline
bodyp_

i

initial pressure at

LaTeX Math Inline
bodyn
-the well

3

LaTeX Math Inline
body

\alpha

= 1 .. N

index number of a transient (period of time where rate was constant) 

LaTeX Math Inline
body

\alpha

N

total number of transients

LaTeX Math Inline
body

n

-

4

LaTeX Math Inline
bodyp^u_{nk} (t)

pressure transient response in

LaTeX Math Inline
bodyn
-th wel to unit-rate production from
LaTeX Math Inline
bodyk
-th well

5
LaTeX Math Inline
body

-uriencoded--t%5e%7B\alpha%7D

starting point of the

LaTeX Math Inline
body\alpha
-th transient in

LaTeX Math Inline
body

k

--uriencoded--q%5e%7B(\alpha)%7D

7

rate value of

LaTeX Math Inline
body

Nnumber of wells in the test

\alpha
-th transient which starts at the time moment 

number of transients in -th well

LaTeX Math Inline
body--uriencoded--t%5e%7B(\alpha)%7D

N_k

LaTeX Math Inline
body

k

p_u(t)

pressure transient response to the unit-rate production

with assumption:

  • LaTeX Math Inline
    bodyq^{--uriencoded--q%5e%7B(-1)}_k %7D = 0
     – for any well , which means that well was shut-in before it started the first transient 
    LaTeX Math Inline
    bodyk \alpha =1.. \ N
     

  • LaTeX Math Inline
    bodyp^up_{nk}(\tauu(t) = 0
     at 
    LaTeX Math Inline
    body\tau < 0
     for any pair of wells 
LaTeX Math Inline
body
t < 0
 which means pressure drop is zero before the well starts unit-rate production


Hence, convolution is using initial formation pressure 

LaTeX Math Inline
bodyp_{i, n}
, unit-rate transient responses of  wells and cross-well intervals 
LaTeX Math Inline
bodyp^u_{nk} (t)
 and rate histories 
LaTeX Math Inline
body \{ q_k (t) \}_{k = 1 .. N}
 to calculate pressure bottom-hole pressure response as function time 
LaTeX Math Inline
bodyp_n(t)
:

...