GLOSSARY

Page tree

Versions Compared

Old Version 57

changes.mady.by.user Arthur Aslanyan (Nafta College)

Saved on

compared with

New Version 58

changes.mady.by.user Arthur Aslanyan (Nafta College)

Saved on

Key

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

...

But when field-average formation pressure is above bubble-point 

LaTeX Math Inline
bodyp_R > p_b
 (which means that most parts of the drainage area are saturated oil) the PI can be farily approximated  by some analytical correlations.




Note
titleImportant Note


expand

Excerpt Include

title
Definition specifics on formation pressure and productivity index in between Dynamic Modelling, Well Flow Performance and Well Tests

Despite of terminological similarity there is a big difference in the way

Definition specifics on formation pressure and productivity index in between Dynamic Modelling,

 

Well Flow Performance

 and Well Testing deal with formation pressure and flowrates which results in a difference in productivity index definition and corresponding analysis.

This difference is summarized in the table below:

Formation pressureFlow ratePrroducivity IndexDM

LaTeX Math Inline
bodyp_{R9}

field-average pressure within the 9-cell area

LaTeX Math Inline
bodyA_{e9}

LaTeX Math Inline
bodyq

phase flowrate at sandface:

LaTeX Math Inline
body\{ q_w, \, q_o, \, q_g \}

(each fluid phase separately)

LaTeX Math Inline
bodyJ

phase productivity index:

LaTeX Math Inline
bodyJ_ w = \frac{q_q}{p_R - p_{wf}}
,
LaTeX Math Inline
bodyJ_o = \frac{q_o}{p_R - p_{wf}}
,
LaTeX Math Inline
bodyJ_o = \frac{q_o}{p_R - p_{wf}}
WFP

LaTeX Math Inline
bodyp_R

field-average pressure within the drainage area

LaTeX Math Inline
bodyA_e

LaTeX Math Inline
bodyq

surface liquid rate

LaTeX Math Inline
body\{ q_W, q_O, q_G \}

(each fluid component separately)

LaTeX Math Inline
bodyJ_s

fluid component productivity index:

LaTeX Math Inline
bodyJ_W = \frac{q_W}{p_R - p_{wf}}
,
LaTeX Math Inline
bodyJ_O = \frac{q_O}{p_R - p_{wf}}
,
LaTeX Math Inline
bodyJ_G = \frac{q_G}{p_R - p_{wf}}

WT

LaTeX Math Inline
bodyp_e

average pressure value at the boudary of drainage area

LaTeX Math Inline
bodyA_e

LaTeX Math Inline
bodyq

total flowrate at sandface:

LaTeX Math Inline
bodyq_t = B_w \, q_W + B_o \, q_O + B_g \, ( q_G - R_s q_O)
– for Black Oil

LaTeX Math Inline
bodyq_t = B_w \, q_W + \frac{B_o - R_s B_g}{1 - R_v R_s} \, q_O + \frac{B_g - R_v B_o}{1 - R_v R_s} \, q_G
– for Volatile Oil

or

LaTeX Math Inline
body\{ W, \, O, \, G \}
pseudo-components of Compositional Model

LaTeX Math Inline
bodyJ_t

total multiphase productivity index: LaTeX Math InlinebodyJ_t = \frac{q_t}{p_e - p_{wf}}

and Well Tests



Anchor
VLP
VLP

VLP – Vertical Lift Performance

...