Despite of terminological similarity there is a big difference in the way 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 pressure | Flow rate | Prroducivity Index |
|---|
| DM | WFP | | field-average pressure within the drainage 9-cell area | | phase flowrate at sandface: surface liquid rate | LaTeX Math Inline |
|---|
| body | \{ q_Ww, \, q_Oo, \, q_Gg \} |
|---|
|
(each fluid component phase separately) | | phase productivity index:
| LaTeX Math Inline |
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| body | J_ W w = \frac{q_Wq}{p_R - p_{wf}} |
|---|
|
, | LaTeX Math Inline |
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| body | J_O o = \frac{q_Oo}{p_R - p_{wf}} |
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|
, | LaTeX Math Inline |
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| body | J_G o = \frac{q_Go}{p_R - p_{wf}} |
|---|
|
|
|---|
| WTWFP | | field-average pressure value at within the boudary of drainage area | | surface liquid rate total flowrate at sandface: | LaTeX Math Inline |
|---|
| body | q_t = B_w \, \{ q_W + B_o \, q_O + B_g \, ( q_G - R_s q_O) |
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|
– for Black Oil(each fluid component separately) | | fluid component productivity index: | LaTeX Math Inline |
|---|
| body | qJ_t W = B_w \, frac{q_W + \frac}{Bp_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 , | LaTeX Math Inline |
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| body | qJ_t = B_w \, q_W + O = \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 |
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|
– for pseudo-components of Compositional Model , | ttotal multiphase productivity index | LaTeX Math Inline |
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| body | J_t G = \frac{q_tG}{p_e R - p_{wf}} |
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|
| WFP | Well Testing |
|---|
| WT | Formation pressure | | field-average pressure within the drainage area | LaTeX Math Inline |
|---|
body | A_ | | average pressure value at the boudary of drainage area | Flow rate | | surface liquid rate (each fluid component separately) | | total flowrate at sandface: | LaTeX Math Inline |
|---|
| body | q_t = B_w \, q_W + B_o \, q_O + B_g \, ( q_G - R_s q_O) |
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|
– for Black Oil| LaTeX Math Inline |
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| body | q_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 |
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|
– for Volatile Oil| LaTeX Math Inline |
|---|
| body | q_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 |
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|
– for or pseudo-components of Compositional Model | Prroducivity Index | | | LaTeX Math Inline |
|---|
body | J_W = \frac{q_W}{p_R - p_{wf}} | , | LaTeX Math Inline |
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| body | J_O = \frac{q_O}{p_R - p_{wf}} |
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|
, | LaTeX Math Inline |
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| body | J_G = \frac{q_G}{p_R - p_{wf}} |
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|
| total multiphase productivity index: | LaTeX Math Inline |
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| body | J_t = \frac{q_t}{p_e - p_{wf}} |
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