Despite of terminological similarity there is a big difference in the way Dynamic Modelling, Well Flow Performance and Well Testing define formation pressure and productivity index definition and corresponding analysis. This difference is summarized in the table below:
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| DM | field-average pressure within the 9-cell area | LaTeX Math Block |
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| p_{e9, \ i,j} = \frac{1}{9} \sum_{k=i-1}^{i+1} \sum_{l=j-1}^{j+1} p_{k,l} |
| LaTeX Math Block |
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| p_{e9, \ i,j} = \frac{1}{9} ( p_{i,j}
+ p_{i, \, j+1} + p_{i, \, j-1}
+ p_{i-1, \, j} + p_{i-1, \, j}
+ p_{i-1 \, j-1} + p_{i+1, \, j+1}
+ p_{i-1 \, j+1} + p_{i+1, \, j-1} ) |
| phase flowrate at sandface: | LaTeX Math Inline |
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| body | \{ q_w, \, q_o, \, q_g \} |
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(each fluid phase separately) | phase productivity index:
| LaTeX Math Inline |
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| body | J_ w = \frac{q_q}{p_r - p_{wf}} |
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, | 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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| WFP | field-average pressure within the drainage area | LaTeX Math Block |
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| p_r = \frac{1}{A_e} \iint_{A_e} p(x,y,z) dS |
| surface component flowrate (each fluid component separately) and sometimes liquid flowrate | LaTeX Math Inline |
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| body | q_{\rm liq} = q_W + q_O |
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| fluid component productivity index: | LaTeX Math Inline |
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| body | J_W = \frac{q_W}{p_r - p_{wf}} |
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, | 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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and sometimes liquid productivity index: | LaTeX Math Inline |
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| body | J_{\rm liq} = \frac{q_{\rm liq}}{p_r - p_{wf}} |
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| WT | average pressure value at the boudary of drainage area | LaTeX Math Block |
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| p_e = \frac{1}{L_e} \int_0^{L_e} p(x,y,z) dl |
where is the boundary of drainage area | total flowrate at sandface: | LaTeX Math Inline |
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| 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 Oilor pseudo-components of Compositional Model | 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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