Rock volume is a sum of rock matrix volume and total pore volume :| LaTeX Math Block |
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| V = V_m + V_t = (1-\phi_t) V + \phi_t V
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where | LaTeX Math Block |
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| \phi_t = \frac{V_t}{V} |
Total pore volume is a sum of shale-bound water and fre fluid volume (water and hydrocarbons):| LaTeX Math Block |
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| V_t = \phi_t V = V_e + V_{wb} = \phi_e V + s_{wb} V_t |
where | LaTeX Math Block |
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| V_e = V_t (1 - s_{wb}) |
Отсюдаand therefore: | LaTeX Math Block |
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| \phi_e = \phi_t (1 - s_{wb}) |
и
Totalk volume of water is a sum of shale-bound water Общий объем воды в порах складывается их связанной глинами воды и свободной воды в порах and free water :| LaTeX Math Block |
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| V_{wt} = V_{wb} + V_{wf} |
and relates to и выражатся через общий объем поры следующим образом as:| LaTeX Math Block |
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| s_{wt} V_t = s_{wb} V_t + s_w V_e = s_{wb} V_t + s_w V_t (1 - s_{wb}) |
откудаor | LaTeX Math Block |
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| s_{wt} = s_{wb} + s_w (1 - s_{wb}) |
иwhich gives an explicit formula for formation water saturation: | LaTeX Math Block |
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| s_w = \frac{s_{wt} - s_{wb}}{ 1 - s_{wb}} |
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