changes.mady.by.user Arthur Aslanyan (Nafta College)
Saved on Mar 23, 2019
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{\rm w} = 1 - \frac{r_w^2}{r_e^2} \approx 1
p(t,r) \approx p_i - \frac{q_t}{V_e \, \phi \, c_t} \, t + \frac{q_t}{4\pi \sigma} \bigg[ 2 \ln \frac{r}{r_e} - \frac{r^2}{r_e^2} + 1 \bigg] , \quad r_{wf} < r \leq r_e
p_{wf}(t) \approx p_e(t) - \frac{q_t}{2 \pi \sigma} \, \left[ \ln \frac{r_e}{r_w} - 0.5 + S \right]
p_e(t) =\approx p_i - \frac{q_t}{V_e \phi c_t}t