6. Other estimations

The expressions for determination of the naturally fractured reservoir parameters cannot be included in this chapter for space reasons. However, they can be found in [15, 16], which also used intersection points and maximum and minimum data read from the pressure and pressure derivative curve.

Radial flow regime may be absent in short tests run in fractured wells with the sole purpose of determining fractured parameters. For these cases, the skin factor can be estimated from any of the two empirical correlations presented by [27]

$$s = \ln\left[\binom{\nu}{w}\frac{\mathbf{1}\not\le 2173}{\chi\_f} \quad - \frac{\mathbf{3}\cdot\mathbf{3}1739}{k\_f w\_f}\right] \tag{34}$$

and

$$s = \ln \frac{r\_w}{x\_f} + \frac{1.65 - 0.32u + 0.11u^2}{1 + 0.18u + 0.064u^2 + 0.005u^3},\tag{35}$$

where

$$
\mu = \ln \mathcal{C}\_{\mathcal{f}\mathcal{D}}.\tag{36}
$$

Additionally, fracture conductivity can be read from the plot given in Figure 2. Finally, space reasons prevent including TDS technique for fractured wells in unconventional shale formations. The reader is referred to [23–26].
