8. Comments on the results

The two given examples show three aspects of the TDS technique: (1) practical use, (2) accuracy, and (3) self-confirmation.

As shown in the exercises, the process includes defining flow regimes, drawing a few lines, and finally computing the necessary parameters. Contrary to the conventional straight-line method, which requires a plot for each flow regime, TDS technique uses only the pressure and pressure derivative versus time log-log plot. Computations are straight forward.

Table 2 summarizes the main parameters obtained in the two worked examples. The results show a good agreement between the calculated results by TDS technique and the results obtained from commercial software packages, for the field case. The results of the half-fracture length for the synthetic case using TDS technique are even better compared to the input value use to simulate the test. This demonstrates that TDS technique is an accurate methodology which has been also presented in many publications, not only in the list reference but also in others not mentioned here.

The last aspect dealt with is self-confirmation. In the field example, three values of half-fracture length and three values of fractured conductivity were found, and for the synthetic example, two values of half-fracture length were estimated from different equations. All the estimations match with the reference values.


Table 2. Summary of results.
