Further, they showed that the rate-time relationship during afterflow (for a pressure buildup test) or unloading (in a pressure drawdown test) is a function of the pressure drop change with respect to time and a relatively constant wellbore storage coefficient.
For the buildup test, the material balance pressure drop function can be written as
The results are presented in Figures 1 and 2 for the semilog and log-log plots in the case of drawdown test and Figures 3 and 4 for the semilog and log-log plots in the case of buildup test. Besides the deconvolved pressures and their logarithmic derivatives, pressure responses with and without wellbore storage are also plotted on the figures for comparison.
The data are taken from a pressure buildup test and can be reasonably used as field data.
And the last (field) example is a gas condensate well buildup test following a variable rate production history.
Plot of (19) versus [MATHEMATICAL EXPRESSION NOT REPRODUCIBLE IN ASCII] for drawdown and buildup tests, respectively, should be considered more accurate to use as a practical tool for field applications.
The other similarity between (19) and (32) is that the plot of (32) versus [MATHEMATICAL EXPRESSION NOT REPRODUCIBLE IN ASCII] for drawdown and buildup tests, respectively, yields the more accurate results and is usable for practical applications.
In this configuration, the RPA was programmed to cure the experimental compounds at 180 [degrees] C for 10 minutes and using the VTA feature discussed earlier, dropping the temperature down to 40 [degrees] C and holding it there for five minutes before starting the heat buildup test
by oscillating the cured specimen at 12 Hz and 39% strain for six minutes.