Changes

The surface shut-in and flowing pressure measurements are converted to bottomhole conditions and a log-log plot of <math>\bar{p}^{2} - p_{\rm wf}^{2}</math> versus flow rate, ''q'', is generated ([[:file:production-testing_fig2.png|Figure 2]]). The four points define a straight line with a slope that is generally between 0.5 and 1.0. This straight line is extrapolated to determine gas flow rate at a point where the flowing bottomhole pressure is zero; this rate is referred to as the absolute open flow (AOF) potential of the well.

The surface shut-in and flowing pressure measurements are converted to bottomhole conditions and a log-log plot of <math>\bar{p}^{2} - p_{\rm wf}^{2}</math> versus flow rate, ''q'', is generated ([[:file:production-testing_fig2.png|Figure 2]]). The four points define a straight line with a slope that is generally between 0.5 and 1.0. This straight line is extrapolated to determine gas flow rate at a point where the flowing bottomhole pressure is zero; this rate is referred to as the absolute open flow (AOF) potential of the well.

Multi-point test data can also be used to estimate permeability using a variable rate flow test analysis.<ref name=pt09r20>Odeh, A. S., Jones, L. G., 1965, Pressure drawdown analysis, variable-rate case, in Pressure Analysis Methods: Dallas, TX, American Institute of Mining, Metallurgical and Petroleum Engineers, Society of Petroleum Engineers Reprint Series No. 9, 256 p.</ref> For gas wells, the data are plotted as

Multi-point test data can also be used to estimate permeability using a variable rate flow test analysis.<ref name=pt09r20>Odeh, A. S., and L. G. Jones, 1965, Pressure drawdown analysis, variable-rate case, in Pressure Analysis Methods: Dallas, TX, American Institute of Mining, Metallurgical and Petroleum Engineers, Society of Petroleum Engineers Reprint Series No. 9, 256 p.</ref> For gas wells, the data are plotted as

:<math>\frac{\bar{p}^{2} - p_{\rm wfn}^{2}}{q_{n}} \mbox{ versus } \frac{1}{q_{n}} \sum\limits_{j=0}^{n-1} \Delta q_{j} \log (t_{n} - t_{j})</math>

:<math>\frac{\bar{p}^{2} - p_{\rm wfn}^{2}}{q_{n}} \mbox{ versus } \frac{1}{q_{n}} \sum\limits_{j=0}^{n-1} \Delta q_{j} \log (t_{n} - t_{j})</math>