Welltest 106: Impulse & Closed Chamber Tests

Perforation Inflow Diagnostic (PID) Tests—Conventional Analysis. For this test, a surface #welltest data recorder was rigged in, the well was perforated, and the resulting pressure buildup was recorded. As per accepted closed-chamber #DST theory, gas inflow rates were calculated based on the change in pressure with time (Dp/Dt). This process can be simplified over a fixed time period (i.e. 5, 10, 30 minutes), or rigorously applied to each positive Dp increment, to generate an instantaneous gas (#LNG) AOF value. The #AOF back-pressure plot is nevertheless terminated at one-half (½) of the static reservoir pressure value, defined as the critical flow cut-off point.