flow after flow

1. n. [Production Testing]
A type of deliverability test conducted in gas wells to generate a stabilized gas deliverability curve (IPR). In a flow-after-flow test, a well flows under a constant rate until it reaches stabilized conditions (pseudosteady state). After the stabilized rate and pressure are recorded, the rate is changed and the well flows until pressure stabilizes again. The same procedure is repeated three or four times. The stabilization requirement is an important limitation of this type of test, especially in low-permeability formations, which require longer stabilization times. This test is also known as a backpressure or four-point test.