Boundary flow response behavior of Figure 3.
|Symbol description||Closed & infinite, r eD [Θ] & r eD [∞]||Const-pressure & infinite, r eD [Ω] & r eD [∞]|
|Response behavior||①Wellbore storage: unit slope||①Wellbore storage: unit slope|
|②Skin transition flow||②Skin transition flow|
|③IARF: const derivative 0.5||③IARF: const derivative 0.5|
|④CBF: unit slop||④CpBF: const slope (−2.5 is its limit)|
|⑤CpBF||⑤Pseudo-CpBF: const slope m = aκ[Ω]|
|⑥Pseudo-IARF: const derivative l = l 0/κ[∞]|
Where κ[∞] is the permeability ratio of infinite layer, l 0 is the pressure derivative value when the κ[Ω] = 1, a is the coefficient.
Notes: “IARF” is Infinite-Acting Radial Flow, “CBF” is Closed Boundary Flow, “CpBF” is the Const-Pressure Boundary flow.