Composite Inflow Performance Relationship
Composite IPR curve is determined geometrically from those equations considering the fractional flow of oil and water .
Math and Physics
Total flow rate equations:
For Pb < Pwf < Pr
For pressures between reservoir pressure and bubble point pressure:
For PwfG < Pwf < Pb
For pressures between the bubble point pressure and the flowing bottom-hole pressures:
For 0 < Pwf < PwfG
Composite IPR calculation example
Following the example problem #21, page 33 :
- = 2550 psi
- = 2100 psi
- = 2300 psi
- = 500 b/d
Determine the Composite IPR curves for Fw=0, 0.25, 0.5, 0.75, and 1.
The problem was run through PQplot software for different values of watercut.
Result Composite IPR curves are shown on Fig.1. Points indicate results obtained by Brown .
- = calculation variables
- = oil fraction, fraction
- = water fraction, fraction
- = productivity index, stb/d/psia
- = pressure, psia
- = flowing rate, stb/d
- b = at bubble point
- max = maximum
- o = oil
- r = reservoir
- t = total
- wf = well flowing bottomhole pressure
- wfG = well flowing bottomhole pressure at point G
- Brown, Kermit (1984). The Technology of Artificial Lift Methods. Volume 4. Production Optimization of Oil and Gas Wells by Nodal System Analysis. Tulsa, Oklahoma: PennWellBookss.