In IPR curves, Pwf denotes what?

• A. Bottom-hole pressure
• B. Reservoir pressure
• C. Pore pressure
• D. Wellhead pressure

Answer: (A)

In IPR curves, the pressure at the bottom of the well when fluids are flowing is the driving pressure for production. This bottom-hole flowing pressure represents the pressure right at the end of the tubing where the reservoir fluids first enter the wellbore, including the effects of hydrostatic head and friction losses along the tubing. The IPR curve relates how much fluid can be produced to this bottom-hole pressure, showing how the reservoir can deliver fluids under the pressure available at the well’s bottom. This is different from reservoir or pore pressure, which describe pressures within the rock formation itself, and from wellhead pressure, which is the pressure measured at the surface.