What Is the Petroleum Reservoir Radial Flow IPR Calculator?
Inflow Performance Relationship (IPR) defines the fluid delivery capacity of a porous reservoir into a wellbore.
How Does the Petroleum Reservoir Radial Flow IPR Calculator Work?
Drawdown between reservoir pressure and flowing BHP drives radial fluid flow through Darcy porous medium.
Petroleum Reservoir Radial Flow IPR Calculator Formula & Variables
The core mathematical equation utilized by this calculator is expressed as:
J = rac{0.00708 k h}{mu B_o left[ ln(r_e / r_w) - 0.75 + s
ight]}, quad q = J (P_r - P_{wf})
Pseudosteady-state Darcy radial flow equation in oilfield units.
How to Use the Petroleum Reservoir Radial Flow IPR Calculator
- Input rock permeability, pay zone thickness, fluid viscosity, FVF, drainage geometry, skin, and pressures.
Step-by-Step Example Calculation
Conventional Sandstone Producing Well
Input Values:
permeabilityMd:65
formationThicknessFt:35
viscosityCp:1.4
formationVolumeFactorB:1.25
drainageRadiusFt:1320
wellboreRadiusFt:0.354
skinFactor:2
reservoirPressurePsi:3200
flowingBhpPsi:2100
Worked Steps: Productivity index J = 0.985 STB/d/psi, production rate q = 1,083 STB/day, AOF = 3,151 STB/day.
Understanding Your Result
Provides productivity index J in STB/day/psi, operating production rate q, and theoretical maximum AOF.
Factors That Affect the Result
- Near-wellbore skin damage severely degrades productivity; hydraulic fracturing creates negative skin, boosting flow.
When Should You Use This Calculator?
- Nodal analysis, tubing string sizing, artificial lift design, and stimulation evaluation.
Assumptions & Limitations
- Applies to single-phase liquid flow above bubble-point pressure.
Frequently Asked Questions
Calculation Accuracy & Reference Note
Standard petroleum engineering Darcy radial flow equation.