oil_rate_linear
Calculate oil production rate for horizontal wells or linear flow geometries using Darcy's law with automated PVT property computation.
Instructions
Calculate oil production rate for linear flow.
INFLOW PERFORMANCE TOOL - Computes oil production rate for horizontal wells or wells with linear flow geometry using Darcy's law. Automatically calculates PVT properties (Rs, Bo, μo) at average pressure. Essential for horizontal well performance analysis and completion design.
Parameters:
pi (float, required): Initial/reservoir pressure in psia. Must be > 0. Example: 4000.0.
pb (float, required): Bubble point pressure in psia. Must be ≥ 0. Example: 3500.0. If pi < pb, reservoir is saturated (gas cap present).
api (float, required): Oil API gravity in degrees. Valid: 0-100. Example: 35.0.
degf (float, required): Reservoir temperature in °F. Valid: -460 to 1000. Example: 180.0.
sg_g (float, required): Gas specific gravity (air=1). Valid: 0-3. Typical: 0.6-1.2. Example: 0.75.
psd (float or list, required): Sandface/draining pressure(s) in psia. Must be > 0 and < pi. Can be scalar or array. Example: 1500.0 or [1000, 1500, 2000].
h (float, required): Net pay thickness in feet. Must be > 0. Typical: 10-200 ft. Example: 50.0.
k (float, required): Permeability in millidarcies (mD). Must be > 0. Typical: 1-1000 mD. Example: 100.0.
area (float, required): Cross-sectional flow area in square feet. Must be > 0. Typical: 100-10000 ft². Example: 1000.0.
length (float, required): Flow length in feet. Must be > 0. Typical: 100-5000 ft. Example: 500.0.
rsb (float, required): Solution GOR at bubble point in scf/stb. Must be ≥ 0. Example: 800.0.
Flow Geometry: Linear flow occurs in:
Horizontal wells (early-time flow)
Hydraulically fractured vertical wells (fracture flow)
Channelized reservoirs
Edge water drive systems
Darcy's Law Formula (Linear): qo = (0.001127 × k × area × (pi - pwf)) / (μo × Bo × length)
Where PVT properties (μo, Bo) are calculated at average pressure (pi + pwf)/2.
Linear vs Radial Flow:
Linear: Flow perpendicular to wellbore (horizontal wells)
Radial: Flow converging to wellbore (vertical wells)
Linear flow typically has higher productivity than radial
Returns: Dictionary with:
value (float or list): Oil rate in STB/day (matches input psd shape)
method (str): "Darcy linear flow"
units (str): "STB/day"
inputs (dict): Echo of input parameters
Common Mistakes:
Using separator temperature instead of reservoir temperature
Pressure in barg/psig instead of psia (must be absolute)
Confusing flow area (perpendicular to flow) with wellbore area
Using wrong flow length (should be distance from boundary to well)
Not accounting for net pay thickness correctly
Confusing linear flow (horizontal wells) with radial flow (vertical wells)
Example Usage:
{
"pi": 4000.0,
"pb": 3500.0,
"api": 35.0,
"degf": 180.0,
"sg_g": 0.75,
"psd": [1500, 2000, 2500],
"h": 50.0,
"k": 100.0,
"area": 1000.0,
"length": 500.0,
"rsb": 800.0
}Result: Oil rate decreases as sandface pressure increases (typical IPR curve).
Note: This tool automatically calculates PVT properties. You don't need to provide Rs, Bo, or μo - they are computed internally at average pressure. Linear flow is characteristic of horizontal wells and hydraulically fractured wells.
Input Schema
| Name | Required | Description | Default |
|---|---|---|---|
| request | Yes |
Output Schema
| Name | Required | Description | Default |
|---|---|---|---|
No arguments | |||