Joshi Horizontal Well Critical Rate for Gas Coning Formula
Joshi Horizontal Well Critical Rate for Gas Coning calculates critical oil rate for well performance workflows in reservoir engineering.
How engineers use this formula
Use this formula when the listed inputs (rho_o, rho_g, r_e, r_w, l_v, h, mu_o, B_o, k_h) are known and the assumptions behind the cited well performance relationship match the engineering case being checked.
Assumptions
- Input values are representative for the well, reservoir, fluid, or equipment case being evaluated.
- The declared units match the field-unit constants used in the formula.
- The cited formula applies to the selected petroleum engineering workflow.
Limitations
- The calculation does not replace a full engineering model or operating procedure.
- Accuracy depends on the source correlation, assumptions, input quality, and unit consistency.
Common mistakes
- Mixing unit systems without converting the inputs.
- Using default example values as field recommendations.
- Applying the formula outside the source assumptions.
Default example
Using the default inputs, q_o equals 9.566847 STB/day.
0.85
0.1
1000
0.328
20
50
2
1.2
100
Inputs
rho_o
g/ccOil Density
rho_g
g/ccGas Density
r_e
ftEffective Drainage Radius
r_w
ftWellbore Radius
l_v
ftDistance Between Gas-Oil Interface and Perforated Top of Vertical Well
h
ftOil Column Thickness
mu_o
cPOil Viscosity
B_o
RB/STBOil Formation Volume Factor
k_h
mDHorizontal Permeability
Outputs
q_o
Critical Oil Rate
k_h
Horizontal Permeability
mu_o
Oil Viscosity
B_o
Oil Formation Volume Factor
Source and review
reviewedJoshi, S.D. 1991. Horizontal Well Technology, gas-coning critical-rate method, pages 286-295.
Source