Craft and Hawkins Vertical Well Critical Coning Rate Calculator
Enter the required inputs, confirm the units, and run the calculator to solve q_o. Review the formula source and assumptions before using the result in engineering work.
Calculation context and source notes
Craft and Hawkins Vertical Well Critical Coning Rate calculates critical oil rate without coning for well performance workflows in reservoir engineering. The page keeps the declared variables, units, source relationship, and output definition visible for technical review.
Use this formula when the listed inputs (b, r_w, h, k_o, p_ws, p_wf, mu_o, B_o, r_e) are known and the assumptions behind the cited well performance relationship match the engineering case being checked.
Solves for
q_o (STB/day)
Best next page
Formula, variables, and sourceFormula, variables, and default calculation
Reproducible default result
With the default values shown below, the calculation returns q_o = 643.734212 STB/day. Defaults demonstrate the implementation; they are not recommended field values.
0.5
0.328
50
100
3000
2500
2
1.2
1000
Input definitions
b
dimensionlessPenetration Ratio, h_p / h
r_w
ftWellbore Radius
h
ftOil Column Thickness
k_o
mDEffective Oil Permeability
p_ws
psiStatic Well Pressure at Producing Interval Midpoint
p_wf
psiFlowing Well Pressure at Producing Interval Midpoint
mu_o
cPOil Viscosity
B_o
RB/STBOil Formation Volume Factor
r_e
ftDrainage Radius
Output definitions
q_o
Critical Oil Rate without Coning
PR
Productivity Ratio
k_o
Effective Oil Permeability
p_ws
Static Well Pressure at Producing Interval Midpoint
p_wf
Flowing Well Pressure at Producing Interval Midpoint
Engineering use, assumptions, and limits
Use this formula when the listed inputs (b, r_w, h, k_o, p_ws, p_wf, mu_o, B_o, r_e) 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.
Frequently asked questions
What inputs does the Craft and Hawkins Vertical Well Critical Coning Rate calculator need?
The calculation uses Penetration Ratio, h_p / h (b), Wellbore Radius (r_w), Oil Column Thickness (h), Effective Oil Permeability (k_o), Static Well Pressure at Producing Interval Midpoint (p_ws), Flowing Well Pressure at Producing Interval Midpoint (p_wf), Oil Viscosity (mu_o), Oil Formation Volume Factor (B_o), Drainage Radius (r_e). Enter values on the units shown beside each field.
What result does this calculator return?
The primary result is critical oil rate without coning in STB/day. The formula section shows the declared relationship, variables, and a reproducible default calculation.
What should I check before using the result?
Confirm the unit basis, source applicability, and input quality. The calculation does not replace a full engineering model or operating procedure. Mixing unit systems without converting the inputs.
Source and record status
Source metadata identifies the relationship implemented by the calculator. Check the cited edition, unit basis, and scope against the engineering case before operational use.
Joshi, S.D. 1991. Horizontal Well Technology, Chapter 8, vertical-well critical-rate correlations.
Open source reference