Production EngineeringHydraulic Fracturing
Principal Stress Due to Petro-Static Pressure - Hydraulic Fracturing Formula
Principal Stress Due to Petro-Static Pressure - Hydraulic Fracturing calculates principal stress in z-axis for hydraulic fracturing workflows in production engineering.
How engineers use this formula
Use this formula when the listed inputs (gamma, h) are known and the assumptions behind the cited hydraulic fracturing 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, sigma_z equals 690 kp/cm^2.
gammap/cm^3
2.3
hm
3000
Inputs
gamma
p/cm^3Average Specific Weight of Formation
h
mDepth
Outputs
sigma_z
kp/cm^2
Principal Stress in z-axis
gamma
p/cm^3
Average Specific Weight of Formation
h
m
Depth
Source and review
reviewedSaydam, T. 1967. Principles of Hydraulic Fracturing, ARI Publishing Co., Page 5.
Source