Reservoir EngineeringThermal Gradients
Formation Temperature for a Given Gradient Formula
Formation Temperature for a Given Gradient calculates formation temperature for thermal gradients workflows in reservoir engineering.
How engineers use this formula
Use this formula when the listed inputs (T_s, D, g_G) are known and the assumptions behind the cited thermal gradients 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, T_f equals 203 °F.
T_s°F
75
Dft
8000
g_G°F/100ft
1.6
Inputs
T_s
°FTemperature Near Surface
D
ftTotal Depth
g_G
°F/100ftGeothermal Gradient
Outputs
T_f
°F
Formation Temperature
T_s
°F
Surface Temperature (rearranged)
D
ft
Total Depth (rearranged)
g_G
°F/100ft
Geothermal Gradient (rearranged)
Source and review
reviewedBassiouni, Z. (1994). Theory, Measurement, and Interpretation of Well Logs. SPE Textbook Series Vol. 4, Chapter 4, Page 75.
Source