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Reservoir EngineeringThermal Gradients

Average Temperature of a Gas Column Formula

T=Tt+Tb2T = \frac{T_t + T_b}{2}

Average Temperature of a Gas Column calculates arithmetic average temperature for thermal gradients workflows in reservoir engineering.

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How engineers use this formula

Use this formula when the listed inputs (T_t, T_b) 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 equals 570 °R.

T_t°R

520

T_b°R

620

Inputs

T_t

°R

Tubing Head Temperature

T_b

°R

Wellbore Temperature

Outputs

T

°R

Arithmetic Average Temperature

T_t

°R

Tubing Head Temperature (rearranged)

T_b

°R

Wellbore Temperature (rearranged)

Source and review

reviewed

Ahmed, T., McKinney, P.D. (2005). Advanced Reservoir Engineering, Gulf Publishing of Elsevier, Chapter: 3, Page: 199.

Source

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