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Transmissibility Between Tight Gas Compartments Formula

γ=γaγb(L1+L2)γaL2+L1γb\gamma=\frac{\gamma_a \gamma_b (L_1+L_2)}{\gamma_a L_2+L_1 \gamma_b}

Transmissibility Between Tight Gas Compartments calculates transmissibility between compartments for unconventional reservoirs workflows in reservoir engineering.

Calculate

How engineers use this formula

Use this formula when the listed inputs (gamma_a, gamma_b, L_1, L_2) are known and the assumptions behind the cited unconventional reservoirs 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, gamma equals 375 mD*ft^2/cP.

gamma_amD*ft^2/cP

600

gamma_bmD*ft^2/cP

300

L_1ft

100

L_2ft

150

Inputs

gamma_a

mD*ft^2/cP

Transmissibility of compartment 1

gamma_b

mD*ft^2/cP

Transmissibility of compartment 2

L_1

ft

Length of compartment 1

L_2

ft

Length of compartment 2

Outputs

gamma

mD*ft^2/cP

Transmissibility between compartments

gamma_a

mD*ft^2/cP

Transmissibility of compartment 1

gamma_b

mD*ft^2/cP

Transmissibility of compartment 2

L_1

ft

Length of compartment 1

L_2

ft

Length of compartment 2

Source and review

reviewed

Ahmed, T. and McKinney, P. D. 2015. Advanced Reservoir Engineering, Gulf Publishing Elsevier, Chapter 3, Page 236.

Source

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