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Reservoir EngineeringWell Performance

Laminar Gas Flow Rate from Real-Gas Pseudopressure Formula

Qg=kh(φrφwf)1422T[0.5ln(4A/(1.781CArw2))+S]Q_g=\frac{kh(\varphi_r-\varphi_{wf})}{1422T[0.5\ln(4A/(1.781C_Ar_w^2))+S]}

Laminar Gas Flow Rate from Real-Gas Pseudopressure calculates gas flow rate for well performance workflows in reservoir engineering.

Calculate

How engineers use this formula

Use this formula when the listed inputs (k, h, phi_r, phi_wf, T, A, C_A, r_w, S) 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.

Default example

Using the default inputs, Q_g equals 56,547.157551 MSCF/day.

kmD

50

hft

40

phi_rpsi^2/cP

900000000

phi_wfpsi^2/cP

600000000

TdegR

600

Aft^2

4356000

C_Adimensionless

31.6

r_wft

0.328

Sdimensionless

5

Inputs

k

mD

Permeability

h

ft

Formation Thickness

phi_r

psi^2/cP

Average Reservoir Real-Gas Pseudopressure

phi_wf

psi^2/cP

Flowing Real-Gas Pseudopressure

T

degR

Reservoir Temperature

A

ft^2

Drainage Area

C_A

dimensionless

Shape Factor

r_w

ft

Wellbore Radius

S

dimensionless

Skin Factor

Outputs

Q_g

MSCF/day

Gas Flow Rate

phi_r

psi^2/cP

Average Reservoir Real-Gas Pseudopressure

phi_wf

psi^2/cP

Flowing Real-Gas Pseudopressure

k

mD

Permeability

h

ft

Formation Thickness

Source and review

reviewed

Advanced Reservoir Engineering, Ahmed, T., McKinney, P. D. (2005)

Ahmed, T. and McKinney, P. D. 2005. Advanced Reservoir Engineering, Gulf Publishing of Elsevier, Chapter 3, Page 188.

Source

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