Gas-Lift Valve Opening Casing Pressure Formula
Gas-Lift Valve Opening Casing Pressure calculates injection or casing pressure at valve depth for well performance workflows in production engineering.
How engineers use this formula
Use this formula when the listed inputs (P_bt, P_2, A_p, A_b) 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, P_1 equals 1,300 psi.
1200
800
0.2
1
Inputs
P_bt
psiBellows or Dome Pressure at Valve Depth
P_2
psiProduction or Tubing Pressure at Valve Depth
A_p
in2Area of Valve Port or Seat
A_b
in2Area of Bellows
Outputs
P_1
Injection or Casing Pressure at Valve Depth
P_bt
Bellows or Dome Pressure at Valve Depth
P_2
Production or Tubing Pressure at Valve Depth
A_p
Area of Valve Port or Seat
A_b
Area of Bellows
Source and review
reviewedBeggs, H.D. 2003. Production Optimization using Nodal Analysis, OGCI and Petroskills Publications, Second Edition, Chapter 5, Page 166.
Source