Drilling EngineeringWell Control
Actual Gas Migration Rate from Casing Pressure Increase Formula
Actual Gas Migration Rate from Casing Pressure Increase calculates actual gas migration rate for well control workflows in drilling engineering.
How engineers use this formula
Use this formula when the listed inputs (P_csg_1, P_csg_2, dt_hr, MW) are known and the assumptions behind the cited well control 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, RGM equals 615.384615 ft/hr.
P_csg_1psi
450
P_csg_2psi
650
dt_hrhr
0.5
MWppg
12.5
Inputs
P_csg_1
psiInitial Shut-In Casing Pressure
P_csg_2
psiLater Shut-In Casing Pressure
dt_hr
hrElapsed Shut-In Time
MW
ppgMud Weight
Outputs
RGM
ft/hr
Actual Gas Migration Rate
P_inc_rate
intermediatepsi/hr
Casing Pressure Increase Rate
MWG
intermediatepsi/ft
Mud Pressure Gradient
P_csg_2
psi
Later Shut-In Casing Pressure
dt_hr
hr
Elapsed Shut-In Time
Source and review
reviewedDrillingFormulas.com actual gas migration rate; Drilling Manual gas percolation rate well-control example.
Source