Drilling EngineeringWell Control
Time to MAASP During Gas Migration Formula
Time to MAASP During Gas Migration calculates time to reach maasp for well control workflows in drilling engineering.
How engineers use this formula
Use this formula when the listed inputs (MAASP, SICP_current, RGM, MWG) 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, t_limit equals 1.373626 hr.
MAASPpsi
1200
SICP_currentpsi
650
RGMft/hr
616
MWGpsi/ft
0.65
Inputs
MAASP
psiMaximum Allowable Annular Surface Pressure
SICP_current
psiCurrent Shut-In Casing Pressure
RGM
ft/hrGas Migration Rate
MWG
psi/ftMud Pressure Gradient
Outputs
t_limit
hr
Time to Reach MAASP
MAASP
psi
Maximum Allowable Annular Surface Pressure
SICP_current
psi
Current Shut-In Casing Pressure
Source and review
reviewedDrilling Manual MAASP and gas percolation well-control relationships.
Source