Kill Weight Mud Determination - Moore Equation Calculator
Enter original mud weight, shut-in drillpipe pressure, and true vertical depth. The calculator returns the estimated kill mud weight.
Calculation context and source notes
Kill weight mud determination estimates the mud density required to balance formation pressure after a kick using original mud weight, shut-in drillpipe pressure, and true vertical depth.
Use it as a well-control arithmetic check when shut-in pressure has stabilized and the approved procedure calls for a kill mud weight calculation.
Solves for
KWM (ppg)
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Formula, variables, and sourceRelated source-backed guides
Formula, variables, and default calculation
Reproducible default result
With the default values shown below, the calculation returns KWM = 12.961538 ppg. Defaults demonstrate the implementation; they are not recommended field values.
500
12
10000
Input definitions
SIDPP
psiShut-In Drill Pipe Pressure
OMW
ppgOriginal Mud Weight
TVD
ftTrue Vertical Depth
Output definitions
KWM
Kill Weight Mud
SIDPP
Shut-In Drill Pipe Pressure
OMW
Original Mud Weight
TVD
True Vertical Depth
Engineering use, assumptions, and limits
Use it as a well-control arithmetic check when shut-in pressure has stabilized and the approved procedure calls for a kill mud weight calculation.
Assumptions
- Shut-in drillpipe pressure is stabilized and representative of formation overbalance needed.
- True vertical depth is used for the pressure-gradient conversion.
- The calculation follows the field-unit relationship used by the source equation.
Limitations
- Does not replace a complete kill sheet, choke schedule, or well-control method.
- Does not account for gas migration, subsea choke-line friction, changing hydraulics, or operational safety factors.
Common mistakes
- Using shut-in casing pressure where shut-in drillpipe pressure is required.
- Using measured depth instead of true vertical depth.
- Treating the computed mud weight as approved without checking company and regulatory well-control requirements.
Source and record status
Source metadata identifies the relationship implemented by the calculator. Check the cited edition, unit basis, and scope against the engineering case before operational use.
Lapeyrouse, N.J. 2002. Formulas and Calculations for Drilling, Production and Workover, 2nd Edition, Page 131.
Open source reference