ECD Calculator
Calculate Equivalent Circulating Density from annular pressure losses
Input Parameters
Enter wellbore and circulation data
Why ECD Matters
- ECD > Frac Gradient = Lost circulation risk
- ECD < Pore Pressure = Kick risk
- Narrow MW window requires careful ECD management
- ECD increases with flow rate and mud properties
ECD Results
Enter parameters and click Calculate
Typical ECD Increases
Shallow wells (<5000 ft): 0.2 - 0.5 ppg
Medium wells (5000-12000 ft): 0.3 - 0.8 ppg
Deep wells (>12000 ft): 0.5 - 1.5 ppg
HPHT wells: 1.0 - 2.0+ ppg
Formula Reference
ECD from Annular Pressure Loss
ECD = MW + (APL / (0.052 x TVD))
Where:
ECD = Equivalent Circulating Density (ppg)
MW = Static mud weight (ppg)
APL = Annular Pressure Loss (psi)
TVD = True Vertical Depth (ft)
0.052 = Conversion constant
Bottom Hole Pressure (Circulating)
BHP_circ = 0.052 x ECD x TVD
Or: BHP_circ = P_hydrostatic + APL
Annular Pressure Loss (Bingham Plastic)
APL = (PV x L x V) / (1000 x (Dh - Dp)^2) + (YP x L) / (200 x (Dh - Dp))
Where:
PV = Plastic Viscosity (cP)
YP = Yield Point (lb/100ft2)
L = Length (ft)
V = Annular velocity (ft/min)
Dh = Hole/Casing ID (in)
Dp = Pipe OD (in)
Annular Velocity
V = (24.5 x Q) / (Dh^2 - Dp^2)
Where:
V = Velocity (ft/min)
Q = Flow rate (gpm)