ECD Drill-Out Planner

Operational Inputs

Tubing OD, in Casing ID, in Current Flow Rate, bpm Funnel Viscosity for Quick Re, sec/qt Mud Weight, ppg Bit Depth (MD), ft Total Depth (TD), ft TVD, ft Estimated Pore Pressure, psi/ft Estimated Frac Pressure, psi/ft

Quick Reynolds Check

Reynolds Number-

Flow State-

Frac Gradient Import

Upload a Loader workbook to auto-map stage depth + frac gradient.

Workbook (.xlsm/.xlsx)

No file imported. Using manual frac gradient input.

Detected rows:

Stage	Depth (MD ft)	Frac Grad (psi/ft)

ECD Information Note

Equivalent Circulating Density (ECD) is the effective mud weight at the bottom of the well while circulating, which includes both the static mud weight and the additional pressure caused by annular friction. It represents the bottomhole pressure expressed as an equivalent fluid density (ppg).

Formulas used in this app:

AV (ft/min) = (1029 * Q_bpm) / (CasingID^2 - WorkstringOD^2)
APL (psi) = (1.4327e-7 * MW_ppg * MD_ft * AV^2) / (CasingID - WorkstringOD)
ECD (ppg) = MW_ppg + APL / (0.052 * TVD_ft)
Pore Gradient (ppg) = PorePressure(psi/ft) / 0.052
Frac Gradient (ppg) = FracPressure(psi/ft) / 0.052 (or imported by depth profile)
Q_gpm = 42 * Q_bpm (used in the Quick Reynolds check)
mu_app (cP) = (FV - 26) / 1.2
Re = (928 * MW * Q_gpm) / (mu_app * (Dh - Dp))

ECD vs Measured Depth

Simple model: current, ±0.5 bpm, max safe flow, pore limit, and frac limit.

Live Calculations at Bit Depth

Annular Velocity

Annular Pressure Loss

Current ECD

Pore Gradient

Frac Gradient

Max Safe Flow Rate