These are some formulas used in well control operation. I will spit all content into several parts ^_^
Equivalent Circulating Density (ECD) , ppg
Equivalent Circulating Density (ECD) ,ppg = (annular pressure loss, psi) ÷ 0.052 ÷ true vertical depth (TVD), ft + (current mud weight, ppg)
Leak-off Test Equivalent Mud Weight (LOT), ppg
Leak off test (ppg) = (Leak off test pressure in psi) ÷ 0.052 ÷ (Casing Shoe TVD in ft) + (Mud Weight used for LOT in ppg)
Maximum Initial Shut-In Casing Pressure (MISICP), psi
This calculation is based on shoe fracture which is equal to Leak Off Test Pressure.
MISICP (psi) = [LOT (ppg) – Current Mud Weight (ppg)] x 0.052 x Shoe TVD (ft)
Kill Mud Weight to Balance Formation (KMW), ppg
KWM (ppg) = [Shut In Drill Pipe Pressure (SIDP), psi ÷ (0.052x True Vertical Depth (TVD) of the well, ft)] + Original Mud Weight (ppg)
Slow Circulation Rate (SCR), psi
SCR (psi) = Initial Circulating Pressure (psi) – Shut In Drill Pipe Pressure (psi)
Ref book: 
Formulas and Calculations for Drilling, Production and Workover, Second Edition
Well Control Books
