By adding bbl of base fluid required, dilution of mud can help control Low Gravity Solid (LGS) in mud system. This post will demonstrate you how to determine barrels of dilution fluid such as water or base fluid required to achieve the desired low gravity solid.
Formula used to calculate dilution of mud system is listed below;
Vwm = Vm x (Fct – Fcop) ÷ (Fcop)
Where; Vwm = barrels of dilution water or base fluid needed
Vm = total barrels of mud in circulating system
Fct = percent low gravity solids in system
Fcop = percent total low gravity solids desired
Example: Determine how much barrels of base oil to dilute total 2000 bbl of mud in system from total LGS = 7 % to desired LGS of 3.5 %.
Vm = 2000 bbl
Fct = 7%
Fcop = 3.5%
Vwm = 2000 x (7 – 3.5) ÷ 3.5
Vwm = 2000 bbl
In order to dilute total of 2000 bbl of the original mud with 7% LGS down to 3.5% LGS, 2000 bbl of base oil is required to add into the system.
Ref book: Formulas and Calculations for Drilling, Production and Workover, Second Edition