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This part of well control formulas will demonstrate you more about some equations frequently used in snubbing operation. In Well Control Formulas Part 5, I show just only some snubbing formulas and this part will show the rest of them.

I wish you would enjoy reading my blog post.

Buoyed Weight of Open Ended Tubulars (Wb),lb

For this formula, you just use the buoyancy factor and multiply it with weight of pipe in the air.

Buoyed Weight of Closed Ended Tubulars without fluid in the pipe (Wb),lb

This formula below is different from the 1st formula because it is used for the closed ended pipe. Weight in the air will be subtracted with buoyancy weight of pipe ran in hole.

Note: 24.5 is conversion factor to make the unit in gallon.

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This part of well control formula series (part#5) will show you following equations: mud increment for volumetric, lube increment for lubricate and bleed, bottle capacity required for koomey unit, volume of usable fluid,  and snubbing force for snubbing operation. Later on, I will show you how to apply equations to particular situation. Anyway this is part 5 and total will be 8 parts.

Mud Increment for Volumetric Method (MI), bbl

Lube Increment for Lubricate and Bleed Method (LI), bbl

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I added some formulas that you must use in the event of well control situation.  Well control formulas part 4 consists of Height of Influx, rate of gas migration, Barite Requirement For Weight-up ,Volume Gain From Slug, Triplex Pump Output, Pump Output, Pump Pressure With New Pump Strokes, and Boyle’s Law

I will keep updating good well control formulas for you. I wish you would enjoy learning about well control formulas.

Height of Influx, ft

Approximate gas migration rate, ft/hr

Sacks of Barite Required For Weight-up, sx

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This is the 3rd part of well control formulas.

Annulus Capacity Factor (ACF),bbl/ft

Final Circulating Pressure (FCP), psi

Surface To Bit Strokes, strokes

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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