... 0.433 pdft = 0.433 2 Formulas and Calculations Metric calculations Pressure gradient, barlm = drilling fluid density kg/l x 0.0981 Pressure gradient,bar/lOm = drilling fluid density ... of stands x length per x displacement stand, ft bbVft displaced pulled Step 2 HP,psi - mud barrels displaced o.052 weight, PPg - bbVft bbVft Formulas Calculations for Drilling, ... Calculations for Drilling, Production, Workover and and Second Edition Basic Formulas 21 Example: Determine the hydrostatic pressure decrease when pulling DRY Number of stands pulled = 5...