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Drilling Engineering - PE 311 Laminar Flow in Pipes and Annuli Non-Newtonian Fluids. Frictional Pressure Drop in Pipes and Annuli. When attempting to quantify the pressure losses in side the drillstring and in the annulus it is worth considering the following matrix:.
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Drilling Engineering - PE 311 Laminar Flow in Pipes and Annuli Non-Newtonian Fluids
Frictional Pressure Drop in Pipes and Annuli When attempting to quantify the pressure losses in side the drillstring and in the annulus it is worth considering the following matrix:
Pipe Flow – Power Law Fluids Frictional pressure drop in field unit:
Annular Flow – Power Law Fluids Frictional pressure drop in field unit:
Pipe Flow – Bingham Fluids Frictional pressure drop in field unit:
Annular Flow – Bingham Fluids Frictional pressure drop in field unit:
Examples Example 1: A Cement slurry that has a flow-behavior index of 0.3 and a consistency index of 9400 eq cp is being pumped in an 8.097x4.5 in. annulus at a rate of 200 gal/min. Assuming the flow pattern is laminar, compute the frictional pressure loss per 1000 ft of annulus. Also estimate the shear rate at the pipe wall. Mean velocity: Frictional pressure loss: Shear rate at the pipe wall:
Examples • Example 2: • Calculate the velocity of a fluid flowing through a 5’’ 19.5 lbm/ft drillpipe with I.D. = 4.276’’ at 150 GPM. • Determine the pressure loss in the above situation if the fluid is a Bingham Plastic fluid with a plastic viscosity of 20 cp, a yield point of 15 lbf/100ft2 and density of 10 ppg. (1 lbf/100ft2 = 0.479 Pa) • Calulate the pressure loss in the above situation if the fluid was a power law fluid with the flow behavior index of 0.75 and a consistency index of 70 eq cp. (lbfxSn/100ft2 = 479 eq cp)
Examples • Solution: • Calculate the velocity of a fluid flowing through a 5’’ 19.5 lbm/ft drillpipe with I.D. = 4.276’’ at 150 GPM. • b. Determine the pressure loss in the above situation if the fluid is a Bingham Plastic fluid with a plastic viscosity of 20 cp, a yield point of 15 lbf/100ft2 and density of 10 ppg. • c. Calulate the pressure loss in the above situation if the fluid was a power law fluid with the flow behavior index of 0.75 and a consistency index of 70 eq cp.