3. Drilling Fluids

Table of Content

1. Increase Mud Weight
2. Dilution
3. Mixing Fluids of Different Densities
4. Oil Based Mud Calculations
5. Solids Analysis
6. Solids Fractions
7. Dilution of Mud System
8. Displacement - Barrels of Water/Slurry Required
9. Evaluation of Hydrocyclone
10. Evaluation of Centrifuge

3.9 Evaluation of Hydrocyclone

Determine the mass of solids (for an unweighted mud) and the volume of water discarded by one cone of a hydrocyclone (desander or desilter):

Volume fraction of solids (SF):

$\text{SF}=\frac{\mathrm{MW}-8.33}{13.37}$
SF = 0.5737

Mass rate of solids (MS):

$\text{MS}=19.530\times \mathrm{SF}\times \frac{V}{T}$

Volume rate of water (WR)

$\text{WR}=900\times (1-\mathrm{SF})\times \frac{V}{T}$

where SF = fraction percentage of solids
MW = average density of discarded mud, ppg
MS = mass rate of solids removed by one cone of a hydrocyclone, lb/hr
V = volume of slurry sample collected, quarts
T = time to collect slurry sample, seconds
WR = volume of water ejected by one cone of a hydrocyclone, gal/hr

Example: Average weight of slurry sample collected = 16.0 ppg Sample collected in 45 seconds
Volume of slurry sample collected 2 quarts

Volume fraction of solids (SF):

$\text{SF}=\frac{16.0-8.33}{13.37}$
SF = 0.5737

Mass rate of solids (MS):

$\text{MS}=19.530\times 0.5737\times \frac{2}{45}$
MS = 11,204.36 × 0.0444
MS = 497.97 lb/hr

Volume rate of water (WR)

$\text{WR}=900\times (1-0.5737)\times \frac{2}{45}$
WR = 900 × 0.4263 × 0.0444
WR = 17.0 gal/hr

⬆ Table of Content