Facilities Sand Management: Calculations - Concentration (B-FSM022)
Articles B-FSM-10 through B-FSM-20 covered sampling and properties of produced solids. Through this we generate a substantial amount of data and information. The next several articles will cover “What to do with the solids analysis data”.
Four main areas will be detailed by showing calculations and conversions for;
- Concentration of solids in a fluid stream (demystify all the myriad concentration terms – e.g. ppmw, ppmv, pptb, mg/l, kg/d, volume or weight percent, etc.)
- Density and packing void fraction (as applies to slurry density, apparent and bulk density, and packing of solids settled in a vessel)
- Particle settling rate (Where is Stokes’ Law valid?)
- Oil-on-solids content and concentration (or “How does adsorbed oil layer affect particle density?”
Concentration of Solids in a Fluid Stream
These calculations start with the base assumption that all solids are in the liquid phase (even when in a multiphase stream).
Appropriate terms for solids concentration are;
- Concentration by volume: volume fraction, volume percent, and parts per million by volume (ppmv)
- Concentration by weight: weight fraction, weight percent, and parts per million by weight (ppmw)
Colloquial terms that are to be converted to Concentration terms are;
- Solids production rate: kg/d or lb/d
- Solids weight per volume: pounds per thousand barrels (pptb) or mg/l
Concentration by Volume and Weight, and Conversion Between Them
Converting from Solids Production Rate
Converting from Solids Weight per Volume
The next article will cover calculations for density and volume fraction solids.