Physical Properties of Oil & Gas Particulate Solids - Density (B-FSM-013)
Particulate solids have three types of density that can be measured – bulk, apparent, and true. Each type provides specific information for design of a Facilities Sand Management system.
Bulk Density
The weight of the many particles divided by total volume
Depends on particle apparent density, particle size distribution, and degree of compaction or settling
Used to convert weight to volume of total solids handled and transported
Measured with bulk container – easy to measure in the field
Value dependent upon degree of compaction and fluid filling void space
The photo below shows field measurement (estimate) of collected solids using a glass container
Apparent Density
Density of individual particles inclusive of any closed pore space or cracks
Also includes density of clusters or aggregates that act as single particle
Measured with immersion pycnometer (Archimedes Principle)
Used to calculate movement of actual particle through fluid and calculation of bulk density (packing) from concentration
The photo below shows sand from a Texas oil well showing particle fractures
True Density
Density of base material (mineral) making up individual particles
The particles are ground/crushed to expose all particle pore space or cracks then measure with immersion pycnometer
Used to compare mineralogy of particle
Photo below shows immersion pycnometer measuring density of ground sand
All densities have the value of mass per unit volume. Common units are kg/m³, lb/ft³, or g/cm³. A comparison of densities for common minerals encountered in oil and gas industry are listed in the table below.
Bibliography
Lowell, S., Shields, J.E., Thomas, M.A., Thommes, M. Characterization of Porous Solids and Powders: Surface Area, Pore Size and Density – Particle Technology Series Book 16. 2006.