Patent ID: 8635902

Claim:
A method of characterizing sag performance by determining a maximum particle size of a solid component that is capable of being suspended in a fluid portion of a fluid mixture, comprising: placing the fluid mixture in a test container having a lower portion and a higher portion; wherein a suction port and a return port are placed at the lower portion of the test container for directing the fluid mixture to a circulation loop including a density transducer; wherein the fluid mixture comprises a test section corresponding to the higher portion of the test container and a mixed section corresponding to the lower portion of the test container; determining a first density of the fluid mixture in the mixed section at a first point in time using the density transducer; inferring a first volume fraction of the solid component of the fluid mixture in the mixed section at the first point in time; determining a second density of the fluid mixture in the mixed section at a second point in time using the density transducer; inferring a second volume fraction of the solid component of the fluid mixture in the mixed section at the second point in time; determining a difference between the second volume fraction and the first volume fraction; determining an increase in mass of the solid component of the fluid mixture in the mixed section using the difference between the second volume fraction and the first volume fraction; and using a particle size distribution of the solid component and the increase in mass of the solid component in the fluid mixture in the mixed section to determine the particle size range of the solid component that is capable of being suspended in the fluid portion.