Thickening Time Test

A Thickening Time test is used to simulate pumping conditions in order to determine a length of time before the cement becomes difficult or impossible to pump.  The most common method to determine Thickening Time is via a pressurized consistometer. This device allows high pressures and temperatures to be applied to a cement slurry while it is being stirred (typically at 150 rpm).  A resistor arm on a potentiometer indicates resistance to the paddle turning as the cement sets.  The apparatus is calibrated to a standard output in Bearden Consistency units, “Bc,” which is a scale from 1 to 100 where, generally, difficult pumping is thought to begin at 50 Bc with a complete set at 100 Bc. The device is fully automated and can simulate squeeze schedules and/or batch mixing, etc.  OTC’s consistometers have also been retrofitted with variable speed motors for use in the dynamic settling test (described below).