Free Fluid Test

Free fluid is a measurement of the clear or colored fluid that comes to the top of a column of fluid after a static period (generally two hours), which may occur at ambient or heated conditions.  The fluid is removed by a syringe and measured to a precision of 0.2 ml.  This free fluid is expressed as a percentage of the original volume.

The cylinder may be vertical (0°) or angled (≤45°), and the setting for the static test period can be one of three methods: heated (≥ 190°F), heated (≤ 190°F), or ambient (~73°F).  In the first method, a pre-heated curing chamber or consistometer is used to heat the uncovered, fluid-filled cylinder for the static period, which includes the simulated time it takes the well to get from 190°F to test temperature as well as the time it takes to cool the vessel to 190°F for safe removal.  Slight pressure is applied in this method, to prevent boiling of the slurry.  In the second method, a pre-heated water bath is employed to heat the covered cylinder that is immersed to a water level above the slurry level.  In the third method, the cylinder is covered and set aside on a vibration-free spot in the lab for the static period. This 3^rd method is the method most commonly used by OTC, except as directed otherwise and noted in the table below.