Fluid Loss Test and Porosity Plugging Test
The amount of fluid lost from a cement slurry can give an indication of certain properties such as settling, poor slurry design, spurt loss, and porosity plugging. The fluid loss apparatus enables the collection of a fluid filtrate over time as a slurry is heated and pressurized to simulate well conditions and allowed to flow, if possible, through a porous media that is intended to mimic the reservoir. This media is typically a 325-mesh screen for the Fluid Loss test or a ceramic disk for a Porosity Plugging Test. Two types of apparatus may be employed for a fluid loss test: A stirred fluid loss tester (left) in which the fluid is first conditioned within the apparatus itself, or a static fluid loss tester (right) in which the fluid is conditioned in a separate piece of equipment then transferred into the apparatus for the test. The static fluid loss tester is also known as a filter press, which can be modified for use in the porosity plugging test.