The Automated Permeability Plugging Apparatus (APPA), Model 389AP operates similar to the PPA, providing accurate simulation and measurement of downhole filtration. The advantage of the APPA is
automatic temperature and pressure control.
This 5,000 psig rated APPA is useful for predicting a drilling fluid’s ability to form a semipermeable filter cake that seals off depleted or underpressure intervals and helps prevent differential sticking. This design makes it possible for users to study filtration at higher differential pressures.