Well conditions at which the annulus pressure is building up after bleed-off.
This is normal behaviour if the annulus is connected to tubing by completion design (through the tubing shoe or an open valve).
In case the annulus has a packer installed then SAP indicates that there is a breach in the packer or the inner/outer pipes of the annulus leading to a fluid leakage.
Important Notice
Important notice: not all the downhole fluid leaks expose themselves as Sustainable Annulus Pressure (SAP).
See Also
Petroleum Industry / Upstream / Petroleum Well / Well completion
[ Well & Reservoir Surveillance / Leak Detection]