Sustained Casing Pressure (SCP)
Pressure in an annulus of non-structural casing strings that is: 1. measurable at the wellhead of a casing annulus that rebuilds to at least the same pressure level when bled down; 2. not caused solely by temperature fluctuations; and 3. not a pressure that has been imposed by the operator.
Source: API RP 90, Annular Casing Pressure Management for Offshore Wells, Upstream Segment. First Edition, August 2006. Global Standards