This will happen first at the shoe of the annulus because the pressure will naturally be higher with the weight of the column of brine.
The following example is for the 'B' annulus of a gas lifted well, filled with 1.2 sg brine from the shoe at 4070ftTVD (true vertical depth) to surface.
1.2 sg brine produces a pressure gradient of 0.52 psi.ft−1 (see Well kill for the mathematical basics of hydrostatic heads).
Therefore, the column of brine produces a pressure difference between top and bottom of 2116 psi.
Collapse of the 9+5⁄8 in (240 mm) casing is clearly the limiting factor so the MAASP will be published as 2634 psi.