It won’t help. And I think that’s their biggest fear.
Under dynamic conditions (i.e., flowing), the pressure upstream (below) the BOP is apparently ~3000 psi.
Under static conditions (no flow) the pressure under the BOP will increase to the formation pressure minus the 13000 ft static head of oil/gas mixture in the annulus.
The question is...will the 16” casing hold that pressure? The burst strength of the 16” casing is apparently ~10,000 psi.
What happens if it bursts?