MInPet (Luanda)

When you work for a Large IOC company on assignment to Angola- How long does it take before MinPet approvals for a work permit take.
I do know the saying TIA- This is Africa but I want to believe that Angola must be better than Nigeria.
At some stage all Expats would have had to deal with this issue- so some feedback would be welcomed.
Lyndon Berchy
Sweden