Like most countries, Portugal requires tourist visa applicants to show that they have sufficient funds for their stay.
Exactly how much is needed depends on the itinerary, but the minimum given by the Portuguese embassy is:
The minimum amount required per day is the equivalent to €40.00 plus €75.00 per entry into the country.
For a 7 day visit, this is €355. At the time I looked this up on xe.com, that worked out to AED 1387.
Note that you may need more than this, depending on the specifics of your itinerary (e.g. this is not enough to stay in a 5 star hotel).
Your AED 15000 appears more than sufficient to pay for a very nice holiday.