Yes you can. The process is long and requires a lot of documentation. It is called MODEL 3. DECLARATION FOR THE ACQUISITION OF PORTUGUESE NATIONALITY. art. 3 of the Nationality Law 37/81, 3/10. Documentation of all countries where one has lived since the age of 16 and the individual's country of birth is required. Some documents are only valid for 90 days and others for 6 months. Everything has to be certified / or, Apostilado. There can be no mistakes and the process is a little expensive. Coordinate everything well so that everything is valid for 90 days and be delivered to the Lisbon Central Registries.
Definitely you are entitled, last time I know is 5 years married
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