Common Bluet

Thanks taka.ita, I guess you're right. But I'm lacking a damselfly guide to fully id them so I'll just keep looking.

If you look at the photo you'll see that the female is quite different from the male in terms of pattern on the abdomen. The male has small dark rings in the blue, the female has torpedo-like figures.

One very important lesson when id-ing dragonflies/damselflies is that the pattern is much more important than the color. In fact most species can be identified from black-and-white photos.

Mary, when I said I didn't think it was an Enallagma, I was referring to E. cyathigerum which Madalena suggested, so I apologize.
To be honest, I know nothing about damselflies, I was just "excluding" the other hypothesis because apparently E. cyathigerum has a really marked sexual dimorphism, which these specimens don't have.

May I ask you why do you think it's a Circumpolar Bluet?

By the way, thanks for the help!

Honestly, I think it is a Circumpolar Bluet ,Enallagma cyanigerum, but if you don't think it's a Enallagma,I don't know what to say.

Thanks for the ID Madalena but I don't think it's an Enallagma. That species apparently have huge sexual dimorphism, with the female being brown. This one is seemingly blue, I mean both look very similar.
I looked up other possible genus that occur in Portugal and put them in the description. Maybe someone else will be able to help..