L1B experience in US on perdiem can counted as US experience?

In Oracle company, I have worked for 1 exact year with L1B visa, it does not transfer employe or give US salary, but make to work for them with expenses or perdiem.

Can this be claimed as experience in US along with 2.5 years current H1B experience ?

If it was a full time job and you have all the required documentation from your company to show your experience with them, it could be considered. I don’t think Canadian immigration is concerned about which visa you worked on, in another country.