Who is equivalent to oceanus in Norse mythology?

If you mean the God or Gods of the Ocean ... there is 3 I suppose. Njord is the Vanic God of the bounty of the ocean, the fruit of the waters. He's a fisherman, lives on a boat, and is generally a good natured God. There is then the Jotuns, Aegir and Ran. Aegir is a Jotun (Giant) of the Ocean, who is the raw chaotic force of the waves. He lives underwater with his wife Ran, who has a net used to drag sailors to their deaths. In Aegir's hall, gold was used as fire to light his hall, and so Ocean's fire, or Aegir's fire, can be used as a poetic kenning for gold.