Heat the olive oil in a large pot or Dutch oven over medium heat. Add the onions and saute for 5 minutes, until golden and tender. Add the garlic, cumin and oregano and stir for 1 minute until you can smell the garlic. Stir in the black beans, orange juice, orange zest, and chicken broth. Season with salt and pepper. Bring to a simmer, and cook, stirring occasionally for about 15 minutes until the flavor meld a bit.
Remove half of the bean mixture and puree in a food processor or blender. Return the pureed beans to the pot. Taste, and adjust seasonings as needed. If the soup seems too thick, you can add a bit more broth.