In a medium saucepan, heat the olive oil until shimmering. Add the onion and cook over moderate heat, stirring occasionally until softened, about 3 minutes. Add the garlic along with the chipotle, cumin and oregano and cook, stirring, until fragrant, 2 minutes. Add the black beans and chicken stock and simmer, partially covered, for 15 minutes. Using a potato masher, coarsely crush some of the beans.
Meanwhile, heat a large skillet over high heat. Add the sausage and cook until browned, stirring occasionally, about 5 minutes. Add the sausage to the beans, along with the lime juice and cilantro; season with salt and pepper. Simmer the soup for 2 minutes to allow the flavors to blend. Ladle the soup into bowls and serve, passing the sour cream and lime wedges separately.