Drain beans, reserving cooking liquid. Discard rosemary sprig and bay leaf. Heat remaining 2 tablespoons oil in heavy large pot over medium heat. Add onion, carrot, and celery. Sprinkle with salt and pepper. Sauté until vegetables are beginning to soften, about 10 minutes. Add chopped garlic and 1 teaspoon thyme; sauté 2 minutes. Add 2 cups reserved bean cooking liquid, 4 cups chicken broth, and beans. Bring to boil; reduce heat to medium and simmer uncovered until vegetables are tender, about 25 minutes. Cool soup 10 minutes. Meanwhile, sauté chorizo in heavy large skillet over medium-high heat until cooked through, breaking up lumps with back of spoon, about 5 minutes. Transfer chorizo to paper towels to drain.