In large saucepan or Dutch oven, heat oil over medium heat. Add onions, peppers and garlic; sauté until onions are softened (about 3-5 minutes).
Add soaked beans, chicken broth, 1-2 tablespoons Creole seasoning, thyme and cayenne pepper. Bring to a boil; reduce heat and simmer, partially covered, until beans are tender and creamy (about 2 hours).
Season shrimp with remaining 1 tablespoon Creole seasoning; add to beans and continue cooking until shrimp is opaque and cooked through (about 10 minutes).