Rinse beans, and then soak in a large pot of water overnight.
In a skillet, heat oil over medium heat. Cook onion, bell pepper, garlic, and celery in olive oil for 3 to 4 minutes.
Rinse beans, and transfer to a large pot with 7 cups water. Stir cooked vegetables into beans. Season with bay leaves, cayenne pepper, thyme, sage, parsley, chicken base and Cajun seasoning. Bring to a boil, and then reduce heat to medium-low. Simmer for 2 1/2 hours.
Mash some of the beans to make the liquid creamy.
Stir sausage and salt into beans, and continue to simmer for 30 minutes.
Meanwhile, prepare the rice. In a saucepan, bring water and rice to a boil. Reduce
heat, cover, and simmer for 20 minutes. Serve beans over steamed rice.