In a large skillet, heat the olive oil over medium heat. Add the onion, celery and bell pepper and cook, stirring often, until the onion is softened, about 5 minutes. Add the rice and garlic and cook, stirring constantly, for 1 minute. Transfer the mixture to a 3 1/2 quart slow cooker. Add the tomatoes with their juice, clam juice, water, worcestershire, thyme, oregano, salt, black pepper, and cayenne pepper. Break up the tomatoes with the side of a spoon. Cover and cook until the rice is barely tender, 5-6 hours on low. Meanwhile, in a medium skillet over medium heat, cook the sausage, turning often, until browned, about 5 minutes. During the last 15 minutes of cooking, stir the sausage, shrimp, and scallops into the jambalaya. Increase the heat to high, cover, and cook just until the shellfish are firm. Serve immediately.