Heat vegetable oil in a large casserole pot over medium heat. Add venison mince and cook until browned, 5 to 7 minutes. Add red peppers, carrots and onion; cook until onion has softened, about 3 minutes. Mix in garlic and cook until fragrant, about 30 seconds more. Stir in chilli powder, salt, paprika, cumin, oregano, pepper, garlic powder and onion powder. Cook for 1 to 2 minutes.
Mix in tomato puree and cook, stirring constantly, for 2 minutes. Add ale; cook and stir for 2 to 3 minutes. Stir in tomatoes and cook until juices start to release, about 3 minutes. Pour in chicken stock, water and treacle; stir to combine. Add beans and bay leaves.
Allow chilli to simmer, stirring occasionally. Reduce heat to medium-low and cook until flavours blend, 30 to 45 minutes more. Taste, adjust seasoning and discard bay leaves before serving.