When using an oil-based foundation, it is essential to choose a primer that complements its formulation. Here are a few options to consider:

1. Silicone-based primer: Silicone-based primers create a smooth and even base for makeup application. They can help to fill in pores and fine lines, providing a flawless finish. Since silicone-based formulas are not oil-based, they can work well with oil-based foundations without compromising their longevity.

2. Water-based primer: Water-based primers are lightweight and can provide hydration to the skin without adding any excess oil. They create a smooth canvas for makeup application and can help the foundation adhere better to the skin. Look for water-based primers that are specifically formulated to work with oil-based foundations.

3. Oil-based primer: If you prefer a primer that matches the oil-based nature of your foundation, you can opt for an oil-based primer. These primers can help to enhance the longevity of your foundation and provide additional hydration to the skin. Look for oil-based primers that contain nourishing ingredients like jojoba oil, argan oil, or rosehip oil.

Remember to always patch test new products and consider your skin type when choosing a primer. Additionally, ensure that you cleanse your skin thoroughly at the end of the day to remove any oil-based products and prevent clogged pores.