Drilling mud, also known as drilling fluid, is a mixture used in the drilling of boreholes, particularly for oil and gas extraction. It serves several purposes, including cooling and lubricating the drill bit, removing cuttings from the well, and maintaining pressure to prevent blowouts. The composition of drilling mud can vary, but it typically includes water, clay, and various additives to enhance its properties. There are two main types: water-based mud and oil-based mud, each chosen based on the specific conditions of the drilling site and the desired performance characteristics.