Waterflooding is a method used in oil extraction to increase the amount of crude oil that can be recovered from a reservoir. This technique involves injecting water into the oil reservoir to maintain pressure and push the oil towards production wells. By doing so, it helps to displace the oil and makes it easier to extract. The process of waterflooding can enhance oil recovery significantly, often improving the yield by 20% to 50%. It is commonly used in mature oil fields where natural pressure has declined, ensuring that more oil can be accessed and produced efficiently.