In the oil and gas industry, water injection—also known as waterflooding—involves pumping water into an oil reservoir to maintain reservoir pressure and push oil toward production wells.

This Enhanced Oil Recovery (EOR) method is the most common secondary recovery technique, significantly increasing the volume of oil that can be economically recovered by driving it toward the surface.

Water is typically sourced from external supplies or aquifers and injected through dedicated injection wells into the depleted reservoir to displace and mobilize the oil.