Dual gradient drilling is applicable in the deepwater industry. The drilling riser is filled with two different fluids mirroring the environments it runs through – between surface and mudline the riser is filled with seawater, and under the mudline the riser is filled with mud. Reducing the total pressure pushing down on the wellbore and the impact of water depth on well design, the pressure at the bottom of the wellbore nevertheless remains the same as seen in Single Gradient Drilling.