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MPD - Managed Pressure Drilling technologies have been successfully implemented over the last decade. The technique is also frequently used on floating drilling units. MPD is primarily understood as a technique where back pressure is applied in combination with a low density mud weight and a Rotating Control Device (RCD) - effectively raising the bell nipple into the derrick of the drilling rig. However, within the MPD segment there is a sub-group defined as Dual Gradient Drilling (DGD). These techniques are specific for floating drilling units and allow the use of a higher, overbalanced mud weight. EC-Drill is a technique that falls within the DGD segment. In its current form it is not providing "full dual gradient", instead it is eliminating the effect of dynamic circulating pressure (ECD) and enabling drilling with a close to constant bottom hole pressure (BHP). This may still impact well design by allowing casing points to be extended. The technique is ideal low mud weight environments and depleted fields where lowering the mud weight to allow for application of back-pressure may be impossible. EC Drill is also a valuable tool in loss regimes and it may be used to ensure good cement jobs in deep water preserving the integrity of the well. A subsea mud pump is connected to the riser annulus where it controls annulus pressure by manipulating the fluid level within the riser - effectively lowering the bell nipple under water. The change in bottom hole pressure is directly related to the change in fluid level - or suction pressure of the subsea pump. Contrary to MPD with back pressure, this additional system or equipment is not part of the primary well barrier. The EC-Drill technology has been successfully deployed on jack-ups and on s SEMIS in deep water. The Paper will present the technology and some case histories