Managed Pressure Drilling (MPD) is typically used for mature reservoirs where pressure is low due to depletion. 

MPD provides a well pressure equal to or slightly higher than the formation pressure. This is done by applying a light drilling fluid and surface pressure control. 

MPD is “built-in” when using RDM 

RDM offers significant advantages for drilling reservoirs with pressure challenges: 

• Precise well pressure control facilitates operations in wells with narrow operating pressure window.
• Improved ECD control prevents pressure variations during pump start and stop.
• Active drilling fluid volume can be reduced by more than 50% making fluid influx/ losses easier to detect and remedy. 
• RDM provides the opportunity of avoiding loss of the annular well fluid by adding a physical barrier in the annulus, especially important in depleted zones.

RDM provides a smaller area footprint – the Flow Control Unit is approximately 5 m2, especially important offshore where deck space is limited. This is due to RDM reducing the pressure in the return line, whereas competing MPD solutions is dependent on comprehensive choke systems for the same purpose. 

Precise pressure control is a prerequisite for the drilling of long horizontal sections

 Well pressure needs to be inside the pore and fracture pressure window along the whole horizontal well length. 

• In conventional MPD, ECD in open hole can limit horizontal reach. 
• With RDM there is no flow in the wellbore annulus, hence the gradient is static, removing physical limitations.

> The RDM technology pages provide more information on components and technology used to exercise MPD.