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The intermediate section in the South Mahakam field presented well control and instability risks due to severe loss circulations that were attributable to fractured carbonates. Pore pressure in places drops and becomee an underbalanced condition. Therefore, the sacrificial Sea Water (SW) was used. In the 1500m section, consisting dominantly of the carbonates, countermeasure for loss-curing with LCM/cement is impractical. Another constraint is the instability of shale intervals where SW can not inhibited sufficiently, making BHA and casing trips difficult. The section objective is to secure the next section intefrity by running and cementing casing safely and immediately. It a challenging under these conditions. MPD equipment was installed to allow for drilling in non-return condition. A Rotary Bearing (RB) gives the ability for continuous string movement, annulus pressure management and influx detection with filling up with SW in annulus. A specific setup which was an addition of a bigger diameter annulus injection line than the standard provided, allowed sufficient pumping rate to bullhead gas migration by SW. The specific MPD application in the field allowed a range of dispersive annular pressure readings at surface (0-150psi). This pressure range is caused by injection of drilled cuttings to the thief zones. Cuttings injection helps to bridge the fractures and thus stopp the loss. By correlations to Equivalent Static Density from real-time measurements and visual checks of fluid at surface, it was confirmed the desired bridging effect. A static condition at target depth then allowed well displacement to inhibitive mud to stabilize the shale and running casing cementing easily. With this MPD application, the operator ha managed to drill and complete over 20 wells within the field. The challenging conditions have overcome and standard procedures have been established. This paper will mention the detailed MPD surface setup and drilling practices under severe losses in the South Mahakam field. The applied specific practices have made a static well under the challenging condition.