The first ever HPHT exploration well in Kalimantan was drilled by Swamp Barge Rig with narrow pressure window environment. The well was planned to be drilled using 2.9 SG mud weight to 4575 m vertical depth with 0.10 SG pressure window. Maximum predicted bottom hole temperature of the well was 186° C while the maximum expected wellhead pressure (MEWHP) reached 11,300 Psi. MPD becomes mandatory to complete the well and becomes a novel implement for swamp barge rig operation. Therefore, MPD workshop was held among the teams to ensure all personnel become familiar with the system. On other hand, the equipment configuration was set with some modifications to accommodate the operation requirement, contingency, tight stack up below rotary table and hoisting devices limitation. Rotating Control Device (RCD) was stacked up part by part on tight moon pool space. Several modifications were done properly and gave operation flexibility plus robust contingency. RCD alignment was reset periodically and natural rubbers were utilized to enhanced rubbers lifetime in high temperature condition. EKD system with Coriolis utilization was being main mitigation during drilling with limited kick margin that will allow reservoir section to be accessed. Formation pressure investigation was also performed to give additional information on formation pressure for better well assessment. SBP application on dual gradient tripping and managed pressure cementing give a means to secure the well safely and properly during high gas event with losses condition. As the result, MPD implementation enables the operator to complete HPHT exploration well on swamp barge rig project safely despite the complexity and risk of narrow formation pressure window operation.