CML (Controlled Mud Level) is a dual gradient type of Managed Pressure Drilling (MPD). The CML system was developed and implemented on the Troll field to allow for reducing the annular pressures acting on the wellbore during drilling, thus allowing drilling areas weakened by faults and fractures and longer horizontal sections in the depleted normal pressured reservoirs.

This paper will present a short introduction to the Troll field, a description of the system utilized, a summary of the rig integration, operations and experiences with the CML system on Troll.

Keywords:
drilling fluid management & disposal, drilling fluids and materials, Upstream Oil & Gas, return line, Troll Field, reservoir section, SPM, annular pressure drilling, riser, marine riser
Subjects:
Pressure Management, Drilling Fluids and Materials, Pipelines, Flowlines and Risers, Drilling fluid management & disposal, Risers
Copyright 2019, IADC/SPE Managed Pressure Drilling and Underbalanced Operations Conference and Exhibition
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