Managed-Pressure Cementing Implemented in an Exploratory Ultradeepwater Well
This paper describes the path to implementation of full casing rotation during primary cementing jobs.
The focus of the complete paper is the planning and execution of an ultradeepwater managed-pressure-cementing (MPC) job in the Gulf of Mexico. From the onset of planning, the base case was to integrate a managed-pressure system into the drilling program to mitigate predicted pore-pressure (PP) uncertainty, pressure ramp increase, and narrow PP/fracture-gradient (FG) window operations, including drilling, tripping, and running casing. Although MPC was not originally in the scope of work, it was required because of the tight drilling window and was successfully executed.
The well is in Mexican waters at a depth of 10,748 ft. Given the exploratory nature of the well, a pressure ramp was predicted that would demand an excessive number of casing strings if a conventional approach were used.