Managed-pressure drilling (MPD) was developed to help drill wells that have a very close pore and frac pressure gradient. Commonly required in soft marine sediments and in shallow land drilling, MPD is also used in specific cases, such as deep wells. Cementing operations in such conditions are very challenging and require special attention to cement the string while reducing risk of losses or flow. The innovative managed-pressure-cementing technique (MPCT) was used to cement several string sizes that sat at different depths ranging from 2,000 m up to 6,500 m, in water depth exceeds 1,000 m. In this challenging deepwater environment, specialized surface equipment was used to control the well during cementing. In addition, the mud properties and cement system were tailored for this specific operation.

This paper illustrates the importance of MPCT in wells cementing operations to minimize cement and mud losses, secure well during cementing and reduce risk of formation damage. After cementing, the jobs were evaluated using different techniques including observation of fluids returns at seabed, end of job pressure versus simulated job pressure and with sonic and ultrasonic logging tools. The success of the MPCT enabled us to reduce completion costs and achieve drilling objectives.