Extending the MPD engineering analysis into lower-completion string designs in addition to the MPD approach during drilling operations has proven critical in mitigating operational challenges in a multi-well campaign offshore Ivory Coast. This location is known for depleted reservoirs and highly unstable formations which result in tripping, casing and completions runs to be very challenging when using a conventional approach.
The use of MPD concepts, techniques and equipment allowed for the prediction of maximum tripping speeds and expected bottomhole pressures by conducting detailed surge analyses before designing and running the lower-completions string. Rigorous hydraulic simulations were run, detailing lower-completions string assemblies with over 200 components as well as incorporating open hole caliper logs to model well pressure outcomes as accurately as possible. These results were critical in facilitating the decision-making of completion string designs and their running parameters. Additionally, the wells were drilled with a combination of a lower mud density and MPD equipment which contributed to a well-defined drilling pressure window.
This novel approach of MPD incorporation into completions design was implemented in four wells successfully, has saved cost and time, and with zero non-productive time compared to wells where an MPD approach was not used to design and run completion strings, and proven key to successfully drill and complete wells in the region.