Aker on Managed Pressure Operations

When Aker Solutions acquired Managed Pressure Operations in 2013, it became a provider of next generation continuous circulation and managed pressure drilling (MPD) systems, which has become a critical component to the drilling process going into the future. MPD systems have proven to be reliable, enabling maximum up time and significant cost savings and has been labeled of strategic importance for pre-salt drilling by Brazilian operator Petrobras, which uses MPD systems developed by Weatherford, which was the company that first introduced large scale use of the system to the industry. The MPD system being introduced by Aker/MPO is fully automated and simple to operate, needing few people to run the equipment.

An important part of the MPD system is the riser safety systems and riser gas handling system. According to Aker, the deepwater riser safety system (RSS) has been developed to enable safe handling of gas entry into the riser. In order to allow for easy installation on the rig, the RSS is designed to be installed below the tension ring. The two main components are the quick close annular and the flow spool, both of which will pass through a 49.5” rotary table. With this system in place, an influx can be safely routed from the riser, through the RSS manifold and out the ultra mud gas separator with no discharge to the environment.

Another important safety aspect of the MPD system is the deepwater kick detection system, because the conventional methods of kick and loss detection and subsequent well control procedures are inadequate for today’s ultra deepwater drilling requirements. Well control event detection and subsequent control measures are time critical. The longer the event detection time, the greater the consequential problem especially in the increasing risks of pre-salt drilling with fractured carbonates and higher pressure reservoirs. The deepwater kick detection and riser safety system used together is what Aker calls an open system. This system protects the rig 24 hours per day during every operation from when the riser is run until the riser is pulled and offers instant closure of the well once influx has been detected. The system can reduce kick volumes by a factor of 5.

Using Aker’s total control driller (TCD), automated MPD systems apply surface back pressure on the well bore using custom designed pressure control valves instead of conventional chokes. Mass flow rate, pressure, density and temperature are measured, processed and stored by the control and data acquisition system. The manifold then diverts all returned well bore fluid flow at atmospheric pressure, either directly to the shakers, or the drill through mud gas separator and then onto the shakers, the TCD manifold also incorporates a programmable dual overpressure protection system.