This paper presents the ongoing development and qualification program of a subsea sulphate removal and injection system and provides an overview of the system together with the features that enable its operation subsea. The ongoing development program has completed a dry piloting phase that focused on the design of the system, subsystems, assembly of the pilot and qualification of the process, including the modified operation of the filtration technologies. This development is in cooperation with 5 leading global oil companies. The pilot operation took place over a period of 6 months.
Injection of seawater to provide reservoir pressure support is often the choice to increase oil recovery in a field. Traditionally, large and heavy topside processing systems are deployed to treat and inject seawater. This creates significant operational challenges, especially in brownfields, where topside space and weight capacity are constrained. Moving the system to the seabed will greatly reduce the capacity demand imposed on the floating facility and will eliminate the need for an expensive high-pressure riser and flowline system. The subsea system requires a different operational approach in which the conventional chemical cleaning is eliminated. Special design considerations must be made to maintain operational robustness without the chemical cleaning in place unit.
Baker Hughes and its partners are proposing to move the seawater treatment system to the seabed to simplify and debottleneck the topside facilities and reduce the total cost of ownership. Seawater treatment systems for injection are conventionally topside units. Necessary operational modifications have to be implemented to enable its reliable operation in subsea conditions. These modifications are being validated through piloting.