Background
In 2013 our client were awarded a 5-year contract to provide Petrobras with Drill Pipe Riser (DPR) systems for the deep water Pre-Salt fields. Based on the earlier work completed by Proserv for the Early Production Riser (EPR) system, Proserv was awarded a total of nine controls systems for the DPR.
These control systems operate as an Installation and Work Over Controls (IWOCS) for deep water operations in Brazil. As well as supporting the control of the subsea operations including the emergency disconnect, well control, tree and downhole smart functions, the DPR control systems also provide control for the Tubing Hanger Running Tools and Suface Test Trees
Solution
The DPR systems are run as a rental unit with our client supplying operation and maintenance personnel and Proserv supporting operations in Brazil
This includes reeler, umbilical, drill pipe, stress joint, and transition joints within the scope along with the operational and maintenance services from Macaé.
The use of a DPR system enables installation and work over on vertical trees in open water without the use of a drilling riser. Annulus services are provided by a 1.5” 10K HCR core within the umbilical.
Scope
Each of the nine control systems consists of a surface Hydraulic Power Unit and a Control Cabin operating in a Zone 1 Hazardous Area. The Surface Control Unit within the Control Cabin operates logic and interfaces with a Drill Floor operator screen, ESD panel and the HPU
At the end of the Drill Pipe Riser a Subsea Control Module operates up to 40 functions on the subsea tree stack up at three separate pressure levels supplied from the umbilical. An Automatic Disconnect Valve and shutdown functionality ensures safe disconnection should the Floating Drilling Unit lose position or the umbilical become severed.
Dual electronics within the SCM provides redundancy and with an ROV recoverable SCM the system is optimised for work over uptime.
Conclusion
The use of production controls standard testing and reliability along with intervention system knowhow provides Petrobras with a Deep Water Installation and Work Over solution
Benefits
High reliability and redundancy
Optimised Uptime
Three selectable pressure levels for flexibility
State of the art electronics and connectivity
Remote connectivity
Mobile and hazardous area usage