The wells are designed to permit drilling, landing the tree, and completion using a conventional floating drilling rig. Tub-ingless completions are a part of the prototype SPS, as this design fits the requirements of the system. The wells will have the capability of vertical reentry workover if necessary.
Control of valves and other parts of the SPS is through a closed hydraulic system as a basic power source. The pressure in the system is subsea-generated with all equipment mounted on a replaceable skid.
The system is designed so there is a hydraulic sump on the low-pressure side of every packing. Thus, if there is any leakage, it is from a high-pressure to a low-pressure hydraulic system. There are no seals with high-pressure hydraulics on one side and seawater on the other. The low-pressure system is maintained at a slight amount above sea pressure. This pressure is maintained by equilibrating hydraulic pressure with seawater pressure, but at a lower elevation than any point in the hydraulic system. This difference in hydraulic head from the two fluids creates the difference needed to prevent seawater contamination of the hydraulic system.
The hydraulic pump is electrically driven (3 hp) through a submarine power cable. This multiconductor cable also carries the communications circuits. Hydraulic-pressure generation is automatic, but may be controlled from the surface to maintain 3,000 psi in the system.
A gas-type accumulator in the system provides sufficient energy to continue routine operations, opening and closing of valves, etc. for a 7-day period in case of power failure. This allows sufficient time for repairs to be made before the failsafe system automatically shuts in the production system.
Was this article helpful?
What you need to know about… Project Management Made Easy! Project management consists of more than just a large building project and can encompass small projects as well. No matter what the size of your project, you need to have some sort of project management. How you manage your project has everything to do with its outcome.