Designphilosophy.doc

1、I. Design philosophy1. Crude oil production, separation and treatingThe GOM facility required more equipment for crude oil production, separation and treating due to the lower well productivity, lower surface flowing temperature and requirements for lower RVP for sales. The GOM design had a manifold

2、 allowing each well to be produced into any one of three stages of bulk separation, heating, electrostatic oil treater and dry/wet oil tanks.The North Sea facility had all wells routed to the first stage separator, no oil treater, cooling for stabilization, a surge vessel but no dry oil tank.2. Gas

3、compression and treatingGOM facility had no provision for lowering hydrocarbon dewpoint. It included a triethylene glycol system designed for 7lb /MMSCF water content in the sales gas.The North Sea system included a propane refrigeration system to chill the gas for both water and hydrocarbon dewpoin

4、t control.3. Produced water treatment and disposalThe GOM facility included two stages of water treating (CPI and Flotation) while the North Sea facility utilized flash separation and one stage of water treating (Flotation).4. Waterflood systemThe GOM facility utilized natural gas stripping and cart

5、ridge filters.The North Sea facility utilized sand filtration and vacuum degassing.5. Power generationIn GOM, compressors and pumps greater than approximately 500 HP normally have their own prime mover. With the waterflood pumps, pipeline pumps, main compressor and high pressure booster compressor a

6、ll being driven by turbine prime movers, three 850 KW generators are sufficient for remaining electrical load.The North Sea philosophy operated motor driven pumps and provided a large central power generation facility. Two 23 megawatt turbine generators sets were selected for thisstudy. No spare uni

7、t was provided as the waterflood load can be shed temporarily while a unit is being serviced.6. ElectricalIn the GOM design Control cables and 480 volt power cables are run to each motor which is not part of a major package. The compressors, waterflood pumps, pipe1i ne pumps and quarter packages eac

8、h have one set of 480 volt cables run to them with individual motor starters included in their control panels. Miscel1aneous, 120 volt and 208 volt branch feeders are used for lighting, space heaters, etc.In the North Sea facility, three voltage levels are utilized. The 11,000 volt system feeds the

9、large horsepower motors such as the 4,000 HP waterflood pump motors, the refrigeration compressor motor and the pipeline pumps. The sea water lift pump motors are run off of the 3300 volt system and the remaining motors are run off of the 415 volt system.7. InstrumentationGOM platform has local pneu

10、matic process control with a pneumatic shutdown system. Each major piece of equipment has a local shutdown panel which sends and receives single pneumatic signals to and from the central .shut-down panel. A 12 VDC control provides a mimic of this panel in the quarters building. The main prime movers

11、 each have their own local electro pneumatic panel which provides for start-up and shut-down sequencing, operational control and the sending and receiving of status and shutdown signal s to and from the central shut-down panel.North Sea instrumentation is generally electronic with RTUs (remote termi

12、nal units) and PLCs (programmable logic controllers) for constant monitoring, and analysis of platform information in the main control room and onshore if desired. This type of control system requires over forty interconnecting control logic units for various platform package systems. Each module is

13、 equipped with platform status lights and a public address system with telephones for direct communications with other modules or the main control room.8. Fire protectionThe Gu1f of Mexico platform has a firewater loop supplied by electric motor driven seawater pumps. It has no fixed spray system or

14、 diesel powered firewater pump.In the North Sea facility the protection systems for each process module consist of water deluge, fixed hose reels and portable fi re extinguishers. Four diesels driven fire pumpslocated in pairs in different modules are provided. Firewalls isolate process modules and

15、the HVAC system is interconnected with the fire protection system.9. Heating and VentilationThe Gu1f of Mexico system has open modules with no requirement for heating and ventilation.In North Sea design, two separate ventilation systems completely isolated from one another. One system operates under a slightly