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January 2012 www.sname.org/sname/mt harsh environment units is the deck box. e deck box is a watertight upper portion of the hull, incorporated for the following purposes: r 4 U S F O H U I F O U I F I V M M T U S V D U V S F r . J O J N J [ F U I F W J C S B U J P O G S P N U I F U P Q T J E F T r þÿ 1 S P W J E F F Y U S B S F T F S W F C V P Z B O D Z J O U I F F W F O U the platform is accidently listed for more than the designed inclination. Ballast systems and ballasting procedures also are critical items on modern semisub- mersible units. Challenges associated with correct ballasting include lling ballast tanks via lift pumps located outside the columns (no hull penetrations below the operational draft), and the ability to transfer ballast water between tanks. Advancements in computer technology over the past 20 years, especially in 3D vir- tual reality, have made a tremendous impact on oshore facility design. Designers are able to create an integrated 3D-model database, which enables the entire development team to share and review the design model periodically during the engineering phase. Hull designers have slowly adopted these technologies and methods to create larger and safer platforms more quickly and efficiently. The topsides and hull designers can now work seamlessly in multiple locations globally, within multiple disciplines and perspectives, to identify and address many safety and operational issues inherent in a design project, before the plat- form is built. ese issues include: r þÿ Q P U F O U J B M D M B T I F T C F U X F F O T U S V D U V S B M N F N -bers and piping which are dicult to detect with 2D technology?benefits include reduced modications and schedule delays r þÿ C F U U F S N B U F S J B M I B O E M J O H E F T J H O X I J D I means safer onboard processes r þÿ B O E D P O T J T U F O D Z C F U X F F O E S B X J O H T T Q F D J -cations, and virtual reality, which helps to achieve client objectives. Future challenges Floating production systems have evolved greatly from the early examples of the 1970s to current systems that meet the most demanding requirements. New semisubmersible units are operating, or are planned, in water depths of up to 7,100 ft. (2,1645 m) in the Gulf of Mexico and elsewhere, and incorporate the latest advanced systems and technology. Today?s units are designed around a fundamen- tally dierent design philosophy, which is to operate safely at all times, employ sustainable practices to protect the envi- ronment, and withstand the most extreme metocean conditions. In the future, objectives will include greater safety and increased protection of the environ- ment. Part of this will be reducing manning requirements on oshore facilities. is goal will require production facilities to be designed with more automation, more redundancy, and better remote control systems to be able to minimize the number of persons onboard. e hull will likewise be designed with the abil- ity to correct a list or compensate for accidental ooding from a remote location. Still another trend will be to increase the application of sustainable practices in the operation of the units, including zero discharge onboard utility systems, cleaner emissions from prime movers, and reliable pollution barriers between the hydrocarbons and the sea. Many of these practices are now incorporated in the latest generation of facili- ties. Future oating production units will be able to operate safely in extreme weather, per- haps enabling remote shutdown and restart after a hurricane event. Most importantly, operators will have the ability to drill and produce the more com- plex reservoirs with fundamentally safer and more reliable well system technology. MTMichael Praught is director for GVA North America (a KBR company) in Houston, Texas. Derren Liu is busi- ness development manager with GVA North America. Fþÿ a c i l i tACILIT Y þÿ tTYPþÿ eE Fþÿ uUNþÿ c t i oCTIONþÿ a l i tALIT Y Sþÿ c a l a b i l i tCALABILIT Y þÿ c oCONþÿ s t r a iSTRAI Nþÿ t sTS INþÿ s t a l l a t i oSTALLATIO N þÿ aAND þÿ c o m m i s s i oCOMMISSIONþÿ iINþÿ gG Fþÿ l e x i b i l i tLEXIBILITY Semisubmersible Wet trees; subsea BO þÿ PP drilling, completion, intervention Limited envelope of SCR applicability Installation relatively simple compared to Spar/TL þÿ PPRelatively simple de- commissioning, reloca- tion, and expansion compared to Spar/TL þÿ PPTLþÿ PP þÿ DDry or wet trees; sur- face BO þÿ PP drilling, com- pletion, intervention Water depth con- strained by tendons and payload to ap- proximately 5,000 ft. Installation relatively complex Limited exibility for decommissioning, relo- cation, and expansion Spar þÿ DDry or wet trees; sur- face BO þÿ PP drilling, com- pletion, intervention þÿ DDual-barrier production riser with increasing depth and pressure; very large payloads (> 25,000 tons) þÿ HHigh degree of com- plexity, cost, schedule risk Limited exibility for decommissioning, relo- cation, and expansion Fþÿ PPSO Wet trees; subsea BO þÿ PP drilling possible; in- tegrated oil storage Tower or lazy wave risers required for deeper water; accom- modates very large topsides Simplest topside integration, commis- sioning of all platform types; wet tow to site Simplest to expand topsides, relocate, or decommission TABLE 1. FLOATI þÿ NNG þÿ PPROþÿ DDUCTIO þÿ NN FACILITIES C þÿ HHARACTERISTICS 32_37_Praughtfeature_SNAME_Jan12_P3.indd 3712/22/11 3:39 PM