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Air Products_March 2021


Building from scratch

Offshore Marine Technology: 4th Quarter 2019



For owners and operators seeking FPSO units, it’s become common to repurpose existing VLCCs for the task. However, offshore floating solutions specialist MODEC says that this may not be the most efficient method. “As a result of increases in required crude oil and gas production capacities, topsides have become bigger and heavier,” MODEC opines, in some cases exceeding 35,000tonnes overall.


Similarly, it's not unusual to find converted VLCCs whose production rates exceed 180,000 barrels per day, and demand is growing for larger onboard accommodation areas. These converted VLCCs can suffer from “insufficient deck space area and insufficient crude oil storage capacity”, the group continues. "Going forward, it is expected that there will be a heightened demand for newbuilt FPSO hulls"


In turn, MODEC has co-developed a pair of “next generation” FPSO hulls, the ‘MODEC New Offshore Adapted Hull (NOAH)’ and ‘MODEC 350’. The MODEC NOAH was developed with a spacious deck, capable of carrying larger, heavier and more complex topsides. At the same time, the hullform was designed to facilitate access to the onboard storage tanks.The NOAH’s design incorporates a modular approach, so that the owner can tailor the vessel to their particular project requirements – such as determining the mooring configuration. The hullform can also be tweaked to suit the vessel’s operational environment, taking into account wave, wind, current and tide conditions.


The NOAH would incorporate flat or 2D bending plates, which, MODEC says, can cut construction costs without sacrificing seakeeping. In March 2019, class society ABS granted the NOAH design Approval in Principle, with Bureau Veritas and DNV GL following suit in May.


Meanwhile, MODEC has co-developed a second “next generation” hullform for FPSO newbuilds, the M350 (pictured above), which was devised by MODEC and Dalian Shipbuilding Industry Co. Measuring 350m x 64m, and with a moulded depth of 33m, the M350 incorporates a full double hull, a storage capacity of 350,000m3 (2.2 million barrels), a helideck and sizeable living quarters for up to 160 persons. Instead of featuring a pump room, the M350 would offer a submerged cargo pumping system.


The M350’s deck area would span 18,000m2 – which, MODEC claims, is approximately 20% larger than that of a typical VLCC. As with the NOAH, the M350 can be customised to accommodate various mooring systems and MODEC’s modular topsides. Variants include: M350s (which would offer a spread mooring system); M350e (denoting an external turret); and M350i (for an internal turret).


MODEC adds that the hulls of either of the three variants can be delivered from the shipyard to the integration yard “in 24 months from EPC contract award”. Subsequent hulls thereafter would have a build schedule of “20 months or less”.