A very large hydrocarbon production vessel (10) of at least 40,000 tons steel weight, is constructed without requiring a very long reserve time period in a very large dry dock. The hull of the vessel is constructed in at least three different hull sections, including a midship hull section (24) and bow and stern hull sections (20, 22), with each preferably constructed at a different construction site. The hull sections are then brought together in a very large dry dock and welded together, so a minimum amount of time must be reserved in the very large dry dock. The midship hull section is preferably constructed in a specialized shipyard, and the same shipyard installs drilling equipment (50) and equipment that connects to risers that bring up hydrocarbons, so the expertise of the shipyard is used for both the midsection hull construction and specialized drilling and riser handling equipment.