This paper will review the hull design together with topsides process modules and functions. It will also focus on the schedule challenges during construction in Korea, the steel crisis and the yards workloads. The global supply chain and management of the contractors and main subcontractors will also be addressed.
Designed and built by Dalia Mar Profundo (DMP), a consortium of Technip / Saipem / Stolt in the TSS joint venture together with Samsung Heavy Industries (SHI) and Daewoo Shipbuilding & Marine Engineering (DSME) in Korea, the FPSO is 300 metres long and 60 metres wide capable of 2 millions barrels oil storage at an average production capacity of 240,000 barrels per day. It has a "total liquid" handling capacity of 405,000 barrels per day and a gas compressing capacity of 8 million sm3 per day. A special seawater treatment for sulphate removal module is incorporated. SHI undertook the task of building the 55,000 tonnes double skinned hull and "about half" of the topside modules. DSME completed the remaining modules and undertook the installation and integration of all the topsides modules before sail away. TSS had the responsibility for onshore pre and final commissioning.
The FPSO is moored with a 12 point chain spread linked to 17 metre high, 106 tonnes suction anchors and attached to the vessel by 120 mm diameter, sheated cables 1,800 metres long, with 100 metre chain segments at either end. Weight control was very effective maintaining the weight within the original targets.
For more details refer to Dalia paper OTC 18538.
Refer to Figure 1 for the general field layout with the FPSO and its mooring lines, above the subsea production facilities.
Figure 1 - Dalia Development Layout (available in full paper)
The 300 metre by 60 metre new build FPSO, weighs over 85,000 tonnes dry and with a surface area of more than four football pitches, was designed and built by the DMP consortium. With storage for up to eight days at the average plateau production of 240,000 barrels per day, the twin train process system has two stages for oil separation. Each train is designed for 55% of the total capacity, to give better reliability of the separation system. After dehydration and desalting, also undertaken in two phases, the oil is cooled down to 50°C before storage.
Produced water is treated and re-injected into the reservoir for pressure maintenance. Seawater is treated to complement the total injection capacity of 405,000 barrels of water per day. Produced gas is used as fuel and the balance is re-injected in the reservoir until export to the future Angola LNG plant. Three 24 MW Gas turbines generate the power on the FPSO. These gas turbines are dual fuel and run on high quality diesel at start-up and during periods when gas is not available. Anchored in the Dalia field in September 2006 by the 12 mooring lines spread, the FPSO is built to remain in place for the design life of 20 years.
