Ingenieur April-June 2016 Ingenieur Apr-June 2016 | Page 57

FEATURE Constructability of Integrated and Modular Type Fixed Offshore Installations By A Rahim Baharudin, K Anwar M Othman, W Suzainorhapiz W Sulaiman, Petroliam Nasional Berhad Picture by Divulgação Petrobras, CC BY 3.0 br. Taken from wikimedia.org. T he development of offshore oil and gas (O&G) fixed offshore installations (FOI) has taken place for many years. Various construction methods have been employed, both integrated and modular types included. Although projects may appear similar in nature, they are unique in many ways. Many projects have experienced schedule delays and cost overruns due to poor feasibility and constructability studies. Hence, selecting the most suitable construction method is essential to ensure that the project meets its target production date, is within budget and of acceptable quality while remaining economically attractive and technically feasible. This article explores the key selection drivers and expounds the merits and demerits of both integrated and modular type superstructures for an offshore surface facility. Historical Data Historically, offshore O&G projects in South East Asia (SEA) have adopted both Integrated Concept (IC) and Modular Concept (MC) construction methods, amongst many others. Figure 1 depicts data sampling over the past 15 years, showing that both methods are equally popular. However, it can be observed that as the weight of the topsides increases, IC becomes the preferred construction option. Similar preference can also be seen when the water depth increases. 55