INNOVATIVE FIELD DEVELOPMENT SCHEMES: ENABLING TECHNOLOGIES FOR LONG SUBSEA OIL TIEBACKS

摘要

The exploitation of subsea fields will be increasingly challenging in the future if technically feasible and/or profitable field development is to be achieved. Indeed, subsea production and transportation systems are set to become more complex because of the challenges linked to their characteristics and/or the need for new development systems. The combination of distance and water depth alongside the need for safe and reliable product transportation and cost reductions, considering the current Oil & Gas price scenario, are the factors that need to be taken into consideration. Innovative solutions are needed above all in the case of long distance tiebacks, very deep water applications or when the fluid temperature at the wellhead is too low to manage the entire transport distance without incurring in flow assurance problems during normal or transient conditions. This paper will focus on challenging subsea oil fields and, hence, the use of insulated and heated pipeline systems and subsea processing elements such as subsea boosting. SAIPEM has conducted numerous studies and carried out in-house development activities on this subject bearing in mind the foreseeable needs of operators in future fields under investigation. The scope of this paper is to present the results of these activities, with special reference to Long Subsea Oil Fields Tiebacks. New development systems and operating philosophies have been identified along with technologies that, in some cases, SAIPEM is developing jointly with major suppliers. The most efficient production system of those studied was selected at the end of a screening process that also involved the definition and conceptual design of the technological building blocks. These building blocks were further studied from the point of view of market ownership and readiness. The feedback received from technology suppliers and O&G operators was incorporated in the promising overall system configuration selected and was enabled by technologies ranging from Subsea Active Heating/Insulation and Subsea Boosting to the Subsea Power Distribution and All-Electric Control System. The Subsea Power Distribution and All Electric Control System offers an overall investment cost reduction, especially if coupled with subsea chemical injection, and facilitates tiebacks to an existing facility due to the flexibility of the operations and its compatibility with a wide range of project design bases. The paper also illustrates the technological state-of-the-art of the selected field development system, with special focus on the subsea power distribution and all-electric control system philosophies, their application and associated behavior.