In deepwater offshore fields where spread moored FPSOs are involved, theproduced oil is generally offloaded to shuttle tankers via Oil Offloading Lines(OOLs) connected between the FPSO and deepwater buoy. Until recently, two typesof Oil Offloading Lines (OOL) were used for the transfer of stabilized crudeoil between the FPSO and the offloading buoy: steel pipe or unbonded flexiblepipe. Since 2000 Trelleborg and SBM have been working on an alternativeoffloading solution made of bonded flexible hoses called TRELLINE™ (seereference [1]). This product can be adapted to a large range of applicationslike for the offloading of oil from a MOPUstor to a submerged loading system(SLS). In September 2005, the TRELLINE™ was used for OOL for the first time for SNEPCOwho decided to supplement the existing Bonga OOL system with one 20" IDTRELLINE™ to match with ultra short delivery. In December 2006, the OOL wasinstalled with the SBM vessel Dynamic Installer (see reference [2]). In July 2008, Total Exploration Production Angola (TEPA) decided to use theTRELLINE™ for the 18" ID OOLs of the Pazflor field. For Pazflor, the producedoil is exported from the FPSO to the buoy located 1,856m away, via twoidentical 18" OOLs of 2,070 m long, made of 175 hoses sections each. The OOLsare connected to the FPSO and the buoy by the means of gimbal tables thatdecouple the tension and bending loading. Specificity of Pazflor Trelline hoseswas their hig desing pressure equal to 50 bars that had required intensivequalification and testing program, and making Pazflor export lines a" world-first". Based on past installation experiences on Bonga project (OOL) for SNEPCO in2006 and on Yme project (SLS) for Talisman Energy Norge in 2008, see reference[3]), a new installation method has been developed. A specifically designedpatented equipment was developed to ensure a safe and quick offshoreinstallation. It comprises:An A-Frame designed to upend individual hose from deck to the fireline.An assembly platform designed for vertical assembly of the hoses.A large deployment wheel ensuring the transition from vertical to horizontalof the OOL at the sea surface. In June 2011, the SBM vessel Normand Installer successfully installed the twoPazflor OOLs. The two OOLs were assembled and hooked up in less than 4 weeks(mobilizations included). The TRELLINE™ OOL system demonstrated its advantages in term of design, procurement cost, lead time, installation efficiency and operationaladvantages. It will further demonstrate maintenance advantages.
Moving LNG production to an offshore setting certainly presents a serious set of challenges for the offshore oil and gas industry, particularly when it comes to the design and construction of FLNG facilities which need to maintain the utmost levels of safety and give increased flexibility to LNG production while withstanding the effects of winds, waves and currents in the open seas. With the first FLNG plants now in production and twenty other planned FLNG projects worldwide, it is safe to say that over the past few years these challenges have been overcome and these facilities have well and truly demonstrated their economic and technical viability to the industry. But while some challenges have certainly been met, others remain.The environmental conditions of the current FLNG locations are at present quite mild and only require the use of the most straightforward technology for the unloading of the LNG, e.g. marine loading arms. But, with prospective new FLNG locations moving away from these 'mild' areas, to sites where sea states, wind and currents can be much more severe, only tandem LNG offloading systems appear to meet the challenges of the application as they improve safety, operability and availability.Since 2009, Trelleborg has been developing floating cryogenic hoses which ensure LNG offshore transfer with minimum BOG generation, combine high flexibility, reliability and long service life, and also meet LNG operator and contractor's offloading requirements related to safety, flowrate capacity and operation availability. Through latest acquisition, this technology has been even further enhanced, with new parameters being put forward for the development of these hoses in order to become a key component in offloading systems for future offshore FLNG projects.This white paper will discuss Trelleborg's 20Љ ID cryogenic hose development and qualification program and outline why tandem offloading solutions are a viable alternative for the industry -not only limiting downtime, but also improving safety. The paper will present in this case the innovative offshore LNG offloading system using cryogenic floating hoses which has been jointly developed with Saipem since 2009 and about to be qualified according to EN1474 standard requirements.
The LNG market remains in relative infancy in terms of the development of infrastructure to meet increasing supply and demand. Given its unique make-up compared to traditional oil and gas transposition, new and innovative means of transferring LNG have had to emerge; factoring the unique composition of LNG (i.e. chemical and physical properties) and the critical importance of safety while loading and unloading. Moreover, LNG Infrastructure is moving into new frontiers for a variety of reasons. LNG exporters are seeking new markets and evolution of small and medium scale LNG demand will necessitate splitting of LNG into smaller load parcels. Power generation, and LNG terminals, are being constructed in locations that have traditionally been ‘off-grid’ – disconnected from pipelines. More flexible options are required to fit a broader range of vessel sizes, locations, weather conditions and infrastructure conditions. One key element in unlocking new transfer options is fresh thinking around ship-to-shore transfer and the development of game-changing floating composite cryogenic hose technology. Composite LNG hoses typically consist of multiple, unbonded, polymeric film and woven fabric layers encapsulated between two stainless steel wire helices – one internal and one external. Essentially, the film layers provide a fluid-tight barrier to the conveyed product, with the mechanical strength of the hose coming from woven fabric layers. The number and arrangement of multiple polymeric film and woven fabric layers is specific to the hose size and application. The polymeric film and fabric materials are selected to be compatible with the conveyed product and the operating temperatures likely to be encountered. This technology cost-effective technology has enabled a recalibration of traditional thinking around ship-to-shore LNG transfer. Designed for fatigue resistance in even the most hazardous conditions, cryogenic floating hose technology typically provides a viable alternative to traditional jetty-based transference in circumstances that would make such infrastructure unfeasible – for example, harsh environments, areas where water is too deep to accommodate jetty construction, or too shallow to allow large vessels to moor alongside. These cryogenic hoses also expand options for offshore ship-to-ship transfers in a broader range of locations; for example, in tandem configuration, vessels can be moored as much as 300 to 500 meters away from a storage unit. This enables ship-to-ship transfer in deeper waters in even the most challenging conditions - with the increased separation distance mitigating the risk of collision and ensuring the safety of the vessels and crew. In this paper, we will discuss the multiple applications of cryogenic floating hose technology and how it is re-shaping ship-to-shore and ship-to-ship transfer.
Moving LNG production to an offshore setting presents a demanding set of challenges. Along with the design and construction challenges of developing FLNG facilities, extra thought has been required regarding the transfer of the product; LNG transfer must now battle with the effects of winds, waves, and currents in open seas. In environments where conditions are much more demanding, conventional marine loading arms will not suffice as they could result in a shut-down of the liquefaction plant in bad weather conditions. This paper outlines why tandem offloading solution that rely on the use of flexible hoses are a viable alternative for the industry -not only limiting downtime, but also improving safety. Hydrodynamics analyses have been performed to demonstrate that the performances of such an offloading system are in compliance with targeted environments and associated operating envelope. Key results of this study will be introduced here. This paper will also discuss why -in the absence of mature solutions -different actors have been joining forces to develop and qualify an innovative LNG tandem offloading solution using floating hoses that fully satisfies the industry's requirements. It will be shown how the joint industrial program has been benefiting from diverse inputs coming from an IOC, an EPC contractor, a hose manufacturer and a University laboratory specialized in flow assessment.Finally, as an illustration of such a successful JIP, significant information will be given about pressure drop analysis within a flexible cryogenic hose based on advanced CFD models and small scale water/LNG flow tests.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.