Ivanhoe/Rob Roy Flexible Riser System

1991 ◽  
Author(s):  
S.N. Smith ◽  
I.L. Mercer
Keyword(s):  
Flexible Riser

A time domain prediction method for the vortex-induced vibrations of a flexible riser

2018 ◽  
Vol 59 ◽  
pp. 458-481 ◽  
Author(s):  
Mengmeng Zhang ◽  
Shixiao Fu ◽  
Leijian Song ◽  
Xiaoying Tang ◽  
Yue He
Keyword(s):  
Time Domain ◽  
Prediction Method ◽  
Flexible Riser ◽  
Vortex Induced Vibrations ◽  
Domain Prediction

Flow Assurance Issues Related to Flexible Riser and Pipeline System Configuration

2014 ◽  
Author(s):  
Leyuan Yu ◽  
Saif Mohammad ◽  
Scott Button ◽  
Mingxiu Li
Keyword(s):  
Flow Assurance ◽  
Pipeline System ◽  
System Configuration ◽  
Flexible Riser

Adaptive robust barrier‐based control of a 3D flexible riser system subject to boundary displacement constraints

2021 ◽  
Author(s):  
Ge Ma ◽  
Zhifeng Tan ◽  
Yiming Liu ◽  
Zhijia Zhao ◽  
Tao Zou
Keyword(s):  
Flexible Riser ◽  
Boundary Displacement ◽  
Displacement Constraints

Optimization Applied to Buzios Flexible Riser Systems and Subsea Layout

2021 ◽  
Author(s):  
Vinicius Gasparetto ◽  
Thierry Hernalsteens ◽  
Joao Francisco Fleck Heck Britto ◽  
Joab Flavio Araujo Leao ◽  
Thiago Duarte Fonseca Dos Santos ◽  
...  
Keyword(s):  
Deep Water ◽  
Technology Use ◽  
Capital Expenditure ◽  
Lessons Learned ◽  
Internal Diameter ◽  
Flexible Riser ◽  
Flexible Pipe ◽  
Injection Wells ◽  
Gas Field ◽  
Field Development

Abstract Buzios is a super-giant ultra-deep-water pre-salt oil and gas field located in the Santos Basin off Brazil's Southeastern coast. There are four production systems already installed in the field. Designed to use flexible pipes to tie back the production and injection wells to the FPSOs (Floating Production Storage and Offloading), these systems have taken advantage from several lessons learned in the previous projects installed by Petrobras in Santos Basin pre-salt areas since 2010. This knowledge, combined with advances in flexible pipe technology, use of long-term contracts and early engagement with suppliers, made it possible to optimize the field development, minimizing the risks and reducing the capital expenditure (CAPEX) initially planned. This paper presents the first four Buzios subsea system developments, highlighting some of the technological achievements applied in the field, as the first wide application of 8" Internal Diameter (ID) flexible production pipes for ultra-deep water, leading to faster ramp-ups and higher production flowrates. It describes how the supply chain strategy provided flexibility to cover the remaining project uncertainties, and reports the optimizations carried out in flexible riser systems and subsea layouts. The flexible risers, usually installed in lazy wave configurations at such water depths, were optimized reducing the total buoyancy necessary. For water injection and service lines, the buoyancy modules were completely removed, and thus the lines were installed in a free-hanging configuration. Riser configuration optimizations promoted a drop of around 25% on total riser CAPEX and allowed the riser anchor position to be placed closer to the floating production unit, promoting opportunities for reducing the subsea tieback lengths. Standardization of pipe specifications and the riser configurations allowed the projects to exchange the lines, increasing flexibility and avoiding riser interference in a scenario with multiple suppliers. Furthermore, Buzios was the first ultra-deep-water project to install a flexible line, riser, and flowline, with fully Controlled Annulus Solution (CAS). This system, developed by TechnipFMC, allows pipe integrity management from the topside, which reduces subsea inspections. As an outcome of the technological improvements and the optimizations applied to the Buzios subsea system, a vast reduction in subsea CAPEX it was achieved, with a swift production ramp-up.

Experimental Investigation of the Effects of the In-Line Top-Motion on the Vortex-Induced Vibration Response of a Flexible Riser

2021 ◽  
Author(s):  
Bo Tong ◽  
Chuanzhen Ma ◽  
Zhuang Kang ◽  
Cheng Zhang ◽  
Shaojie Li
Keyword(s):  
Experimental Investigation ◽  
Vibration Response ◽  
Flexible Riser ◽  
Vortex Induced Vibration

Cathodic Protection Design Consideration for an Offshore Flexible Riser Connected to an Impressed Current System

2021 ◽  
Author(s):  
Thierry Dequin ◽  
Clark Weldon ◽  
Matthew Hense
Keyword(s):  
Cathodic Protection ◽  
Sacrificial Anode ◽  
Flexible Riser ◽  
Flexible Pipe ◽  
Linear Resistance ◽  
Flexible Pipes ◽  
Flexible Risers ◽  
Impressed Current ◽  
Host Structure ◽  
Impressed Current Cathodic Protection

Abstract Flexible risers are regularly used to produce oil and gas in subsea production systems and by nature interconnect the subsea production system to the floating or fixed host facilities. Unbonded flexible pipes are made of a combination of metallic and non-metallic layers, each layer being individually terminated at each extremity by complex end fittings. Mostly submerged in seawater, the metallic parts require careful material selection and cathodic protection (CP) to survive the expected service life. Design engineers must determine whether the flexible pipe risers should be electrically connected to the host in order to receive cathodic protection current or be electrically isolated. If the host structure is equipped with a sacrificial anode system, then electrical continuity between the riser and the host structure is generally preferred. The exception is often when the riser and host structure are operated by separate organizations, in which case electrical isolation may be preferred simply to provide delineation of ownership between the two CP systems. The paper discusses these interface issues between hull and subsea where the hull is equipped with an impressed current cathodic protection (ICCP) system, and provides guidance for addressing them during flexible pipe CP design, operation, and monitoring. Specifically, CP design philosophies for flexible risers will be addressed with respect to manufacturing, installation and interface with the host structure’s Impressed Current Cathodic Protection (ICCP) system. The discussion will emphasize the importance of early coordination between the host structure ICCP system designers and the subsea SACP system designers, and will include recommendations for CP system computer modeling, CP system design operation and CP system monitoring. One of the challenges is to understand what to consider for the exposed surfaces in the flexible pipes and its multiple layers, and also the evaluation of the linear resistance of each riser segment. The linear resistance of the riser is a major determinant with respect to potential attenuation, which in turn largely determines the extent of current drain between the subsea sacrificial anode system and the hull ICCP system. To model the flexible riser CP system behavior for self-protection, linear resistance may be maximized, however the use of a realistic linear resistance is recommended for evaluation of the interaction between the host structure and subsea system. Realistic flexible linear resistance would also reduce conservatism in the CP design, potentially save time during the offshore campaign by reducing anode quantities, and also providing correct evaluation of drain current and stray currents.

Gas-liquid two-phase severe slugging in a pipeline-riser system with S-shaped flexible riser: Experiments and modeling

2013 ◽  
Author(s):  
Nailiang Li ◽  
Liejin Guo ◽  
Wensheng Li
Keyword(s):  
Flexible Riser ◽  
Two Phase

Experimental investigation on the suppression of vortex-induced vibration of long flexible riser by multiple control rods

2012 ◽  
Vol 30 ◽  
pp. 115-132 ◽  
Author(s):  
H. Wu ◽  
D.P. Sun ◽  
L. Lu ◽  
B. Teng ◽  
G.Q. Tang ◽  
...  
Keyword(s):  
Experimental Investigation ◽  
Flexible Riser ◽  
Multiple Control ◽  
Vortex Induced Vibration ◽  
Control Rods

Riser Concept Selection for FPSO in Deepwater Norwegian Sea: A Case Study

2018 ◽  
Author(s):  
Arvind Keprate ◽  
R. M. Chandima Ratnayake
Keyword(s):  
Literature Review ◽  
Geographical Location ◽  
Weather Conditions ◽  
Large Vessel ◽  
Concept Selection ◽  
Flexible Riser ◽  
Norwegian Sea ◽  
Daunting Task ◽  
Selection For

Selecting a riser concept for FPSOs stationed in deep water has posed challenges, due to the high hydrostatic pressure and large vessel payload. One of the major factors governing the riser concept selection for deepwater FPSOs is the geographical location and weather conditions prevalent in the region. For example, the free hanging flexible riser has been mostly used in the moderate environments of offshore Brazil, while concepts like the SCR and Hybrid Riser Tower (HRT) are dominant in the calm weather conditions of the West of Africa (WoA). Selecting a riser concept for an FPSO stationed in harsh weather conditions like those of the Northern Norwegian Sea is a daunting task. This is due to the large vessel offsets and dynamics, which are directly transferred along the riser’s length to its base, thereby causing considerable fatigue damage to the riser. The main aim of this paper is to recommend a suitable riser concept, which may be hooked to an internal turret moored FPSO stationed in water of 1500m depth and in the harsh environmental conditions of the Northern Norwegian Sea. The recommendations are based on the literature review and the case study performed in the manuscript. On the basis of the literature review, a lazy wave configuration of flexible riser and Steel Lazy Wave Riser (SLWR) has been considered as a viable riser concept. Thereafter, a case study is performed to compare the two riser concepts, on the basis of vessel payload, fabrication cost and installation cost.

Quick Connection Couplings in the Permeated Gas Relief Systems of Flexible Riser End Fittings

2011 ◽  
Author(s):  
Alexandre S. Rabelo ◽  
Antonio M. R. Motta ◽  
Antonio P. G. Romero ◽  
Joa˜o Paulo C. e S. Nunes ◽  
Jose´ A. P. Padilha ◽  
...  
Keyword(s):  
Fluid Injection ◽  
Main Function ◽  
Monitoring And Control ◽  
Flexible Riser ◽  
Relief Valve ◽  
Monitoring And Control System ◽  
Fitting In ◽  
Relief System ◽  
And Control ◽  
Vacuum Testing

The objective of the paper is to present a new conception for the permeated gas relief system of flexible riser end fittings. The new conception is based on a multi-function gas relief system, depending on the requirements established by the operators. The main function of the system is to relief the accumulated gas in the riser annulus. Due to the interconnection of the annulus to the external environment through the top end-fitting, other functions of this system may be required such as to allow fluid injection into the annulus or vacuum testing, for example. The presented conception of the permeated gas relief system is based on the usage of quick connection and disconnection couplings. It was firstly developed focusing the particular cases of submerged top end fittings but it can be applicable in both situations where the riser top end fitting is located either at an emerged or a submerged position. In the course of its development, the conception has led to different patterns of the system, depending on the different required functions. The gas relief system was conceived in order to allow — in an easy and quick manner, without the risk of flooding the annulus with seawater — the execution of typical operations like those required for installing a monitoring and control system, for injecting fluids into the annulus, for vacuum testing or, additionally, for removing any damaged relief valve from the end fitting in order to substitute it for a new one. The paper describes the components of the gas relief system for each required function. The idea is to have many interchangeable items of standardized sets that meet specific requirements, case by case. The performance of the permeated gas relief system is an important issue for flexible riser integrity.

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