Dynamic Flexible Riser Ancillary Equipment—North Sea Asset Integrity Management Experience and Lessons Learned

2020 ◽  
Vol 143 (3) ◽  
Author(s):  
Damir Tadjiev
Keyword(s):  
Case Studies ◽  
North Sea ◽  
Oil And Gas ◽  
Lessons Learned ◽  
Operational Experience ◽  
Flexible Riser ◽  
Remotely Operated Vehicle ◽  
Integrity Management ◽  
Flexible Risers ◽  
Ancillary Equipment

Abstract Dynamic flexible risers are complex engineered systems, which provide a connection between topside (normally floating) facilities and subsea pipeline infrastructure on offshore oilfields. Such systems require the use of ancillary equipment to ensure the riser’s correct configuration is maintained throughout the service life. Industry experience shows that the integrity management of riser ancillary equipment is not always comprehensive, and failure of such equipment is one of the causes of premature removal of flexible risers from service. This article presents some case studies from the operational experience of dynamic flexible risers by an operator in the UK North Sea covering a period of approximately 20 years. The case studies look at the anomalies identified in service by general visual inspection (GVI) using a remotely operated vehicle (ROV) and the lessons learned. Some of the anomalies, had they not been identified and addressed promptly, could have resulted in costly repairs, which demonstrates the importance of inspecting the ancillary equipment of flexible risers as a part of the riser integrity management strategy. The challenges associated with integrity management of ancillary equipment of dynamic flexible risers are also discussed. The case studies presented in this article demonstrate that ROV GVI is an effective method for identifying installation and in-service anomalies related to flexible riser ancillary equipment. The purpose of this article is to share lessons learned with the wider offshore oil and gas community. It is also believed that the information presented in this article may provide useful information to other users of dynamic flexible riser systems when developing and/or implementing their subsea pipelines integrity management programs.

Brazil Subsea Processing & Boosting Technologies Yard: More Than 20 Years of Lessons Learned

2021 ◽  
Author(s):  
Marcello Augustus Ramos Roberto ◽  
Herbert Prince Koelln ◽  
Rodrigo Iunes De Rezende
Keyword(s):  
Oil And Gas ◽  
Water Injection ◽  
Gas Production ◽  
Lessons Learned ◽  
Operational Experience ◽  
Oil And Gas Production ◽  
Disruptive Technologies ◽  
Electrical Submersible Pumps ◽  
Offshore Oil And Gas ◽  
Offshore Oil

Abstract Over the last 20 years Brazil has been the stage where subsea processing and boosting (P&B) technology has supported and pushed the offshore oil and gas production to overcome its challenges and maximize field production and recovery factor. Subsea Oil-Water and Gas-Liquid Separation Systems, Multiphase Pumps, Electrical Submersible Pumps, Raw Water Injection Systems, and other innovative, enabler, optimizer or even disruptive technologies have been developing and applying in Brazil's fields to increase the NPV of projects and make feasible long tiebacks scenarios. This paper will present a retrospective of the most significant P&B systems developed and deployed in Brazil's fields, their operational experience, lessons learned, the next generation under development to surpass Pre-Salt and brown fields challenges and some initiatives to maximize these technologies applications.

Ensuring That Fatigue is Managed in Oil and Gas Operations

2021 ◽  
Author(s):  
Alexandra Holmes ◽  
Cristina Ruscitto ◽  
Sarah Booth
Keyword(s):  
Data Collection ◽  
Case Studies ◽  
Oil And Gas ◽  
Oil And Gas Industry ◽  
Lessons Learned ◽  
Site Location ◽  
European Working ◽  
Hours Of Work ◽  
Job Role ◽  
The Impact

Abstract As in any shiftworking industry, fatigue poses a hazard to workers within the oil and gas industry, irrespective of job role and site location. In order to demonstrate adherence to health and safety regulations, operators can be expected to manage shift patterns and hours of work, such that they are appropriate and do not result in unnecessary levels of fatigue that may reduce the safety of the operation. Reliance on hours of work limitations (for example the European Working Time Directive) or industry normalised working patterns may no longer be considered sufficient to ensure that the risk posed by fatigue is appropriately managed. This paper presents how a scientific approach can be applied and adapted to suit the context and the populations being studied in order to answer specific operational questions and provide tailored fatigue risk mitigations. It describes a method by which site and job role fatigue levels can be assessed, in order for appropriate controls to be implemented. It will use case studies to illustrate how data collection methods are tailored to reflect specific operational environments. Data collection is particularly important in parts of the industry where common shift arrangements differ from those which have historically been studied. The method outlines an approach to rigorously assess contributors to fatigue and fatigue levels in an organisation following appropriate scientific methods. Both subjective and objective data are collected, using methods such as fatigue and sleepiness scales, sleep diaries and collection of objective sleep data using validated sleep tracking devices. The approach is specifically tailored to the population of interest – reflecting their shift pattern, and collecting further data on workload, task demand, and operational or location-specific factors (for example travel to site, onsite sleeping facilities, or sea sickness on floating platforms). The method also allows for inferences to be made about the impact of circadian misalignment and shift timing on sleep, performance and mood. The method presented in this paper has been used in field data collection in two very different environments. These studies are used as case studies to examine how the methodology can be tailored to ensure that the collected data are appropriate to the operation being studied, and lessons learned to improve the methods in the future.

Multi-Objective Collaborative Flexibility Optimization Design of the Strengthening Layer of a Flexible Riser

2021 ◽  
pp. 1-32
Author(s):  
Zhixun Yang ◽  
Lifu Wang ◽  
Jun Yan ◽  
Dong Yan Shi ◽  
Zhirui Fan ◽  
...  
Keyword(s):  
Cylindrical Shell ◽  
Optimization Design ◽  
Oil And Gas ◽  
Bending Stiffness ◽  
Flexible Riser ◽  
Cross Sectional ◽  
Multi Objective ◽  
Flexible Risers ◽  
Ocean Environment ◽  
Torsion Stiffness

Abstract Marine flexible risers are widely used in ocean oil and gas extraction, and need to withstand environment loads (wave and current) and the large offset of the floater. Therefore, the flexible riser is subjected to tension, bending and torsion loads, which are mainly resisted by the key strengthening layer. Small bending stiffness of a cross section of the strengthening layer with larger tension and torsion stiffness are required to be compliant with the ocean environment. The traditional design of the key strengthening layer is partially rigid with larger cross-sectional stiffnesses. Therefore, the innovative configurations of the strengthening layer are imperative to make sure that the flexible riser is reliable and safe during the installation and operation. The strengthening layer of the flexible riser is treated as the cylindrical shell composed of periodic unit-cell beam structures, which is a hypothetical model. The optimization design is conducted through the novel implementation of the asymptotic homogenization (NIAH) method. The multi-objective collaborative flexibility optimization formulation of cylindrical shell structure is proposed, considering the ratio of cross-sectional tensile torsion stiffness to bending stiffness of the strengthening layer as the objectives. The optimal configuration results, the helically wound structures, are obtained, which are the alternative strengthening components of flexible risers. Finally, the optimal structures are compared with the commonly used marine flexible riser, which gives a great verification of the methodology feasibility, and explains why the strengthening layer is designed as the type of helically wound structure.

The Installation of Flexible Risers and Flowlines Systems With PLET on the Subsea End

2017 ◽  
Author(s):  
Kee Chien Ting ◽  
Kishor Chavan ◽  
Samuel Balmford ◽  
Daniel Sullivan
Keyword(s):  
Gulf Of Mexico ◽  
Deep Water ◽  
Oil And Gas ◽  
Intermediate Structure ◽  
Flexible Riser ◽  
Flexible Risers ◽  
Offshore Oil And Gas ◽  
Offshore Oil ◽  
Flexible Products

Flexible riser and flowline systems used in offshore oil and gas developments in shallow and deep water are typically terminated with vertical connectors with goosenecks or with horizontal connectors. An alternative arrangement is to terminate with PLET although it is not as commonly adopted. PLETs usually have a sizeable dimension and weight compared to the vertical and horizontal connectors hence present handling and deployment issues. A number of flexible risers and flowlines terminated with PLETs recently installed in a deepwater development in Gulf of Mexico showed that with careful engineering such deployment is viable and can be performed safely by a typical flexlay vessel. The installation engineering, installation aid requirements, the deployment methodology are presented and discussed. The observations from ensuing offshore operation showed that the flexible torsion and twist during deployment need to be carefully monitored and managed offshore. Flexibles terminated with PLETs could be potentially suitable where life of field gooseneck load may be excessive or for bigger and stiffer flexible products where making the 2nd end connections might be a challenging undertaking offshore. A PLET could also be used where an intermediate structure is required along a MEG line for example where In-Line Terminations (ILTs) are needed for flying leads plug-in. This would save on requirement for an intermediate structure and connectors.

scholarly journals Mechanical Analysis of Flexible Riser with Carbon Fiber Composite Tension Armor

2020 ◽  
Vol 5 (1) ◽  
pp. 3
Author(s):  
Haichen Zhang ◽  
Lili Tong ◽  
Michael Anim Addo
Keyword(s):  
Oil And Gas ◽  
Fiber Composite ◽  
Mechanical Analysis ◽  
Flexible Riser ◽  
Carbon Fiber Composite ◽  
Design Strength ◽  
Oil And Gas Exploration ◽  
Axial Tensile ◽  
Flexible Risers ◽  
Damage Theory

As oil and gas exploration moves to deeper areas of the ocean, the weight of flexible risers becomes an important factor in design. To reduce the weight of flexible risers and ease the load on the offshore platform, this paper present a cylindrical tensile armor layer made of composite materials that can replace the helical tensile armor layer made of carbon steel. The ACP (pre) of the workbench is used to model the composite tension armor. Firstly, the composite lamination of the tensile armor is discussed. Then, considering the progressive damage theory of composite material, the whole flexible riser is analyzed mechanically and compared with the original flexible riser. The weight of the flexible riser decreases by 9.73 kg/m, and the axial tensile stiffness decreases by 17.1%, while the axial tensile strength increases by 130%. At the same time, the flexible riser can meet the design strength requirements of torsion and bending.

New Techniques for Integrity Management of Flexible Riser-End Fitting Connection

2008 ◽  
Author(s):  
Mauro G. Marinho ◽  
Claudio S. Camerini ◽  
Sergio R. Morikawa ◽  
Daniel R. Pipa ◽  
Gustavo P. Pires ◽  
...  
Keyword(s):  
Stress Measurement ◽  
Failure Mechanisms ◽  
Optical Fiber Sensor ◽  
Fiber Sensor ◽  
Flexible Riser ◽  
New Techniques ◽  
Integrity Management ◽  
Flexible Risers ◽  
Surface Monitoring ◽  
Important Indication

As the operation water depth for flexible risers increases, the stress level in these structures also increases. This higher load, associated with stress concentration close to end fitting, can induce fatigue damage in tensile armors at riser top section. Progressive rupture of wires due to fatigue, which may be accelerated by corrosion, is an important indication of deterioration in riser-end fitting connection, and has become a typical failure mechanism for flexible riser top section. In order to mitigate the progression of these damages, apart from the inspection program and the surface monitoring procedures already implemented, techniques for the early detection of failure mechanisms at the riser-end fitting connection, specially at the tensile armors, are under development. This paper describes and evaluates these techniques, such as visual torsion monitoring, detection through acoustic emission of tensile armor wire rupture, electromagnetic tensile armor stress measurement and monitoring through optical fiber sensor extensometers, as well as reports the results obtained from field experience.

scholarly journals Development of KPI’s for Ageing Export Pipelines in the UK North Sea

2021 ◽  
Vol 9 (12) ◽  
pp. 1784-1790
Author(s):  
Olutayo Opeyemi Ogunmilua
Keyword(s):  
North Sea ◽  
Oil And Gas ◽  
Degradation Mechanism ◽  
Oil And Gas Industry ◽  
Third Party ◽  
Gas Industry ◽  
Efficient Management ◽  
Integrity Management ◽  
The Uk ◽  
Fatigue Corrosion

Abstract: Export pipelines are of inestimable value to the oil and gas industry, as they have continuously provided a path and means for hydrocarbon transportation. The most recent report from the UK HSE shows that there are about 1372 pipelines installed in the UK North-sea and about 442 of them are ageing export pipelines. The most unique function of these pipelines is to convey fluids from HC wells to the available processing facility; which are applicable for both onshore and offshore applications. During the useful life of these pipelines, they encounter various degradations that range from fatigue, corrosion, thermal expansion, spans, erosion and many other associated third-party challenges. It is the responsibility of duty holders to ensure that these degradations do not propagate into triggering hazardous and catastrophic incidents, to this effect, it is necessary for operators to protect the state of these pipelines by the application of an efficient management structure known as Pipeline Integrity Management System (PIMS). Keywords: Pipeline, Export, Ageing, Key Performance Indicators, PARLOC, OGP, Management, Integrity, Degradation Mechanism, Mitigation, PIMS.

An Analytical Approach for Predicting the Collapse Pressure of the Flexible Risers With Initial Ovalization and Gap

2019 ◽  
Author(s):  
Xiao Li ◽  
Xiaoli Jiang ◽  
Hans Hopman
Keyword(s):  
Analytical Approach ◽  
Oil And Gas ◽  
Gas Production ◽  
Analytical Models ◽  
Flexible Riser ◽  
Flexible Pipe ◽  
Collapse Pressure ◽  
Initial Imperfections ◽  
Collapse Strength ◽  
Flexible Risers

Abstract A flexible riser is a flexible pipe that transports materials between seafloor and topside structures. As oil and gas production heads to water depths greater than 3000 meters, huge hydrostatic pressure may cause the collapse failure of flexible risers. Generally, the collapse strength of a flexible riser is designed by considering the effects of initial imperfections, e.g., ovality of the carcass, and radial gap between the carcass/liner and pressure armor. These two imperfections may cause a significant reduction in the collapse strength of flexible risers under the flooded annulus condition. However, there are few analytical models available in the public literature that could take those factors into account. In this paper, an analytical approach is presented to predict the critical collapse pressure of the flexible risers with initial imperfections. The analytical results were compared with the numerical simulation, which showed reasonably good agreement.

scholarly journals Using Text Mining to Estimate Schedule Delay Risk of 13 Offshore Oil and Gas EPC Case Studies During the Bidding Process

Energies ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1956
Author(s):  
Byung-Yun Son ◽  
Eul-Bum Lee
Keyword(s):  
Text Mining ◽  
Case Studies ◽  
Research Methodology ◽  
Oil And Gas ◽  
Risk Index ◽  
Lessons Learned ◽  
Project Schedule ◽  
Schedule Delay ◽  
Offshore Oil And Gas ◽  
Offshore Oil

Korean offshore oil and gas (O&G) mega project contractors have recently suffered massive deficits due to the challenges and risks inherent to the offshore engineering, procurement, and construction (EPC) of megaprojects. This has resulted in frequent prolonged projects, schedule delay, and consequently significant cost overruns. Existing literature has identified one of the major causes of project delays to be the lack of adequate tools or techniques to diagnose the appropriateness and sufficiency of the contract deadline proposed by project owners prior to signing the contract in the bid. As such, this paper seeks to propose appropriate or correct project durations using the research methodology of text mining for bid documents. With the emergence of ‘big data’ research, text mining has become an acceptable research strategy, having already been utilized in various industries including medicine, legal, and securities. In this study the scope of work (SOW), as a main part of EPC contracts is analyzed using text mining processes in a sequence of pre-processing, structuring, and normalizing. Lessons learned, collected from 13 executed off shore EPC projects, are then used to reinforce the findings from said process. For this study, critical terms (CT), representing the root of past problems, are selected from the reports of lessons learned. The occurrence of the CT in the SOW are then counted and converted to a schedule delay risk index (SDRI) for the sample projects. The measured SDRI of each sample project are then correlated to the project’s actual schedule delay via regression analysis. The resultant regression model is entitled the schedule delay estimate model (SDEM) for this paper based on the case studies. Finally, the developed SDEM’s accuracy is validated through its use to predict schedule delays on recently executed projects with the findings being compared with actual schedule performance. This study found the relationship between the SDRI, frequency of CTs in the SOW, and delays to be represented by the regression formula. Through assessing its performance with respect to the 13th project, said formula was found to have an accuracy of 81%. As can be seen, this study found that more CTs in the SOW leads to a higher tendency for a schedule delay. Therefore, a higher project SDRI implies that there are more issues on projects which required more time to resolve them. While the low number of projects used to develop the model reduces its generalizability, the text mining research methodology used to quantitatively estimate project schedule delay can be generalized and applied to other industries where contractual documents and information regarding lessons learned are available.

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