Collapse and Buckle Propagation of Sandwich Pipes: A Review

Author(s):  
Chen An ◽  
Menglan Duan ◽  
Segen F. Estefen

Sandwich pipes (SP) can be an effective solution for ultra-deepwater submarine pipelines, combining high structural resistance with thermal insulation. Most research work on this subject has been conducted at the subsea technology laboratory (LTS) of COPPE/UFRJ, with the aim of developing qualified pipes to transport deepwater oil and gas, especially for the pre-salt reservoirs at Offshore Brazil. This article reviewed most of the research done in recent years (2002–2012) on the buckling, collapse and buckle propagation of SP, which emphasized on the development of theoretical, experimental and numerical methods adopted to analyze such structural behavior of SP with different core materials. The main mechanical and thermal properties of the previously considered core materials were also given, together with the elastoplastic constitutive model for each material. The experimental and numerical results of collapse and buckle propagation under external pressure for SP were summarized. A general discussion of the mechanical failure modes of SP under external pressure was also provided. Besides, some suggestions for future work on collapse behavior and buckle propagation of SP were given.

Author(s):  
C An ◽  
B Q Liu ◽  
T T Li ◽  
G M Fu ◽  
M L Duan

Buckle propagation of local collapse appearing in the damaged pipes is one of the failure modes that are of particular interest for deepwater application. The local collapse can propagate along the pipeline for long distances in both directions when the external pressure magnitude is up to the propagation pressure. In this paper, the buckle propagation pressure of sandwich pipes (SP) with different material properties and geometric characteristics is investigated by numerical simulation using Python programming language based on general finite element code. The results of the pressure history data obtained are verified by comparing those published previously. The effect of material properties, geometric characteristics and adhesion conditions on the propagation pressure are analyzed.


Author(s):  
Luis D’Angelo ◽  
Hans M. Thorsen ◽  
Olav Fyrileiv ◽  
Leif Collberg ◽  
Sonia Furtado

Submarine pipelines are more often than before required to operate in harsh environments, especially for systems deployed in ultra-deep water. In order to minimize the installation tension due to the hanged section, they are installed empty and therefore the external pressure is often the prime load parameter for the design. New discoveries and associated technical challenges have generated important research and development endeavors in a wide range of disciplines in order to improve efficiency and reliability, but also keeping the risks associated with the new scenarios within an acceptable range. Some aspects that can be mentioned include, for instance, steel line grade improvements and manufacturing innovations of pipe products; more powerful lay vessels and development of new pipeline installation methods; determination of the mechanical behavior and the expected failure modes of concern for deep and long pipelines under combined loads; and the improved different design criteria like the DNV-OS-F101 (1) and API RP-1111 (2) codes. The intention of this paper is to review and compare three different pipeline design criteria well established in the oil and gas industry. The pipeline wall thickness design for pipe pressure containment (bursting), local buckling (system collapse) and propagating buckling for DNV-OS-F101 (1) and API RP-1111 (2) are discussed as well as the parameters used, definitions, safety philosophy and code limitations. A pipeline example is used to illustrate and compare the results.


2020 ◽  
Vol 162 (A1) ◽  
Author(s):  
C An ◽  
B Q Liu ◽  
T T Li ◽  
G M Fu ◽  
M L Duan

Buckle propagation of local collapse appearing in the damaged pipes is one of the failure modes that are of particular interest for deepwater application. The local collapse can propagate along the pipeline for long distances in both directions when the external pressure magnitude is up to the propagation pressure. In this paper, the buckle propagation pressure of sandwich pipes (SP) with different material properties and geometric characteristics is investigated by numerical simulation using Python programming language based on general finite element code. The results of the pressure history data obtained are verified by comparing those published previously. The effect of material properties, geometric characteristics and adhesion conditions on the propagation pressure are analyzed.


Author(s):  
Hossein Ghaednia ◽  
Jamshid Zohrehheydariha ◽  
Sreekanta Das ◽  
Rick Wang ◽  
Richard Kania

Pipeline is the common mode for transporting oil, gas, and various petroleum products. Structural integrity of oil and gas transmission pipelines is often threatened by external interferences such as concentrated load, impact load, and external pressure. These external interferences can cause ‘mechanical damage’ leading to structural failure in onshore and offshore linepipes. Lateral load is applied as a concentrated load on a small area of pipe segment and can cause local buckling, bend, dent, or out-of-roundness in the pipe. As an example, a concentrated load in buried onshore linepipe can occur if a segment of the linepipe rests on a narrow rock tip or even a narrow hard surface. Such concentrated lateral load may or may not cause immediate rupture or leak in the linepipe; however, it may produce out-of-roundness with or without a dent in the pipe cross section, which can be detrimental to the structural and/or operational integrity of the pipeline. Hence, the pipeline operator becomes concerned about the performance and safety of the linepipe if a pipe section is subject to a sustained concentrated load. A research work using full-scale tests and finite element method (FEM) was undertaken at the Centre for Engineering Research in Pipelines (CERP), University of Windsor to study the influence of various internal pressures and diameter-to-thickness ratios on the out-of-roundness of 30 in diameter (NPS 30) and X70 grade pipes with D/t of 90 when subjected to a stroke-controlled concentrated load. This paper discusses the test specimens, test setup, test procedure, test results, and FEM results obtained from this study.


Author(s):  
Claudio Moura Paz ◽  
Guangming Fu ◽  
Segen Farid Estefen ◽  
Marcelo Igor Lourenço ◽  
John Alex H. Chujutalli

Comprising an annular layer with adequate thermal insulation and structural resistance material enclosed by two concentric steel pipes, sandwich pipes could be an alternative for flowlines in ultra-deepwater for the pre-salt reservoirs in offshore Brazil. In this work, a numerical and experimental study was performed to investigate the collapse behavior of sandwich pipes considering the reel-lay installation method. Experimental models were manufactured using two different geometries of stainless steel pipes and strain hardening cementitious composites with PVA fiber (SHCC) in annular layer. One set of specimens was tested using a reel-lay apparatus and another set was kept intact. A hyperbaric chamber was then used to test both sets of specimens to collapse. The collapse resistance of the proposed sandwich structure was investigated, and the detrimental effect of the reeling strains to the collapse resistance was assessed. The numerical models simulated reeling and straightening loads during reel-lay installation and then the collapse under external pressure. The results were compared with experimental measurements and shown good agreement.


Author(s):  
Guangming Fu ◽  
Claudio Moura Paz ◽  
John Alex Hernández Chujutalli ◽  
Marcelo Igor Lourenço ◽  
Dirney Bessa de Lima ◽  
...  

Sandwich pipes (SP) combining high structural resistance with thermal insulation have been considered as an effective solution for using in ultra deepwater pipelines. Research has been conducted at COPPE/UFRJ with different core materials aiming to develop qualified pipes to transport deepwater oil and gas, especially for the pre-salt reservoirs in offshore Brazil. SPs using SHCC material are easy to manufacture and cost-effective. Moreover, the composition of the SHCC material can be controlled to achieve structural requirements along with good thermal insulation. Investigation on the buckling under external pressure and feasibility of installation by reel-lay method is required. This study presents numerical analysis of the collapse, collapse propagation and bending of sandwich pipes with different geometries. The Drucker-Prager formulation is employed for SHCC constitutive model and it is calibrated through small-scale tests. Model geometries match full scale specimens manufactured and tested in bending apparatus and hyperbaric chamber. Numerical/experimental correlation is also presented.


2020 ◽  
Vol 13 (3) ◽  
pp. 381-393
Author(s):  
Farhana Fayaz ◽  
Gobind Lal Pahuja

Background:The Static VAR Compensator (SVC) has the capability of improving reliability, operation and control of the transmission system thereby improving the dynamic performance of power system. SVC is a widely used shunt FACTS device, which is an important tool for the reactive power compensation in high voltage AC transmission systems. The transmission lines compensated with the SVC may experience faults and hence need a protection system against the damage caused by these faults as well as provide the uninterrupted supply of power.Methods:The research work reported in the paper is a successful attempt to reduce the time to detect faults on a SVC-compensated transmission line to less than quarter of a cycle. The relay algorithm involves two ANNs, one for detection and the other for classification of faults, including the identification of the faulted phase/phases. RMS (Root Mean Square) values of line voltages and ratios of sequence components of line currents are used as inputs to the ANNs. Extensive training and testing of the two ANNs have been carried out using the data generated by simulating an SVC-compensated transmission line in PSCAD at a signal sampling frequency of 1 kHz. Back-propagation method has been used for the training and testing. Also the criticality analysis of the existing relay and the modified relay has been done using three fault tree importance measures i.e., Fussell-Vesely (FV) Importance, Risk Achievement Worth (RAW) and Risk Reduction Worth (RRW).Results:It is found that the relay detects any type of fault occurring anywhere on the line with 100% accuracy within a short time of 4 ms. It also classifies the type of the fault and indicates the faulted phase or phases, as the case may be, with 100% accuracy within 15 ms, that is well before a circuit breaker can clear the fault. As demonstrated, fault detection and classification by the use of ANNs is reliable and accurate when a large data set is available for training. The results from the criticality analysis show that the criticality ranking varies in both the designs (existing relay and the existing modified relay) and the ranking of the improved measurement system in the modified relay changes from 2 to 4.Conclusion:A relaying algorithm is proposed for the protection of transmission line compensated with Static Var Compensator (SVC) and criticality ranking of different failure modes of a digital relay is carried out. The proposed scheme has significant advantages over more traditional relaying algorithms. It is suitable for high resistance faults and is not affected by the inception angle nor by the location of fault.


Author(s):  
Enrico Torselletti ◽  
Luigino Vitali ◽  
Erik Levold ◽  
Kim J. Mo̸rk

The development of deep water gas fields using trunklines to carry the gas to the markets is sometime limited by the feasibility/economics of the construction phase. In particular there is a market for using S-lay vessels in water depth larger than 1000m. The S-lay feasibility depends on the applicable tension at the tensioner which is a function of water depth, stinger length and stinger curvature (for given stinger length by its curvature). This means that, without major vessel up-grading and to avoid too long stingers that are prone to damages caused by environmental loads, the application of larger stinger curvatures than presently allowed by current regulations/state of the art is needed. The work presented in this paper is a result of the project “Development of a Design Guideline for Submarine Pipeline Installation” sponsored by STATOIL and HYDRO. The technical activities are performed in co-operation by DNV, STATOIL and SNAMPROGETTI. The scope of the project is to produce a LRFD (Load Resistant Factor Design) design guideline to be used in the definition and application of design criteria for the laying phase e.g. to S and J-lay methods/equipment. The guideline covers D/t from 15 to 45 and applied strains over the overbend in excess of 0.5%. This paper addresses the failure modes relevant for combined high curvatures/strains, axial, external pressure and local forces due to roller over the stinger of an S-lay vessel and to sea bottom contacts, particularly: • Residual pipe ovality after laying, • Maximum strain and bending moment capacity. Analytical equations are proposed in accordance with DNV OS F101 philosophy and design format.


2021 ◽  
Author(s):  
Emmanuel Ayodele ◽  
David Ekuma ◽  
Ikechukwu Okafor ◽  
Innocent Nweze

Abstract Drilling fluid are complex fluids consisting of several additives. These additives are added to enhance and control the rheological properties (such as viscosity, gel strength and yield point) of the mud. These properties are controlled for effective drilling of a well. This research work is focused on determining the rheological behavior of drilling mud using industry-based polymer and Irvingia Gabonensis (ogbono) as viscosifiers. Water based muds were formulated from the aforementioned locally sourced viscosifier and that of the conventional used viscosifier (Carboxylmetyl cellulose, CMC). Laboratory tests were carried out on the different muds formulated and their rheological properties (such as yield stress, shear stress, plastic viscosity and shear rate) are evaluated. The concentration of the viscosifiers were varied. The expected outcome of the research work aims at lowering the total drilling cost by reducing the importation of foreign polymer which promotes the development of local content in the oil and gas industry. The research compares the rheology of mud samples and the effect of varying the concentration (2g, 4g, 6g, 8g, and 10g) of both CMC and Ogbono and determining the changes in their rheological properties. The total volume of each mud sample is equivalent to 350ml which represent one barrel (42gal) in the lab. From the result, at concentration of 2g, the ogbono mud has a better rheology than the CMC mud, but at a concentration above 2g, CMC mud shows a better rheology than ogbono mud, that is, as the concentration of CMC is increased, the rheological properties of the mud increased while as the concentration of ogbono is increased the rheological properties decreased. The viscosity of the drilling fluid produced from the ogbono were lower than that of CMC, it could be used together with another local product such as cassava starch, offor or to further improve the rheology and then be a substitute to the conventional viscosifiers.


Author(s):  
С.К. Курбаниязов

В начале барремского времени море отступило и до начала позднего альба территория представляла собой низменную аккумулятивную равнину, в пределах которой происходило накопление аллювиальных и озерно-аллювиальных отложений: красно-коричневых глин, алевролитов с прослоями коричневых песчаников и песков и линзами темно-серого лигнита. В основании толщи отмечаются гравелиты и конгломераты. В раннемальбе произошла кратковременная трансгрессия моря, однако территория современного Восточного Приаралья не была затоплена и представляла собой прибрежно-морскую равнину, где накапливались глины, алевролиты и песчаники. К концу позднего альба море регрессировало, и территория вновь стала представлять собой низменную аллювиально-озерную равнину. По всей территории происходило накопление пестроцветных глин, зеленовато-серых алевролитов, песков и песчаников, а также углей. При проведении иследовательских работ были обоснованы наиболее перспективные типы ловушек углеводородного сырья по стратиграфическим уровням и выявлена зональность их распространения. Дана оценка перспектив района на выявление залежей нефти и газа. Выделены информативные и качественные признаки (критерии) нефтегазоносности. Обоснованы площади и конкретные структуры для постановки детальных поисковых работ на выявление залежей нефти и газа. Рассчитана оценка потенциальных ресурсов углеводородного сырья. At the beginning of the Barremian time, the sea receded and until the beginning of the late Alb, the territory was a low-lying accumulative plain, within which the accumulation of alluvial and lacustrine-alluvial deposits occurred: red-brown clays, siltstones with layers of brown sandstones and sands and lenses of dark gray lignite. Gravelites and conglomerates are noted at the base of the strata.In the Rannemalba, there was a short-term transgression of the sea, but the territory of the modern Eastern Aral Sea region was not flooded and was a coastal-sea plain, where clays, siltstones and sandstones accumulated. By the end of the Late Alb, the sea regressed and the area again became a low-lying alluvial-lacustrine plain. There was an accumulation of variegated clays, greenish-gray siltstones, sands and sandstones, as well as coals throughout the territory. During the research work, the most promising types of hydrocarbon traps were justified by stratigraphic levels and the zoning of their distribution was revealed. The assessment of the prospects of the area for the identification of oil and gas deposits is given. Informative and qualitative signs (criteria) of oil and gas potential are identified. The areas and specific structures for setting up detailed search operations to identify oil and gas deposits are justified. The estimation of potential resources of hydrocarbon raw materials is calculated.


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