Development of cost-effective composite repair system for oil/gas pipelines

2018 ◽  
Vol 202 ◽  
pp. 802-806 ◽  
Author(s):  
E. Mahdi ◽  
E. Eltai
Author(s):  
Remy Her ◽  
Jacques Renard ◽  
Vincent Gaffard ◽  
Yves Favry ◽  
Paul Wiet

Composite repair systems are used for many years to restore locally the pipe strength where it has been affected by damage such as wall thickness reduction due to corrosion, dent, lamination or cracks. Composite repair systems are commonly qualified, designed and installed according to ASME PCC2 code or ISO 24817 standard requirements. In both of these codes, the Maximum Allowable Working Pressure (MAWP) of the damaged section must be determined to design the composite repair. To do so, codes such as ASME B31G for example for corrosion, are used. The composite repair systems is designed to “bridge the gap” between the MAWP of the damaged pipe and the original design pressure. The main weakness of available approaches is their applicability to combined loading conditions and various types of defects. The objective of this work is to set-up a “universal” methodology to design the composite repair by finite element calculations with directly taking into consideration the loading conditions and the influence of the defect on pipe strength (whatever its geometry and type). First a program of mechanical tests is defined to allow determining all the composite properties necessary to run the finite elements calculations. It consists in compression and tensile tests in various directions to account for the composite anisotropy and of Arcan tests to determine steel to composite interface behaviors in tension and shear. In parallel, a full scale burst test is performed on a repaired pipe section where a local wall thinning is previously machined. For this test, the composite repair was designed according to ISO 24817. Then, a finite element model integrating damaged pipe and composite repair system is built. It allowed simulating the test, comparing the results with experiments and validating damage models implemented to capture the various possible types of failures. In addition, sensitivity analysis considering composite properties variations evidenced by experiments are run. The composite behavior considered in this study is not time dependent. No degradation of the composite material strength due to ageing is taking into account. The roadmap for the next steps of this work is to clearly identify the ageing mechanisms, to perform tests in relevant conditions and to introduce ageing effects in the design process (and in particular in the composite constitutive laws).


Coatings ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 301
Author(s):  
Jiaqi Chen ◽  
Hao Wang ◽  
Milad Salemi ◽  
Perumalsamy N. Balaguru

Carbon fiber reinforced polymer (CFRP) matrix composite overwrap repair systems have been introduced and accepted as an alternative repair system for steel pipeline. This paper aimed to evaluate the mechanical behavior of damaged steel pipeline with CFRP repair using finite element (FE) analysis. Two different repair strategies, namely wrap repair and patch repair, were considered. The mechanical responses of pipeline with the composite repair system under the maximum allowable operating pressure (MAOP) was analyzed using the validated FE models. The design parameters of the CFRP repair system were analyzed, including patch/wrap size and thickness, defect size, interface bonding, and the material properties of the infill material. The results show that both the stress in the pipe wall and CFRP could be reduced by using a thicker CFRP. With the increase in patch size in the hoop direction, the maximum von Mises stress in the pipe wall generally decreased as the maximum hoop stress in the CFRP increased. The reinforcement of the CFRP repair system could be enhanced by using infill material with a higher elastic modulus. The CFRP patch tended to cause higher interface shear stress than CFRP wrap, but the shear stress could be reduced by using a thicker CFRP. Compared with the fully bonded condition, the frictional interface causes a decrease in hoop stress in the CFRP but an increase in von Mises stress in the steel. The study results indicate the feasibility of composite repair for damaged steel pipeline.


2009 ◽  
Author(s):  
Fragiskos A. Batzias ◽  
Phillip-Mark P. Spanidis ◽  
George Maroulis ◽  
Theodore E. Simos

Author(s):  
Chris Alexander

Although composite materials are used to repair and reinforce a variety of anomalies in high pressure transmission gas and liquid pipelines, there continues to be widespread debate regarding what constitutes a long-term composite repair. The United States regulations require that composite repairs must be able to permanently restore the serviceability of the repaired pipeline, while in contrast the Canadian regulations take a more prescriptive approach by integrating the ASME PCC-2 and ISO 24817 composite repair standards along with a requirement for establishing a 50-year design life. In this paper the author provides a framework for what should be considered in qualifying a composite repair system for long-term performance by focusing on the critical technical aspects associated with a sound composite repair. The presentation includes a discussion on establishing an appropriate composite design stress using the existing standards, using full-scale testing to ensure that stresses in the repair do not exceed the designated composite design stresses, and guidance for operators in how to properly integrate their pipeline operating conditions to establish a design life. By implementing the recommendations presented in this paper, operators will be equipped with a resource for objectively evaluating the composite repair systems used to repair their pipeline systems.


Author(s):  
Abu Salim ◽  
Marney D. Perry ◽  
John A. Krogue ◽  
Allen Walker

The oil and gas pipelines are spread around the world in all nations as complex networks. The increased usage of gas is rapidly increasing this network. These networks are generally made from various diameters of pipes. The pipelines are serviced on as required basis, using pig launcher and receivers to suit the pipe diameter. Pigs of different types may be launched in different sequences, to clean the pipes and to obtain various data related to pipe condition and location. The pig launching and receiving process uses rapid pressure changes in the launcher and receiver and some magnitude of impact may be experienced by the unit. This process also requires frequent access to the launcher/receiver unit. To have an efficient and cost effective usage of the launcher/receiver unit, it is essential to have a door mechanism, which is safe, robust, capable of the above loading conditions, requires minimum service and is easy to use. PECO has recently developed & designed a door, which incorporates ail the above requirements. The door was put to high pressure testing and the test results were so encouraging that PECO named it SafeLock® Closure. The design was developed with gas pipelines in mind. However it is equally applicable to vessels, exchangers and other metal openings where quick, frequent and easy access is required. Safety has been the prime concern through out the design and development process of this closure. Therefore the final product has resulted in a very safe closure. The initial design of the SafeLock® door / closure used a spring load to make it easy in operation. This was removed in the later design. The segmental blocks, usually called C-ring segments, are operated to move in and out of the shell-sub annulus. The closure opening and closing is performed by the use of a single lever arm. This way only one person can operate (open and close) the door / closure. For opening and closing, the lever-arm needs to be rotated less than 40 degree angle. The rotation direction of the lever arm in closing is reverse of that in opening. The door / head can be fully retrieved from the shell-sub and rest by the side of the launcher/receiver to provide complete access to the opening. This door / closure provides quick access to launcher / receiver, pig traps, meter provers, filter vessel, scrubber, scraper, manway to pressure vessel, etc. This closure can be mounted in the vertical or horizontal position. During change of filter elements, launching a pig, quick access to container under pressure, this closure door is designed to provide a safe and fast service. The construction, operation, design details and application of the new closure door are included in this paper and explained with the help of the design diagrams and photographs.


2014 ◽  
Vol 875-877 ◽  
pp. 1063-1068 ◽  
Author(s):  
Park Hinn Chan ◽  
Kim Yeow Tshai ◽  
Michael Johnson ◽  
Hui Leng Choo

The static and cyclic failure mechanisms of offshore pipe riser repaired with a designated laminate orientation of carbon/epoxy (C/E) system were studied. The finite element (FE) model takes into account failure mechanisms of the composite sleeve inter-layer delamination, debonding at the steel riser-composite surface interface, and the maximum permissible strain of the repaired riser. Design conditions of the combined static loads (coupled internal pressure, longitudinal tensile and transverse bending) were determined through a limit state analysis [1,2]. The limiting static bending load that causes catastrophic failure under a coupled internal pressure and tensile loadings was determined through Virtual Crack Closure Technique (VCCT). The effects of cyclic bending, mimicking the typical scenarios experienced in pipe riser exposed to dynamic subsea environment, were evaluated and compared against the static conditions. The low cycle fatigue of the composite repair system (CRS) is simulated using a direct cyclic analysis within a general purpose FE program, where the onset and fatigue delamination/disbonding growth are characterized through the Paris Law.


Author(s):  
Neil Woodward ◽  
Kjell Edvard Apeland ◽  
Jan Olav Berge ◽  
Richard Verley ◽  
Mike Armstrong

Over the last 10 years Statoil has developed subsea remote hot tap technology. The first use of the remote hot tap technology was the Tampen Link hot tap in 2008. The hot tap cutting operation itself was performed without the use of divers; however, the preparatory works including hyperbaric welding of the hot tap tee was performed with saturation divers. The world’s deepest hot tap operations on a pressurized pipeline were performed on the Ormen Lange field in the Norwegian Sea in August 2009. Two Hot Taps were conducted in a water depth of 860 meters on pre-installed tees. The development of the Pipeline Repair System Remote Hot Tap equipment is the result of targeted research and development effort and extensive qualification work over many years. The Retrofit Tee remote installation, welding and cutting equipment has now been employed as part of a production installation: the Åsgard Subsea Compression project to extend the Åsgard gas-field lifetime. This paper describes the dry hyperbaric GMA weld procedure development and qualification performed in the laboratory, using the Corrosion Resistant Alloy consumable filler material Alloy 59, for the Remote Hot Tapping application using the Retrofit Tee. Specific attention was paid to areas of concern prior to performing the formal Weld Procedure Qualification work, particularly with regard to the effects of moisture and temperature upon the resultant weld quality. Weld procedures developed in the laboratory were successfully tested subsea in representative environments using the Remote Tee Welding Tool (RTWT) equipment in the Sognefjord, Norway, with offshore tests performed at 265 and 350msw in 2011. Further tests were performed in 2012 at 265msw and in the Retrofit Tee itself at 316msw in the Nedstrandfjord. The hyperbaric GMA weld procedures have now been applied for the production application for the Åsgard Subsea Compression project, with the installation of a Retrofit Tee, associated valve module and gooseneck spool to enable a cost-effective modification to the existing pipeline network without interfering with ongoing production. The Retrofit Tee will be connected with a Subsea Compressor station to extend the gas-field lifetime. This milestone represents the world’s first application of diverless dry hyperbaric GMA welding for a subsea production application.


Water ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 3573
Author(s):  
Hana D. Dawoud ◽  
Haleema Saleem ◽  
Nasser Abdullah Alnuaimi ◽  
Syed Javaid Zaidi

Qatar is one of the major natural gas (NG) producing countries, which has the world’s third-largest NG reserves besides the largest supplier of liquefied natural gas (LNG). Since the produced water (PW) generated in the oil and gas industry is considered as the largest waste stream, cost-effective PW management becomes fundamentally essential. The oil/gas industries in Qatar produce large amounts of PW daily, hence the key challenges facing these industries reducing the volume of PW injected in disposal wells by a level of 50% for ensuring the long-term sustainability of the reservoir. Moreover, it is important to study the characteristics of PW to determine the appropriate method to treat it and then use it for various applications such as irrigation, or dispose of it without harming the environment. This review paper targets to highlight the generation of PW in Qatar, as well as discuss the characteristics of chemical, physical, and biological treatment techniques in detail. These processes and methods discussed are not only applied by Qatari companies, but also by other companies associated or in collaboration with those in Qatar. Finally, case studies from different companies in Qatar and the challenges of treating the PW are discussed. From the different studies analyzed, various techniques as well as sequencing of different techniques were noted to be employed for the effective treatment of PW.


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