New Frontienrs in Pipeline Pressure Isolation: Non-Invasive, Without De-Pressurizing, Production Loss or Flow Interruption

Author(s):  
Rush Selden ◽  
Mark Sim

There are several methods for pressure isolating pipelines. Along with hot tapping and stopple and freeze plugging, there is another common method known as remote controlled (tether-less) pipeline plugging, whose use is increasing — both offshore and onshore. This paper will review piggable tether-less plugging technology, provided by TDW Offshore Services using the SmartPlug™, and case histories whereby a bi-directionally piggable, remotely actuated (tether-less) plug is deployed to allow pipeline operators to perform repair work, modifications, or tie-ins on pipeline systems without interrupting production in the remaining part of the pipeline system, i.e., while operating live and at production pressure. Specifically this paper will address two new technologies: First, allowing high pressure isolation of thin wall pipe, and second, of spiral wound pipe, both without welding, tapping or leaving any trace of the fact that an isolation occurred. Some advantages of tether-less plugging technology are: • Plugging tools have higher pressure containment capacity than other plugging methods, typically up to 3,000 psi. • Bi-directionally piggable, able to negotiate as small as 1.5D bends, operated and monitored entirely via remote control (tether-less through-wall control and communication system). • Compared to hot tapping, welding a fitting on the pipeline is not required, and no need to hot tap (drill) into the pipeline, no future leak path and no issues regarding cuttings or coupon. This latest frontier of pressure isolation allows for plugging tools that are fail-safe (the higher the differential pressure the harder they set) with zero leakage tolerance. They can be configured for job specific requirements such as double or single block, and can allow for hydrotesting the completed work. The most important advantage is that they eliminate the time needed and lost production cost of displacing pipeline product, flaring, depressurizing, emptying the line, and re-commissioning the line. In addition, specifically this paper will address the latest technology advances allowing high pressure isolation of thin wall (8mm/0.32 inch) spiral wound pipe using external pressure reinforcement clamps over the pressure isolation tool during an onshore project on a 24″ methane gas pipeline. During the isolation, a portion of the upstream pipeline was removed and replaced while the entire pipeline downstream of the pressure isolation remained under full operating pressure, thus requiring no loss of production from downstream assets during the repair. Once complete the tools were released and pigged from the line, leaving no holes, no welds, no future leak path and no trace that any event occurred on the pipeline in that location.

Author(s):  
Gunnar Staurland ◽  
Morten Aamodt

Norwegian waters have been a main arena for development of subsea pipeline technology over the last 25 year. The gas transportation systems from Norway to continental Europe comprise the largest and longest sub sea pipelines in the world. Codes traditionally require a pipeline to be designed with a uniform design pressure between stations with overpressure protection capabilities. However, the downstream part of a very long gas transmission pipeline may, after commissioning, rarely, if ever, see pressures near the pressure at the upstream end. There is, therefore, a potential for cost reduction and capacity improvement if two, or several, sections of different design pressure could be used without having to implement sub sea pressure regulation and overpressure protection facilities at the point of transition between the different sections of design pressure. In determining the lower design pressure the shutdown of the pipeline outlet facilities, at any point in time allowing for a practicable, achievable delay for closure of the upstream inlet valve has to be taken into account. The settle out pressure in a “normal” shut-in situation shall then not exceed the lower design pressure. In addition, deep water pipelines are often designed to withstand buckling due to bending and external pressure during installation, and may therefore locally tolerate a much higher internal pressure than the pipeline was designed for. Transmission pipelines crossing deepwater areas may therefore be designed for two or more operating pressures along the pipeline, thereby optimizing the cost. Even more important, for already existing pipelines, the capacity may be significantly increased by utilizing the upstream heavy wall sections. The operating pressure range for a long offshore gas transmission pipeline is very wide compared to an onshore line, typically between an upstream pressure of 150–250 bar, and a downstream pressure of 60 to 80 bar over a distance of several hundred kilometers. It may take hours to notice the closure of a downstream valve on the upstream pressure. Unless the pipeline is extensively packed, it is obvious that the pressure drop along the pipeline may be taken into account by allowing a lower design pressure for downstream part than for the upstream part. Thereby, the investment cost can be reduced. This paper describes the principles of designing a pipeline system divided into sections of different design pressures from a hydraulic point of view. The basis is the offshore standard for designing submarine pipeline systems, DNV OS-F101. The focusing will be on improvements in transportation efficiency, cost reductions and operational issues.


Antioxidants ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 54
Author(s):  
Monika Mieszczakowska-Frąc ◽  
Karolina Celejewska ◽  
Witold Płocharski

Nowadays, thermal treatments are used for extending the shelf-life of vegetable and fruit products by inactivating microorganisms and enzymes. On the other hand, heat treatments often induce undesirable changes in the quality of the final product, e.g., losses of nutrients, color alterations, changes in flavor, and smell. Therefore, the food industry is opening up to new technologies that are less aggressive than thermal treatment to avoid the negative effects of thermal pasteurization. Non-thermal processing technologies have been developed during the last decades as an alternative to thermal food preservation. Processing changes the structure of fruit and vegetables, and hence the bioavailability of the nutrients contained in them. In this review, special attention has been devoted to the effects of modern technologies of fruit and vegetable processing, such as minimal processing (MPFV), high-pressure processing (HPP), high-pressure homogenization (HPH), ultrasounds (US), pulsed electric fields (PEF), on the stability and bioavailability of vitamin C.


1987 ◽  
Vol 20 (1) ◽  
pp. 18-25
Author(s):  
P Gilbert

The transmission and distribution system operated by British Gas plc is the largest integrated pipeline system in Europe. The whole system comprises a national transmission system which carries gas from five terminals to the twelve gas regions. Each region in turn carries the gas through a regional transmission system into a distribution grid and thence onto its customers. The national, regional and distribution system all present the instrument engineer with different technical challenges because of the way in which they have been built and are operated, however, it is simplest to characterise them by their process conditions. The operating pressure is highest in the national transmission system being up to 75 bar, in the regional transmission system the pressure is usually less than 37 bar, and in the distribution grid it is less than 7 bar. In general, the pipe diameters decrease from the national system downwards, and the measured flowrates are lowest in the distribution grids. This paper is concerned only with instrumentation on the national transmission system. The discussion will cover current technology which is typical of that being installed at present, and concentrates on the more commonly found instrumentation. The paper begins with a brief history of development of the national transmission system and a description of how it is operated. This is followed by a discussion on the application of computers to the control of unmanned installations. A section concerning the measurement of pressure and its application to the control of the system comes next. The main part of the paper contains an analysis of high accuracy flowmetering and the paper concludes with some comments on developments in instrumentation and their application to changing operation of the national transmission system.


Author(s):  
Shanzhong Duan ◽  
Mutasim E. Gamal

This paper presents a new method for computer-aided modeling and analyzing of pulsation dampeners used in fluid power systems for vibration reduction. The pulsation dampeners are widely used in various fluid power systems to reduce vibration induced by power pumps. The vibration induced by power pumps in fluid systems may be severe enough to cause the damage of components in pipelines if a pulsation dampener is not installed. However, the current methods used in industries for the design and analysis of the dampeners are manually experience-orientated procedures. They are not adaptable to new technologies. The new modeling method will efficiently automate and improve the current modeling and analysis procedure of various pulsation dampeners with a minimum user effort. The proposed method is a result of utilizing the analogy between electrical circuits and hydraulic circuits. In the new method, a spherical pulsation dampener can be equivalent to a lumped hydraulic circuit installed in a distributed fluid pipeline system. The new method has been developed from the authors’ previous work of an impedance-based model in which only the effect of capacitance and inductance was considered without fluid resistance. In reality, the influence of fluid resistance is significant. This paper will take fluid resistance into considerations and form a resistance-impedance-based model.


Author(s):  
Peter Song ◽  
Doug Lawrence ◽  
Sean Keane ◽  
Scott Ironside ◽  
Aaron Sutton

Liquids pipelines undergo pressure cycling as part of normal operations. The source of these fluctuations can be complex, but can include line start-stop during normal pipeline operations, batch pigs by-passing pump stations, product injection or delivery, and unexpected line shut-down events. One of the factors that govern potential growth of flaws by pressure cycle induced fatigue is operational pressure cycles. The severity of these pressure cycles can affect both the need and timing for an integrity assessment. A Pressure Cycling Monitoring (PCM) program was initiated at Enbridge Pipelines Inc. (Enbridge) to monitor the Pressure Cycling Severity (PCS) change with time during line operations. The PCM program has many purposes, but primary focus is to ensure the continued validity of the integrity assessment interval and for early identification of notable changes in operations resulting in fatigue damage. In conducting the PCM program, an estimated fatigue life based on one month or one quarter period of operations is plotted on the PCM graph. The estimated fatigue life is obtained by conducting fatigue analysis using Paris Law equation, a flaw with dimensions proportional to the pipe wall thickness and the outer diameter, and the operating pressure data queried from Enbridge SCADA system. This standardized estimated fatigue life calculation is a measure of the PCS. Trends in PCS overtime can potentially indicate the crack threat susceptibility the integrity assessment interval should be updated. Two examples observed on pipeline segments within Enbridge pipeline system are provided that show the PCS change over time. Conclusions are drawn for the PCM program thereafter.


2021 ◽  
Author(s):  
Chris Alexander ◽  
Richard Kania ◽  
Salem Talbi ◽  
Jon Rickert
Keyword(s):  

2014 ◽  
Vol 70 (a1) ◽  
pp. C157-C157
Author(s):  
Claire Hobday ◽  
Stephen Moggach ◽  
Carole Morrison ◽  
Tina Duren ◽  
Ross Forgan

Metal-organic frameworks (MOFs) are a well-studied class of porous materials with the potential to be used in many applications such as gas storage and catalysis.[1] UiO-67 (UiO = University of Oslo), a MOF built from zirconium oxide units connected with 4,4-biphenyldicarboxylate (BDC) linkers, forms a face centred cubic structure. Zirconium has a high affinity towards oxygen ligands making these bridges very strong, resulting in UiO-based MOFs having high chemical and thermal stability compared to other MOF structures. Moreover, UiO-67 has become popular in engineering studies due to its high mechanical stability.[2] Using high pressure x-ray crystallography we can exert MOFs to GPa pressures, experimentally exploring the mechanical stability of MOFs to external pressure. By immersing the crystal in a hydrostatic medium, pressure is applied evenly to the crystal. On surrounding a porous MOF with a hydrostatic medium composed of small molecules (e.g. methanol), the medium can penetrate the MOF, resulting in medium-dependant compression. On compressing MOF-5 (Zn4O(BDC)3) using diethylformamide as a penetrating medium, the framework was shown to have an increased resistance to compression, becoming amorphous several orders of magnitude higher in pressure than observed on grinding the sample.[3] Here we present a high-pressure x-ray diffraction study on the UiO-based MOF UiO-67, and several new synthesised derivatives built from same metal node but with altered organic linkers, allowing us to study in a systematic way, the mechanical stability of the MOF, and its pressure dependence on both the linker, and pressure medium.


Author(s):  
Dale Millward

Effective pipeline design and regular maintenance can assist in prolonging the lifespan of subsea pipelines, however the presence of marine vessels can significantly increase the risk of pipeline damage from anchor hazards. As noted in the Health and Safety Executive – Guideline for Pipeline Operators on Pipeline Anchor Hazards 2009. “Anchor hazards can pose a significant threat to pipeline integrity. The consequences of damage to a pipeline could include loss of life, injury, fire, explosion, loss of buoyancy around a vessel and major pollution”. This paper will describe state of the art pipeline isolation tooling that enables safe modification of pressurised subsea pipelines. Double Block and Bleed (DBB) isolation tools have been utilised to greatly reduce downtime, increase safety and maximise unplanned maintenance, providing cost-effective solutions to the end user. High integrity isolation methods, in compliance with international subsea system intervention and isolation guidelines (IMCA D 044 / IMCA D 006), that enable piggable and unpiggable pipeline systems to be isolated before any breaking of containment, will also be explained. This paper will discuss subsea pipeline damage scenarios and repair options available to ensure a safe isolation of the pipeline and contents in the event of an incident DNV GL type approved isolation technology enables the installation of a fail-safe, DBB isolation in the event of a midline defect. The paper will conclude with case studies highlighting challenging subsea pipeline repair scenarios successfully executed, without depressurising the entire pipeline system, and in some cases without shutting down or interrupting production.


Author(s):  
Jerry Rau ◽  
Mike Kirkwood

Pressure testing of pipelines has been around in some form or another since the 1950s1–14. In its earliest form, operators used inert gases such as Nitrogen or even air to test for pipeline integrity. However, with the significant increases in pipeline pressures and inherent safety issues with a pressurized gas, the switch to using water happened in the late 1960’s15–17. Hydrostatic tests (referred to as hydrotests) have been used since then to set and reset the Maximum Allowable Operating Pressure (MAOP) for pipelines but as other technologies develop and gain acceptance will hydrotesting still play a key role in pipeline integrity in the years ahead? Currently, hydrotesting is a topic for the impending US Pipeline and Hazardous Materials Safety Administration’s (PHMSA) Proposed New Rule Making (PNRM)18. Under the NPRM, hydrotesting is required to verify MAOP on pre-1970s US “grandfathered” pipelines, as well as on pipelines of any age with incomplete or missing testing record and include a high level test with a “spike” in pressure. But hydrotesting may not be the only method. Alternative methods and new technologies — used alone or used in combination with hydrotesting — may help provide a more comprehensive way for operators to identify and address potential problems before they become a significant threat. This paper explores both sides of the argument. Before In-Line Inspection (ILI) technology was even available, hydrotesting was the absolute means of the proof of integrity. However, hydrotesting is under scrutiny for many reasons that this paper explores. ILI was introduced in the 1960’s with the first commercially available Magnetic Flux Leakage (MFL) tools that presented the industry with an alternative. Currently there are a huge array of available technologies on an ILI tool and so is the role of the hydrotest over? The paper looks at the benefits of the hydrotest and these are presented and balanced against available ILI technology. Furthermore, as pipelines are being developed in even more harsh environments such as deepwater developments, the actual logistics of performing a hydrotest become more challenging. The paper will also look at both applications onshore and offshore where regulators have accepted waivers to a hydrotest using alternative methods of proving integrity. The paper concludes with the current use and needs for hydrotesting, the regulatory viewpoint, the alternatives and also what the future developments need to focus on and how technology may be improved to provide at least a supplement if not a replacement to this means of integrity assurance.


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