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PIPELINE TECHNOLOGY JOURNAL 3 EDITORIAL ptj - moving forward with new services and a new design You have certainly noticed it already: the ptj now looks different than before. This is the result of an extensive improvement process to which we have com- mitted ourselves in order to provide the international pipeline community with even better content. Of course, the appearance plays only the smallest part, even if it is the most conspicuous at first glance. The ptj has received a new website which offers more extensive added val- ue. All important pipeline news around the world are clearly and appealingly presented on our homepage. You, the reader, can filter according to your own criteria. Whether industry news or political developments: With just a few mouse clicks, you receive the reports that are really relevant to you. Admir Celovic Director Publications EITEP Institute This also applies to our extensive collection of articles with which we provide pipeline experts from all over the world with details on the latest technical innovations. The abstracts are now all digitized and tagged, enabling you to quickly and accurately retrieve the content that is of par- ticular interest to you as a pipeline professional. We are also constantly improving our newsletter: With the help of a series of international partnerships, we will be able to process the most important business events from the pipeline world even better and more purposefully for you. With ptj, you have an information hub that you should keep an eye on regularly in order to stay up to date. So check out the relaunched ptj brand and let us know your thoughts. We will be happy to further improve our services: firstname.lastname@example.org Also, do not forget to register for the upcoming Pipeline Technology Conference (ptc) in Berlin, Germany, taking place from 30th March to 2nd April 2020. As Europe’s leading pipeline conference and exhibition, the ptc pro- vides you with the attractive opportunity to inform yourself about state of the art pipeline technologies. More than 80 pipeline operators from around the world will be present, making ptc to a central hub for business opportunities. Be a part of this success story: www.pipeline-conference.com Yours, > Admir Celovic, Director Publications, EITEP Institute
4 PIPELINE TECHNOLOGY JOURNAL THIS ISSUE’S COMPLETE CONTENT OCTOBER 2019 / ISSUE 4 Quality Process, Digitalization of Pipeline Contruction Léna Muscillo LogIC Advanced Onshore Pipeline Anchoring Alternatives Adham Ghali, Elie Dib INTECSEA UK Ltd. 6 10 River crossing and water crossing survey by airborne bathymetric laser scanning Rupert Kellerbauer gispc Current View of Design and Evaluation of Sulfur Pipelines Dr. Kai Bauerbach, Dr. Paschalis Grammenoudis MMEC Mannesmann GmbH 18 24 Company Directory Page 34 Pipeline Technology Journal - ptj @pipelinejournal www.pipeline-journal.net Pipeline.Technology.Conference ptc Preview 32 Event Calendar 39
Quality Process, Digitalization of Pipeline Construction Léna Muscillo > LogIC Abstract Pressurized fluid transport structures are subject to regulatory obligations for which the system operators must ensure compliance with the administration. In order to meet the obligations and ensure safety of the networks, in addition to the regulatory documents, the managers demand from the holders of laying contracts, the provision of documents allows attesting that the pipelines were made in accordance with professional standards and contractual requirements (plans, operating modes, self-checks, trial).. As a quality service provider for the managers and the holders of laying markets on the main gas works built since 2013 in France, LogIC experience feedback has allowed us to note that management and quality assurance processes implemented on these worksites could be optimized. As a result, we decided to digitalize and dematerial- ize building quality management by developing a connected mobile application. This application installed on PDAs and Touch Pad (Honeywell) allows access to the field, to all the data of a pipe or a welding thanks to the individual identification by bar code labels (examples: ready welding for coating, bending pipe). The use of this application also makes it possible to integrate all the construction data into the database from the site (no more paper, no more document repositories at the end of the day). From a quality management point of view, the self-checks and trials activity reports are automatically generated, the production monitoring is instantaneous, the welding logs are fed automatically and instantaneously. These devel- opments make it possible to ensure the compliance of site activities, to access all construction data directly from the field, to make the feedback of information reliable, to secure sensitive data, to reduce worksite / office trips, to reduce paper in this air of technological mutation, this application is obvious! It’s LogIC
RESEARCH / DEVELOPMENT / TECHNOLOGY PIPELINE TECHNOLOGY JOURNAL 7 1. CONTEXT Nowadays, in pipeline construction, important human re- sources are set in place to provide the necessary elements in order to guarantee works conformity. • • Fits all fluids Fits all languages HOW Q.C.M. WORKS? However, the management remains handwritten for the construction site part, followed by quality control and computer transcription. This current quality-process organization is not efficient, that’s why we devel- oped a quality management turnkey tool, Q.C.M. Our experience permits us to know that the key of success, for this kind of project, is based on people. In addition to knowledge of networks managers requirements, we devel- oped this tool with a human point of view to improve working conditions and performances. Each is actor of the success, using the best, every- body can give their best. Q.C.M. permit our customers to guarantee the conformity of their construction improving team work conditions, optimizing quality control tasks efficiency and reducing papers and car rides. 2. Q.C.M. TOOL – THE EFFICIENT WAY TO BE EFFECTIVE It’s composed of a mobile applica- tion associated with label readers and bar code labels, glued to the pipes and welds. This tool is used from pipe’s re- ception (or manufacturing) to the pressure test, by construction team, quality control center and project management, on the construction site and at the office. Figure 1: How Q.C.M. works 3. THE APPLICATION This application is set on PDAs and Touch Pad (Honeywell) and allows an access to the field, to data pipe or a welding thanks to the individual identification by a bar code label (examples: ready welding for coating, bending pipe). • Fits all regulations REQUIRED INPUT DATA Pipe packing list from supplier – Excel file Pre-bending book – Excel file • • • Machines used on the project – Hand grabbing in the app • Authorization and access of the responsible • Project technical data (tolerance value, compliance rules, specific requirements) – Hand grabbing in the app
8 PIPELINE TECHNOLOGY JOURNAL RESEARCH / DEVELOPMENT / TECHNOLOGY THE SELF-CHECK The self-checks need to be provided to the customer within 24 hours after operations. They were all digitalized and, thanks to the Q.C.M. quality system management, are au- tomatically generated by the data entered by the operators on the field. Application adaptabilities allows us to create, digitalize and integrate other documents in addition to those cur- rently developed. This automatic data transfer allows the yard team leaders to provide, in real time, the daily advancements toward the quality cell without going back to the project office. Sensi- tive to safety, we wanted to reduce the number of car trips which are an important cause of accident. By eliminating hand notes, retranscription on computer, impressions and scans, managers can focus on their core business and specialities. THE WELDING BOO It’s the pipeline construction’s reference document. It lists all elements that constitute the structure (pipes N°, welds N°, welders’ identification, materials used, non-de- structive test reports, etc). This document is essential for the success of pressure tests before the pipeline is put into service. Our app allows to secure the completeness of this docu- ment by integrating in real time the necessary information identified on the field. ANOMALIES REPORT The application compares the data received with those expected or imposed by the regulations. If an anomaly is detected, a report is automatically sent, by email, to the concerned managers. The app got an area dedicated to anomalies where managers can learn more about the non-conformity and treat it easily, in real time. Here is all the benefit to introduce Q.C.M. on a pipeline construction site, saving time. An important stream of data is generated at the same time but from different place and specific activities. Having a general point of view, in real time, on activities progress allows an efficient management of the anomalies and time in general. 4. BARCODES & LABELS Two kind of barcodes are used: • White ones for pipes Yellow ones for welds • Each barcode is unique and printed in 3 copies, or more, depending on the project we are working on. Yellow labels are glued near to the weld, the white ones are glued on, or inside, the pipe. Labels are made in Polypropylene material. It provides excellent reading and adhesive performance on a wide variety of surfaces including non-polar, slightly rough and curved substrates. It also resists against all climatic condi- tions (Sun, rain, snow, cold/hot, etc.). 5. SCANNERS & PRINTERS Figure 2: Honeywell scanner with the LogIC application We use two kinds of scanners, CT50 and EDA70, and one printer, PC43T.
RESEARCH / DEVELOPMENT / TECHNOLOGY PIPELINE TECHNOLOGY JOURNAL 9 This professional equipment offers a great autonomy, is resistant and very efficient in a hard environment such as on a construction yard (rain, cold/hot, fall, etc). • Anticipate and secure pressure tests • • Secure and stock all project data Increase the safety level of the yard Our partnership with HONEYWELL guarantees reactivity, professionalism and availability across the world. 6. BENEFITS • Use an efficient quality management system • Optimize construction times and costs • Allows production tracking • • • • • Allow the actors of the yard to focus on their core Remove most of the possible mistakes Edit automatically reports and self-checks Fill automatically the welding book Follow in real time the progress of the project business Author Léna Muscillo LogIC Président-directeur général Lena.email@example.com Pipeline Technology Journal Join 30,000 verified recipients and get the latest news, reports and comments to pipeline related topics, including political developments and company-specific information. Register for free! Stay up-to-date with the ptj - newsletter
Advanced Onshore Pipeline Anchoring Alternatives Adham Ghali, Elie Dib > INTECSEA UK Ltd. Abstract Pipelines may observe significant axial displacement or force at the ends that tie-in with connected equipment and/ or facilities. These axial forces are mainly driven by pipe size, temperature, pressure, length and surrounding soils or supports, and can have devastating effects on connecting facilities if not properly accommodated in the design. The most common approach to address this issue is deployment of concrete anchor blocks just before tie-in loca- tions to achieve full isolation between pipelines and other connected systems. This leads to an increased cost of construction as well as handling and installation of massive concrete tonnage on a soil foundation of potentially high uncertainty, therefore proving to be economically unattractive. With the expansion of fields and processing facilities, including an anchor may also be physically challenging due to space restrictions. This paper covers assessments of several pipeline case studies that range from 6” to 18” Nominal Pipe Size (NPS) interacting with the major soil categories clay and sand for design temperatures up to 250°C. The assessments show that for a significant number of cases the presence of an anchor is an over-design of the pipeline system, leading to unnecessary costs and potentially more complicated logistics. Studied cases were analysed using the non-linear Finite Element Analysis (FEA) algorithm of the Abaqus software suite with controlled end displacements. The work also establishes a case envelope to which the outcomes of this study will be applicable where pipeline conditions lie within the boundaries of the studied cases.
RESEARCH / DEVELOPMENT / TECHNOLOGY PIPELINE TECHNOLOGY JOURNAL 11 1. INTRODUCTION Pipelines, particularly steel ones, can observe significant axial displacement or force at straight ends that tie-in with connected equipment and facilities. This is mainly driven by temperature, pipe size, straight length, surrounding soils, supports, and pressure. Depending on the pipeline configuration, the axial effect is conventionally quantified by either calculating the fully restrained theoretical force at the pipeline end, or fully converting the force to end movements in a theoretically unrestrained pipe. Depending on functional requirements and operator spec- ifications, the generated axial forces and movements need to be within the allowable limits of connecting utilities, such as piping, or isolated using an engineered solution. Recent advances in seismic imaging and reservoir map- ping technologies (Halsey, 2016) have enabled production from deeper reservoirs at higher pressures and tempera- tures. This poses new challenges to production and trans- port infrastructure design, which are sometimes technically prohibitive using conventional engineering. This paper discusses the current issues facing pipeline end interface design under elevated operating conditions and presents a Finite Element (FE) based approach to optimize, or eliminate, pipeline anchoring requirements. 2. TECHNICAL CHALLENGE The search for new, production feasible, hydrocarbon reser- voirs is driving drilling deeper wells (DeBruijn, et al., 2008), and with temperatures increasing proportionately with depth in the order of 15 to 30 degC per 1km of depth (Satter & Iqbal, 2016) this translates to more challenging design conditions. unrestrained or not considered in the design. The conventional approach to resist axial forces is by utilizing anchors at the interface (Bahadori, 2017). Some Engineering Standards for designing concrete blocks also define the allowable limits for pipeline end displacements (Saudi Aramco, 2005). For lower flowing temperatures the required anchor capaci- ties are in the order of 2000 to 3000 kN, typically yielding an anchorage footprint of 5x5m, with typical depths of between 4 and 5 m. However, anchor capacities for larger pipes with challenging design conditions can reach 5000 to 9000 kN, with much larger footprints (16x16m) (SA_Wa- ter, 2007), which is demonstrated in Section 4. The construction of such anchors, particularly in ma- ture fields with safety and access complexities, leads to excessive soil resistance requirements and becomes near prohibitive. Moreover, supporting sheet piles may be required if many anchors are required within a congested field (Thorley & Atkinson, 1994). Notably, (Ghdaib, et al., 2011) conducted a field monitoring study on a pipeline anchor block system indicated that the installed anchor block sizes could be reduced based on the obtained strain and stress response data. 3. AVAILABLE SOLUTIONS An investigation of available alternatives to mitigate the large expansions and forces encountered at pipeline ends was driven by the challenges outlined in Section 2 with the aim of reducing anchor size or eliminating the anchor requirement. One of the options to reduce the end forces and the anchor block footprint is combining gravity based anchors with a form of piling, such as sheet piling as shown in Figure 1. Concurrently, pipeline technologies have de- veloped and enabled an increase in operating pressures from 2 to 120 bar between the years 1910 and 2000 (Hopkins, 2007). More recently, the use of thermal recovery techniques, even in shallower layers, has dramatically increased production temperatures (Belani & Orr, 2008). It follows that requests for pipelines designed to temperatures in the order of 70 to 100 degC for production from high-temperature wells (Mahmoud, 2017), are becoming more com- mon. Pipelines designed to such conditions could generate sufficient axial force to cause damage to connecting infrastructure if left Figure 1: Pipeline Ends - Anchor Blocks
12 PIPELINE TECHNOLOGY JOURNAL RESEARCH / DEVELOPMENT / TECHNOLOGY Route optimization is also a common option, and although primarily utilizing in-line bends to minimize route obstruc- tions and rough terrain, it is sometimes aimed at minimiz- ing straight pipe lengths to reduce high load and stress concentration areas as indicated in Figure 2. resulting pipeline end expansion. That formed the basis for concrete block sizing based on lateral earth pressure theory (Das, 2014), which covers sta- bility, sliding, overturning and base load checks on anchor design. Below is a summary of the concrete block sizes required. Figure 2: Pipeline Route - Minimizing Straights Another alternative is introducing L, Z or U bends at the pipeline end to accommodate the incoming forces and expansions as shown in Figure 3. 4. CONVENTIONAL APPROACH The typical approach to designing tie-in interfaces is obtaining analytical estimates for end forces and displace- ments using principal equations. This is widely considered a quick method providing conservative results. This was performed for the investigated cases and ASME B31.8 (ASME, 2016) equations for calculating restrained pipe axial forces were consulted. End displacements were calculated using the difference between the driving pipeline strain due to temperature and pressure in the face of resisting soil friction to arrive at the Figure 4: Concrete Block Requirements Figure 3: Pipeline Ends - Bend Configurations
5. ADVANCED APPROACH In recent years the increased availability and efficiency of FE based Analysis and computational power have enabled detailed capture of previously over-estimated loads by con- sidering geometrical, soil and material non-linearities. The advanced approach is based on utilizing FE tools to capture the property and geometry variations not captured in the conventional approach presented in Section 5. Additionally, incremental FE analysis is useful in defining the workable limits of a proposed configuration, including the maximum acceptable temperature or pressure. 5.1. NON-LINEAR SOLUTION The FE based Abaqus solver efficiently estimates forces and displacements of buried pipelines approaching above ground tie-ins and simulates pipe and soil 3D behaviour. Contrary to the conventional single system linear solution, the non-linear Abaqus solver is based on incremental loading and equilibrium, this enables the simulation of true loading scenarios as they would occur in real-life. 5.2. COUPLED MODELLING A key input for anchor block force balance is the incom- ing loads on both sides, the above ground and the buried side of the anchor location. Conventionally, this would be independently calculated for each side and conservatively approximated, resulting in over-estimated above ground displacements and exaggerated the interface loads. RESEARCH / DEVELOPMENT / TECHNOLOGY PIPELINE TECHNOLOGY JOURNAL 13 derstanding of the integrated system during design and ultimately helps reduce, or eliminate, approximations at interfaces and achieve maximum design optimization with minimum construction spreads. Figure 5: Coupled Pipeline/Piping Model 5.3. SAMPLE CASE STUDY To demonstrate the benefits of advanced analysis captur- ing realistic interface loads when utilized alongside simple geometry, the simplified Z-bend pipeline end configuration Figure 6 was selected as a representative sample case. The analysed cases covered buried pipe sizes between 6” and 18” covering 2000m of straight length for diame- ter-to-thickness ratios 10 and 25. Optimization outcomes were measured by comparing the resulting forces and displacements to the analytical esti- mates as detailed in Section 6. This can be optimized through coupled modelling, which incorporates the stiffness of connected piping/utilities into the modelled system as indicated in Figure 5. The established model continuity develops a global un- For this study, soil springs used in the analysis represented cases of typical sand and typical clay to cover both cohe- sionless and cohesive soil types. On a typical assessment, soil properties are obtained from geotechnical survey interpretations transformed into workable analysis inputs Figure 6: Selected Z-Bend Configuration
14 PIPELINE TECHNOLOGY JOURNAL RESEARCH / DEVELOPMENT / TECHNOLOGY Figure 7: Sample End Force Comparison - 14” Pipe based on PRCI (Douglas G. Honegger, 2004) soil models for axial, lateral, vertical bearing and vertical uplift resis- tances. 6. COMPARATIVE ASSESSMENT 6.1. RESULTS The investigation included a comparative study of the resulting forces and displacements from the conventional approach and the advanced approach. The following out- puts comprise the values used in the comparison for the studied load cases: • Full force feed-in – This is the fully restrained axial force based on standard (ASME, 2016) calculations. It is the highest axial force possible for each considered case. • Optimized force feed-in – This is the FE based axial force at the end of the straight pipeline segment, immediately before the Z-bend. This represents the axial force observed at the pipeline end with the intro- duced end optimization. Figure 7 indicates the forces when compared for a sample case. • • A sample force profile indicating the fully restrained • force feed-in and the optimized force feed-in is shown in Figure 8. Full movement feed-in – This is the FE based displace- ment at the end of the straight pipeline segment, im- mediately before the Z-bend. It is the largest achieved end displacement for each modelled case • Optimized movement feed-in – These are the con- ditions at the end of the Z- bend investigated in this study, they represent the partially restrained conditions only accurately captured using FE based analysis. Figure 9 indicates the displacements when compared for a sample case. A summary of the results for non-cohesive soils indicating reduction is shown in Figure 10. Figure 8: Sample Force Profile Register for free! Stay up-to-date with the ptj - newsletter
RESEARCH / DEVELOPMENT / TECHNOLOGY PIPELINE TECHNOLOGY JOURNAL 15 Figure 9: Sample End Movement Comparison - 14” Pipe Figure 10: Force, Expansion and Footprint Reduction - Non-cohesive soils 6.2. DISCUSSION 6.2.1. END FORCE AND DISPLACEMENT Upon reviewing the resulting forces and displacements, the assessment indicates effective axial force values of 30% or less of the conventional fully restrained axial force and 60% or more reduction in end displacements for the analysed cases. It is clear from the results that the fully restrained axial loading is significantly higher than the partially restrained force at the anchor location. This is demonstrated in the presented force reduction in Figure 11. The conventional approach of conservative analytical esti- mates of pipeline end force and displacement offers a clear split of scope between different engineering disciplines utilizing interface loads in their design, it also facilitates in- dependent discipline variations and progress measurement. However, based on the technical challenges presented in Section 2 and the results presented in this Section, this approach sometimes becomes uneconomic and unrealistic due to the pipeline anchoring occupying too much large real estate and sometimes introducing pipe misalignments. The advanced approach, on the other hand, offers a ver- satile approach to addressing the loads at pipeline end connections, which depends on accurately capturing the interface loads and stiffnesses. Although it does not offer complete isolation, advanced computation of interface loads enables the design to match the exact loading requirements. Figure 11: End Force and Displacement
16 PIPELINE TECHNOLOGY JOURNAL RESEARCH / DEVELOPMENT / TECHNOLOGY 6.2.2. SOLUTION FOOTPRINT This indicates significant technical and economic advantag- es of utilizing model continuity for pipeline ends design. Using the conventional approach, isolation is achieved using the anchor footprint, explained in Figure 7, which incrementally increases with the increase in pipe size and diameter-to-thickness ratio. Using the advanced approach shows the investigated Z-bend configuration offers minimal footprint increase with pipe size to achieve the desired reduction in forces and displacements. This results in optimized solution footprint for all investigated pipe sizes with diameter-to-thickness ratio of 10, and an optimized footprint for 12” and larger pipe sizes for diameter-to-thickness ratio of 25 as shown in Figure 12. 6.2.3. COUPLED MODELLING The concept of coupled modelling discussed in Section 5.2 was applied by the author extensively on project specific configurations, using both linear and non-linear solvers. A pilot comparison with the conventional independent ap- proach showed that coupled modelling reduced the translat- ed forces by more 90%. Moreover, the stress utilizations on the connected piping dropped by a full order of magnitude for thick wall pipes with diameter-to-thickness ratio of 9.5. 7. CONCLUSIONS This paper demonstrates a simple, technically feasible engi- neering approach to optimizing pipeline end configurations, end expansions and forces for the investigated cases. A sample case of Z-bend at the pipeline end is shown to reduce the axial force by 85% on average when compared to complete fixation achieved using anchor blocks, while maintaining axial displacement at less than 20% of the unrestrained pipeline configuration on average. The results show that the Z-bend can be an efficient and less environmentally invasive alternative than conventional anchor blocks for buried pipelines, with established reduc- tion in footprint for thick pipe sizes between 6” and 18”, and thin pipe sizes between 12” and 18”. Moreover, if anchoring is unavoidable, significant reductions can be achieved in anchor capacity requirements while still maintaining the purpose of the anchor by adopting the ad- vanced modelling approach discussed in this paper. Figure 12: Solution Footprint
RESEARCH / DEVELOPMENT / TECHNOLOGY PIPELINE TECHNOLOGY JOURNAL 17 Introducing connected piping/utilities for project specific configurations further added to the presented optimization as discussed in Section 6.2.3. It is therefore also concluded that coupled modelling of pipelines and connected piping/ utilities enables the design to accurately capture the forces and displacements from all system components. This optimization of the interaction loads between under- ground pipelines and the connected above-ground facilities realizes significant technical and economic benefits. 8. RECOMMENDATIONS AND FUTURE WORK Authors Adham Ghali INTECSEA UK Ltd. Senior Pipeline Engineer Adham.Ghali@intecsea.com Based on the results presented in this study, it is recom- mended that detailed investigation of engineered alter- natives to concrete anchor blocks is adopted as common practice within the pipe size envelope of 6in to 18in, with diameters ranging 10 to 25 times the thickness. Elie Dib INTECSEA UK Ltd. Chief Pipeline Engineer Elie.Dib@intecsea.com Additionally, a risk assessment of the assumptions is also recommended to complement this work with quantifiable probabilities and scenarios of failure to drive further re- duction in required sizes and, where feasible, eliminate the need for pipeline anchor blocks. ACKNOWLEDGEMENTS References The authors would like to express their sincere gratitude to Mikey Scott, INTECSEA UK Ltd., for his invaluable insight and expertise. The authors would also like to thank Thibaut Rawlings, Genesis Oil and Gas Consultants Ltd., and Juri Kaljusto, INTECSEA UK Ltd., for their valuable contribution to this study. 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. ASME, 2016. B31.8 - Gas Transmission and Distribution Piping Systems, s.l.: The American Society of Mechanical Engineers (ASME). Bahadori, A., 2017. Chapter 1 - Transportation Pipelines. In: Oil and Gas Pipelines and Piping Systems Design, Construction, Management, and Inspection. s.l.:Gulf Professional Publishing, pp. 1-27. Belani, A. & Orr, S., 2008. A Systematic Approach to Hostile Environments. Journal of Petroleum Technology, 60(07). Das, B. M., 2014. Principles of Foundation Engineering, 8th Edition. s.l.:Cengage Learning. DeBruijn, G. et al., 2008. High-Pressure, High Temperature Technologies. Oilfield Review, pp. 46-60. Douglas G. Honegger, D. J. N., 2004. PR-268-9823 - Guidelines for the Seismic Design and Assessment of Natural Gas and Liquid Hydrocarbon Pipelines, s.l.: Pipeline Research Council International (PRCI). Ghdaib, A. K. A. et al., 2011. Field Monitoring of an In-Service Thrust Anchor Block and Pipeline. SAUDI ARAMCO JOURNAL OF TECHNOLOGY. Halsey, T. C., 2016. Computational sciences in the upstream oil and gas industry. Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, 374(2078). Hopkins, P., 2007. PIPELINES: Past, Present, and Future. Sydney, Australia, s.n. Mahmoud, M. A., 2017. Pressure and Thermal Regimes and Systems in the Sedimentary Se- quence of Central and Eastern Saudi Arabia. In: Lithosphere Dynamics and Sedimentary Basins of the Arabian Plate and Surrounding Areas. s.l.:Springer, Cham, pp. 33 - 50. SA_Water, 2007. Guidelines for the design of Anchors and Thrust Blocks on Buried Pipelines with Unrestrained Flexible Joints and for the Anchorage of Pipes on Steep Grades, s.l.: South Australian Water Corporation. Satter, A. & Iqbal, G. M., 2016. Reservoir fluid properties. In: Reservoir Engineering - The Fundamentals, Simulation, and Management of Conventional and Unconventional Recoveries. s.l.:Elsevier, pp. 81-105. Saudi Aramco, 2005. SAES-L-440 - Anchors for Buried Pipelines, s.l.: Saudi Aramco - Onshore Structures Standards Committee. Thorley, A. R. D. & Atkinson, J. H., 1994. Guide to the Design of Thrust Blocks for buried Pressure Pipelines, London: Construction Industry Research and Information Association (CIRIA). 15th Pipeline Technology Conference Europe‘s leading pipeline conference and exhibition Pipeline T Conference 2010 SAVE THE DATE 30 March - 2 April 2020 Berlin, Germany
River crossing and water crossing survey by airborne bathymetric laser scanning - Case study TAG Rupert Kellerbauer > gispc - geographic information system & processing consulting Abstract Airborne bathymetric laser scanning delivers the same results as regular airborne laser scanning, but with one major difference, this technology is able to penetrate water. The technology has matured through the past years, mean- while it is used for the bathymetric survey of lakes, harbors, coastal shore lines and rivers. The Trans Austria Gasleitung (TAG) is a major part of the gas supply chain for central Europe, it consists of three and mostly parallel pipelines and five compressor stations, the diameters are from 36 to 42 inch and the operating pres- sure is up to 70 bar. The TAG leads from the Slovakian-Austrian border to the Austrian-Italian border and crosses Austria on a length of approx. 380 km, it is composed of approx. 1,140 km pipeline in total. Trans Austria Gasleitung GmbH, as operating company, has performed a bathymetric survey of 23 selected river crossings by airborne bathymetric laser scanning in 2017. The survey was part of several remote sensing services performed to monitor the situation at site and to update the base map data along the entire route of TAG, the river crossings are spread along TAG´s 380 km. The technology enables a totally new approach to perform bathymetric surveys for all kind of water crossings of pipelines, such as river crossings, landfalls and other kind of water crossings. It delivers more and better information in shorter time, compared to classical procedures like terrestrial survey or echo sounding. The right approach for the survey mission ensures the capturing of all required data.
RESEARCH / DEVELOPMENT / TECHNOLOGY PIPELINE TECHNOLOGY JOURNAL 19 1. TRANS AUSTRIA GASLEITUNG (TAG) 2. TECHNOLOGY & SETUP 1.1 TAG PIPELINE SYSTEM 2.1 TECHNOLOGY The TAG Pipeline System consists of three lines (TAG I, TAG II, TAG Loop II), five compressor stations, auxiliary equipment as well as two Entry Points and one Exit Point. The Pipeline leads from the Slovakian-Austrian border near Baumgarten an der March to the Austrian-Italian border near Arnoldstein covering a length of about 380 km and is composed of about 1,140 km pipelines with diameters ranging from 36 to 42 inches and a pressure of up to 70 bar. The total installed power of the compressor stations is approx. 480 MW. Airborne laser scanning is when a laser scanner, while at- tached to an aircraft during flight, creates a 3-D point cloud model of the landscape. (Wikipedia/ https://en.wikipedia. org/wiki/Lidar ) Airborne bathymetric laser scanning is the same, more or less, with the difference that a green laser is applied and the laser beam is facing forward and backwards. These differences enable the laser beam to penetrate water. Figure 1: TAG Pipeline System The TAG Pipeline System is used for supplying domestic customers in Austria as well as for the transit of natural gas to Italy. Via the SOL Pipeline System (Süd - Ost - Leitung) of Gas Connect Austria GmbH, which diverges at Weitendorf from the TAG Pipeline System, transit to Slove- nia is also possible. 1.2 PIPELINE MONITORING SERVICES 2017 TAG performed pipeline monitoring services in 2017, the bathymetric survey of 23 river crossings was part of it. Prior to those services a pilot project on 60 km was performed in 2016, the goal was to tailor the services to the needs of TAG. The applied technologies were airborne route videos, airborne laser scanning, photogrammetry (orthofotos, vectorisation) and airborne bathymetric laser scanning. Deliverables of those services were airborne videos of the route (HD/IR), 3D classified pointcloud, DSM, DTM, ortho- fotos, vectorisation (incl. polygons), raw data of the flights incl. aerotriangulation, flight strips, tiles, etc. and a report. The results of the airborne bathymetric laser scanning were finally integrated into 3D pointcloud derived from the airborne laser scanning. Figure 2: RIEGL, Scanner VQ-820-G Limiting factors for the water penetration are the flow speed of the water and the water turbidity. The less the flow speed and the clearer the water, the better and deeper the measurement. Haven’t seen your company in here? There is space for advertising! Contact us: firstname.lastname@example.org
20 PIPELINE TECHNOLOGY JOURNAL RESEARCH / DEVELOPMENT / TECHNOLOGY All on the market available sensors provide a parameter about their water penetration capability, that parameter is the Secchi depth. The Secchi depth is determined with a Secchi disk, which is a black and white, 20 cm diameter disk used for measuring the turbidity of water. The disk is lowered into the water until it just disappears from sight. The depth at which the disk disappears is called the Secchi depth. An assessment of the secci depth of rivers / waters to be crossed prior to a survey campaign is possible. 2.2 TAG – SETUP 2017 For the bathymetric survey of the 23 river crossings of TAG we selected a RIEGL VQ-820-G sensor with a Secchi depth of 1 and a given accuracy and precision of 25 mm under laboratory conditions. The sensor was mounted on a Cessna 182T, and it was operated on 400 m flight altitude above ground level. 3. CHALLENGE & IDEA is the required longer time for mobilization, survey, transfer to the next site, demobilization and processing. Longer weather dependency is another disadvantage furthermore limitations by vegetation for good sights during the survey need to be overcome. Finally only profile lines at selected locations are delivered, instead of an array of survey points for the riverbed. 3.3 HISTORY & PROJECT IDEA We received a sample data set of Riegl`s latest airborne bathymetric laser scanner in the beginning of 2016, and we were heavily impressed of that data set. Riegl is one of the world leading producers of laser scanners. 3.1 SPECIFICS OF RIVER CROSSINGS Pipeline river crossings are difficult, expensive and time consuming during design, construction and operation/ maintenance. River crossings are permanently threatened by flooding and washout. They need a special survey, a special design, special protection measures and finally they need to be monitored throughout the whole lifecycle. 3.2 CLASSIC SURVEY OPTIONS Bathymetry is the underwater equivalent to topography. The classic survey options for the bathymetry of pipeline river crossings are either by walk through or from a vessel. Walk through as long as river depth and flow speed allows to pass the river and from a vessel after walk through is not possible anymore. Walk through means to survey either by classical terrestrial survey or GPS. From the boat means to survey either by classical terrestrial survey or GPS from the boat, or survey by echo sounding or radar. Echo sounding or radar is usu- ally combined with GPS, these technologies can be applied for big water depths as well, which is their real strength. The main challenge of the classic survey approach is the related logistics. River crossing are usually spread out along the route, which is often a few hundred kilometers, and to perform this approach surveyors need to mobilize on site with all required survey equipment, including vessel if required. After the finalization of a crossing the survey team needs to transfer to the next crossing. Benefit of a classic survey approach is, surveyors are on site and see more location specific details. Disadvantage Figure 3: Test airborne bathymetric laser scanning Saalach, orthofoto and profile through the classified 3D pointcloud To be sure on the quality and the real capabilities of such a sensor we decided to perform a test including a compar- ison with a classic terrestrial survey. The test was per- formed on the river Saalach at the stretch of the Austri- an-German border. After the successful test and based on the experiences gathered from the test, we developed the idea of an alter- native solution for the survey of pipeline river crossings. We contacted TAG and presented the results, finally we were able to convince TAG to apply the technology for the bathymetric survey of the TAG river crossings. 4. SCOPE & RESULT The specified scope was to survey 23 selected river cross- ings along 380 km route with airborne bathymetric laser scanning. We applied the setup as described above, see chapter 2.2 TAG – Setup 2017. Two flights were required, one flight per day. The specified crossings were covered in both directions and we ended up with a point density of 14 pts/m². We captured 21 crossings and only for 2 crossings we got no results, due to water turbidity. The river width varied from 3 m to 191 m, and the captured water depth was up to 1.5 m. The processing of the captured data required 15 days, as processing is more extensive than regular processing of airborne laser scanning, due to the large amount of signal noise on the one hand and on the other hand due to some special processing steps.
RESEARCH / DEVELOPMENT / TECHNOLOGY PIPELINE TECHNOLOGY JOURNAL 21 5. RIVER CROSSING MUR This sample provides an overview about the results. The selected crossing of the river Mur is located westward of Weitendorf in Styria, the route splits up and TAG I cross- es the Mur southeast of TAG II and TAG Loop II. The river width is about 54 m and the water depth at the crossings is about 1.2 m. See the right image of figure 5, there is the biggest differ- ence to classic survey visualized, the result of airborne bathymetric laser scanning is an array of survey points for the riverbed. Figure 6 provides a profile of the Mur crossing of the TAG Loop II, it is composed of the points from the 3D point- cloud providing the vegetation in a corridor ± 2 m along the route, generated terrain from the classified ground points and the top of pipe received from intelligent pigging. Due to the array of survey points for the riverbed such profiles can be taken at any location on demand. Therewith it is easily possible to check the situation up- and down- stream of the crossing. Figure 4: Classified 3D pointcloud with integrated river section, 300 m 6. CONCLUSION The result is a classified 3D pointcloud including the water- body, which is the basis for a digital surface model (DSM) and a digital terrain model (DTM). It was agreed with TAG to integrate the crossing section into the data that were captured with the regular airborne laser scanning for the entire route. The intention was to have one dataset with a combined result from both technologies along the entire route. AIRBORNE BATHYMETRIC LA- 6.1 SER SCANNING VS. CLASSIC SURVEY The recommended surrounding conditions for both ap- proaches are the same, both should be applied during low water and not during the vegetation phase. Figure 5: Left: River crossing Mur, orthofoto and route Right: River crossing TAG II and TAG Loop II, 3D pointcloud waterbody switched off, intensity colored
22 PIPELINE TECHNOLOGY JOURNAL RESEARCH / DEVELOPMENT / TECHNOLOGY Figure 6: Mur crossing TAG Loop II, profile line & profiles with & without waterbody The results of both approaches are very different in their nature. Airborne bathymetric laser scanning provide an array of survey points and an orthofoto, as usually a digital airborne camera is used parallel to the airborne bathymet- ric laser scanner. The deliverables are the classified 3D pointcloud, DSM / DTM and orthofotos covering the speci- fied area. From those deliverables profiles can be extracted at any required location. Floodplains can be included and can be covered easily from the air. The result of classic survey are measured points along specified profile lines only, those are used to generate the profiles, beside a multibeam echosounder would be used. Floodplains can be included, but require additional terrestrial survey which is laborious. DTM can be generated by interpo- lation, using all collected survey points, but available survey points will be way less as from a laser scanning approach. In case of several river crossings along a route, the re- quired time for the flights is way less than the required time for performing classical survey, after the flights there is no more dependency on climatic conditions or water level, as the following processing works are performed in the office. Required time for TAG was 17 working days, 2 days for the flights and 15 days for the processing. Esti- mated amount of time for a classic survey is 25-28 days at least. This is an optimistic estimation valid for following assumptions, 1 survey team, 1 day per crossing including transfer, 2-5 days in-house processing and stable climatic conditions during the survey campaign. In our case the cost per crossing is about 25% less, than a classic approach. This conclusion is justified as followed, 23 crossings and 2 missed ones (which would have to be complemented).The cost per crossing of TAG were 2.000 €, Fugro Germany provided us with a general cost esti- mation for a classic survey of 3.000 € per crossing with a range of ±20% depending on the specific site conditions. As the cost is not linear increasing per crossing for air- borne bathymetric laser scanning, the cost decreases the more river crossings and the longer the stretch. 6.2 SCOPE OF APPLICATION The conclusion is that airborne bathymetric laser scanning is a good choice for river and water crossings with a water depth up to 1.5 m. Furthermore shoreline survey at landfalls of pipelines can be addressed with the technology as well. Depending on the expected positive development of the airborne bathymetric laser scanners the possible water depth will increase in the future. Actually it is the “bridge technology” between topographic survey and echo sounding from the boat and closes the gap between. For the crossings of lakes, big rivers or the sea additional echo sounding will be required. 6.3 BINED SURVEY APPROACH RECOMMENDATION - COM- Logistics for the flights is much easier, than for a classic survey. The aircraft is mounted with the sensors, transferred to the project area and the survey flight is performed. For a classic survey a survey team including all required survey equipment and vessel needs to be mobilized to the sites and good access to the location of the crossing assumed. Based on the on the experience of this project we rec- ommend a combined and stepwise survey approach of airborne bathymetric laser scanning and additional echo sounding or terrestrial survey on demand. A survey campaign should be started with airborne bathymetric laser scanning, followed with the check of
RESEARCH / DEVELOPMENT / TECHNOLOGY PIPELINE TECHNOLOGY JOURNAL 23 the results, this verifies which river crossings need to be complemented by classic survey and followed with the respective mobilization. Authors Rupert Kellerbauer Airborne bathymetric laser scanning shall always include airborne imagery (orthofotos) as this provides the required information of the situation at the site during the survey. gispc - geographic information system & processing consulting The type of crossing and potential limitations (water turbid- ity, flow speed) shall be taken into account right from the beginning to choose the right approach. Potential aircrafts for airborne bathymetric laser scanning are plane, helicopter and UAV (= unmanned aerial vehicle, drone). Depending on the scope of work and the surrounding condi- tions the right approach and carrier needs to be chosen. CEO email@example.com COMPLEMENTARY SERVICES FOR YOUR CORPORATE-COMMUNICATION Pipeline Technology Journal Offers multiple advertising opportunities to increase your company‘s visibility e-Journal Technical Articles e-Newsletter Latest News Website Information Hub IN OUR MEDIA KIT FOR 2020 YOU FIND ALL DETAILS ABOUT OFFERS, PRICES, TOPICS AND DATES www.pipeline-journal.net/advertise
Current View of Design and Evaluation of Sulfur Pipelines Dr. Kai Bauerbach, Dr. Paschalis Grammenoudis > MMEC Mannesmann GmbH Abstract The global production of natural gas is increasing continuously leading to development of gas fields with challeng- ing contents such as sour gas containing highly toxic hydrogen sulfide. In a process called “gas sweetening” the hydrogen sulfide is removed, yielding liquid elemental sulfur. This substance is not just a by- product of the natural gas production. A multitude of industries rely on elemental sulfur as a raw-material to be used in various chemical processes and products. Transporting liquid sulfur away from the gas extraction site raises the necessity for an infrastructure capable of dealing with the unique properties of this substance at elevated temperatures. Liquid sulfur can only be pumped in a limited temperature interval. Lower temperatures lead to solidification, higher temperatures will cause the sulfur’s viscosity to increase rapidly. Additionally, sulfur’s volume increases significantly during phase transition from solid to liquid. A pipeline system transporting liquid sulfur that must satisfy a characteristic set of demands. Hydraulic design ensures the proper operation parameters to meet the capacity requirements of the pipeline system. Thermal design’s core task is to ensure that the system can not only maintain the operation temperature and prevent heat loss but also provide additional input of thermal energy whenever needed. To manage the thermal stresses arising in pipe- lines operating at elevated temperatures appropriate mechanical design needs to be conducted. In a re-melt scenario the solid sulfur inside the pipeline needs to be liquefied. This poses additional requirements. Each of these demands and tasks such a pipeline system needs to satisfy (including boundary conditions dictated by the extraction plant) must be met with a specific and customized technological answer. Here, the authors provide a comprehensive overview of the challenges and selected technological approaches in the design and assessment of a liquid sulfur pipeline system.
RESEARCH / DEVELOPMENT / TECHNOLOGY PIPELINE TECHNOLOGY JOURNAL 25 1 INTRODUCTION 2 PROPERTIES OF LIQUID SULFUR For more than four decades world’s demand for natural gas has been growing . There is no current indication that this trend is going to change. This has led to the develop- ment of gas fields with increasing challenging contents such as high amounts of hydrogen sulfide (H2S, rotten egg gas). Natural gas extracted from gas fields developed in re- cent years contains up to 30 % of this this toxic component (see Table 1). An Amine treatment process (Claus process) more commonly known as gas sweetening the hydrogen sulfide is separated from the natural gas. As Hydrogen sulfide is highly toxic the extraction site is considered haz- ardous area and personnel working in this area is required to carry protective equipment and observe special HSE procedures. The gas sweetening process yields liquid elemental sulfur. For the transportation with freight trains or ships the sulfur is usually granulated or poured into blocks at a dedicated facility. Since the extraction site is considered a hazardous zone it is advisable to not have the solidification facilities at the extraction site if possible to minimize the number of persons exposed to the hazardous working environment. Transporting the liquid sulfur away from the gas extraction site raises the necessity for an infrastructure capable of dealing with the unique properties of this substance at elevated temperatures. Transporting liquid sulfur through a pipeline bears several difficulties. The characteristic properties of sulfur only al- low safe operation of such a pipeline within a defined tem- perature interval. Temperatures below this interval lead to solidification, at higher temperatures the sulfur’s viscosity increases rapidly. The lower bound of this interval is given by the solidification temperature at ca. 119 °C. As liquid sul- fur reaches temperatures above 155 °C it turns from bright yellow to orange, its viscosity increases rapidly reaching values that prohibit pumping and safe operation . Keeping the liquid sulfur at an operating temperature of 125 °C–145 °C ensures that the liquid sulfur will reach the destination site in a condition allowing for further process- ing (e.g. granulation). A thermal margin above the freezing temperature must be ensured during transport. Facilities following the pipeline (such as a granulation unit) will require the liquid sulfur’s temperature to be within defined limits leading to the operating temperature needing to consider possible thermal requirements of the receiving facilities. Additionally, sulfur’s volume increases significantly during the phase transition from solid to liquid which bears signif- icance in the (rare) cases of a re-melt operation. During solidification (freezing) sulfur shrinks by approxi- mately 10 %. The reverse phase transition of solid to liquid sulfur (melting) can lead to potentially difficult and dan- gerous scenarios. While melting, solid sulfur increases its volume by ca. 10 %. If this expansion happens in a con- fined space the potential structural implications could be devastating. Additional precautions and care is necessary when dealing with liquid elemental sulfur since it can yield a variety of toxic or dangerous compounds. Especially the presence of water and oxygen will lead to sour environ- ment that could potentially harm any equipment. Figure 1: Typical composition of natural gas, emphasis on possible content of hydrogen sulfide of sour gas 3 UID SULFUR PIPELINE TECHNOLOGY DIFFERENT APPROACHES IN LIQ- Due to the extraction of sulfur from hydrocarbons (ma- jorly natural gas) the mining of elemental sulfur has been in constant decline for many years . Other albeit rarer sources of elemental sulfur include desulfurization of crude petroleum or coke. The majority of the world’s elemental sulfur is used to produce sulfuric acid, a key component in the production of pharmaceuticals, dyes, fertilizer and numerous other industries. Globally, the con- sumption of sulfuric acid is widely regarded as an indicator of a nation’s industrial activity. While the world’s leading sulfur producing countries (2016) are the USA, China and Russia the top exporting countries include the UAE and Qatar due to their production exceeding the countries own usage . While transporting liquid sulfur in a pipeline it is impera- tive to maintain the operating temperature within a closely defined interval (see above). This includes to compensate for potential heat loss that could result in product solidifi- cation. A trace heating together with monitoring provides means to maintain thermal conditions state and ensure safe operation. While the station piping for liquid sulfur transportation is commonly steam traced this technology is not advisable for long range or cross-country transporta- tion. Liquid sulfur pipelines around the world rely on one of two technological approaches. The technological solution for trace heating employs either a water heat tracing or an electrical heating system (skin-effect heating).
26 PIPELINE TECHNOLOGY JOURNAL RESEARCH / DEVELOPMENT / TECHNOLOGY 3.1 TRICAL HEATING SYSTEM PROPERTIES OF AN ELEC- Electrical heat tracing is commonly accepted as a heating technology in a wide range of industrial applications such foundation heating, de-icing or heating of high-viscosity hydrocarbons. These pipelines are commonly constructed from pre-insulated pipeline spools. The product pipe and the carrier pipes are encased by insulation layers (see Figure 2). These spools are field welded at the construc- tion site. Any joints, bends or interface locations requiring on-site access to the product pipe are field insulated using mineral wool. An electrical trace heating (Skin Effect) sys- tem for liquid sulfur pipelines relies on self-limiting electri- cal heating cables in dedicated carrier pipes. These pipes are welded to the product pipe containing the liquid sulfur. Upon powering the electric heating cables, the carrier pipes are heated, converting electrical energy directly to thermal energy. Due to the thermal conductivity of the carrier and product pipes the induced heat is quickly available over the whole cross-section. In recent years, several sulfur pipe- lines at gas extraction sites in the middle east have been built utilizing electrical heating systems. The driving force of transferring heat to the product in case of an electrical heating system is the direct transfer of en- ergy. This transfer mechanism is essentially independent of the product’s temperature. The possible range of an electrical heating circuit is limited due to the type of available heating cables and their spe- cific classifications, conductivity, electrical resistance and design temperature. This requires the pipeline to be split into segments with dedicated individual heating circuit for each segment. Each of these segments requires facilities with power transformers as well as control units to operate. The heating circuits are installed using pull boxes along the pipeline. Postwelding the heating cables as well as temperature sensing cables are pulled through the carrier pipes. Accessibility for maintenance and repair requires such a system to be installed above ground. As this approach represents an unrestrained pipeline expansion loops are required to accommodate the thermal expansion. Proper guidance of the axial thermal expansions is provided by a fixation/restraining concept. Thermal deformations must not be restricted excessively to prevent thermal stress con- centration points. While management of thermal stresses is a key focus of mechanical design, interference with the insulation concept should be avoided as much as possible. As a support concept, above ground insulated pipelines commonly utilize a pattern of alternating expansion/ contraction loops and anchor blocks. The thermal expan- sion/contraction loops partially absorb the deformation, the resulting forces are transferred to the anchor blocks. Intermediate supports provide axial or lateral “guiding” rather than load bearing functionality (see Figure 3). The base construction for all supports and anchor blocks is commonly given by sleepers, concrete blocks the pipeline supports are resting on. Special attention is required for the design and construction of the anchors as these loca- tions need to meet the compromise between structural and thermal requirements in a most unique manner. Thermal design requires a uniform profile in heat loss behavior. The concept of a discrete single-point fixation, however, employs materials that can withstand the resulting forces. Commonly, high strength materials also are of high density and thus not well suited for thermal insulation. These par- tially conflicting demands of structural fixation and thermal insulation can lead to an inevitably increased heat loss at Figure 2: Cross section of an insulated, electrically heated pipeline; smaller tube at 12 o’clock position is used for temperature sensing the other two tubes contain heating cables
RESEARCH / DEVELOPMENT / TECHNOLOGY PIPELINE TECHNOLOGY JOURNAL 27 Figure 3: Aerial schematic of a pipeline support concept, alternating pattern of anchors and expansion/contraction loops with regular and guided supports the anchors. A similar, yet not as severe, situation arises at all other support locations where the compressive strength of the thermal insulation will be challenged to withstand the loads resulting from this fixation concept. that a higher amount of thermal energy carried by the wa- ter stream is absorbed by colder product and thus resem- bles a demand-oriented heating, delivering thermal energy at the locations where it is needed. 3.2 PROPERTIES OF A WATER HEATING SYSTEM A hot-water heating system is built as a pipe-in-pipe solu- tion with the innermost pipe as the product pipe while the water runs in the outer annular shaped cross section. Both pipes are additionally encased in an insulation layer (com- monly high-density polyurethane). As with a steam jacket system this solution results in additional thermal and me- chanical requirements for both pipes and welded spacers (see Figure 4) to ensure the concentricity of the two pipes. Proper delivery of thermal energy to the product can only be ensured if the pressure and temperature conditions of the water stream are also monitored and controlled. The mechanism of heat transfer in a water tracing solution will rely on convective heat transfer from the hot water through the product pipe wall to the sulfur. As the sulfur temperatures rises, this heat flow decreases. This ensures A water heat tracing solution will require almost no addi- tional infrastructure along the pipeline corridor. Instead, all necessary facilities (boilers, pumps) can be installed and operated at either (or both) end of the pipeline. A strict separation of water and sulfur is to be maintained to avoid possible formation of a corrosive environment. This solution is especially advisable for underground solutions. Still, for a buried hot- water heated liquid sulfur pipeline the thermal expansions and resulting forces must be accommodated. While underground expansion loops or an additional pipe serving as an underground conduit are possible there is also a well-documented example for a pre-stresses solution with long-radius bends, fully restraining the pipeline . In contrast to an above ground approach a buried pipeline system causes less interference with nearby infrastructure and can be considered protected against external impact and influences. Figure 4: Cross section of a water heat traced sulfur pipeline with product pipe, annular shaped water section and spacers
28 PIPELINE TECHNOLOGY JOURNAL RESEARCH / DEVELOPMENT / TECHNOLOGY A buried (restrained) pipeline operating at high tempera- tures is prone to stability failure . As the temperature difference between installation and operation tempera- ture exceeds 100 K, upheaval or lateral buckling of these pipelines could occur. If the lateral (or upward) displace- ment of the pipe exceeds the soil’s limit displacement as described in . The restraining forces exerted by the backfill need to be considered for the pipeline bends, observing limit values for stresses and displacement limit values in upheaval/lateral buckling calculations. Transferring the restraining forces of the padding and backfill to the casing and product pipe requires the insu- lation layer to withstand the resulting pressure and shear forces. These requirements on the structural strength of the insulation are comparable to the requirements arising for the supports in an unrestrained pipeline. 4 STAGES OF DESIGN One of the early steps in in the planning stage of each pipeline system is the route selection. While parts of this process could be considered basically independent of the selected technological approach some interactions might be necessary to consider. Route selection incorporates the conditions of terrain, soil elevation as well as nearby infrastructure but also non-technical interactions such as land ownership. Depending on the technology selected for a specific project, these criteria will be weighted differently. This process is not independent of the selected technolog- ical approach as the questions of heating technology and above/below ground are closely interwoven. For the engi- neering steps to follow, the resulting elevation profile is the most crucial input information for the hydraulic design. In addition to the elevation profile hydraulic calculations incorporate operating scenarios (e.g. shutting valves, pump trip) to conduct flow assurance calculations. The investiga- tions include information on the inlet side of the pipeline (pumps) and the pressure requirements on the outlet. Iden- tification of optimal operating conditions and flow assur- ance in transient operating scenarios. These scenarios are defined based on process considerations and include infor- mation defined in the facilities’ operating philosophies. As the hydraulic analyses assume that the product remains in a liquid state these calculations are conducted within the specified temperature interval but account for the change of the product’s properties in case of heat loss along the pipeline. Hydraulic design ensures the proper operation parameters such as flow velocity and pressure to meet the capacity requirements of the pipeline system. Thermal design’s core task is to ensure that the system can not only maintain the operation temperature and prevent heat loss but also provide additional input of thermal energy whenever needed. To manage the thermal stresses arising in pipelines operating at elevated temperatures appropriate mechanical design needs to be conducted. In a re-melt scenario the pipeline is filled with solid sulfur that needs to be liquefied. This poses an additional set of re- quirements. Each of the demands and tasks such a pipeline system needs to satisfy (including the boundary conditions Figure 5: Schematic of the interdependence and principal tasks of different design stages of a pipeline system
RESEARCH / DEVELOPMENT / TECHNOLOGY PIPELINE TECHNOLOGY JOURNAL 29 dictated by the extraction plant and surrounding location) has to be met with a specific and customized technological answer with regard to insulation/heating, monitoring of operation parameters or above/underground solutions. In general, materials will experience expansion and contrac- tion when heated or cooled. A material’s thermal expansion coefficient relates the temperature difference to the thermal strain. Any restriction of thermal strains will result in ther- mal stresses. The solution to not have these stresses or de- formations exceed the mechanical strength of the pipeline system is to either restrict or to allow for thermal expansion. In underground (restrained) pipelines the compacted pad- ding and backfill provides the necessary restriction while in aboveground (unrestrained) pipelines utilizes a combina- tion of guided supports and expansion loops to accommo- date the thermal expansion with only minimal restriction. Mechanical design employs analytical approaches - as well as state of the art numerical simulations to determine the stiffness (loop), forces (anchor), and stresses (pipeline). These approaches model the pipeline as beam sections and calculate the resulting stresses from axial forces and bending moments in each section. Anchors and supports of an above ground pipelines are a prime example of a specific interface location, where the scope of work for different engineering disciplines will overlap. At the anchors, the interface challenges of pipeline and civil engineering must be met to obtain a consistent engineering solution. Furthermore, at these locations the mechanical strength of insulation materials or the insula- tion capability of a structural fixation will be challenged. Answering these questions requires custom fit solutions to individual problems to be solved by engineering specialists. Proper design and solid engineering without neglecting cost-efficiency are necessary prerequisites for safe opera- tion. As Liquid sulfur pipelines are designed for long con- tinuous operation without downtime periods the scenario of regular operation does not include extended no-flow periods. Monitoring of key operating conditions (tempera- ture, flow rate, pressure) is essential to maintain operability and to recognize and avoid undesired scenarios. 4.1 SPECIAL SCENARIOS pipe. The flowing product provides a constant stream of thermal energy (or the lack thereof), providing a constant flux of thermal energy to/from the thermal weak spots. A possible power outage or malfunction in the heating system in conjunction with a no-flow situation may result in partial or complete solidification of the sulfur inside the pipeline. To re-establish the conditions for regular oper- ation, the heating system has to be used to re-melt the sulfur inside the pipeline . The implications of insulation weak spots at low or saddle points might be exacerbated in such a scenario. In de- manding elevation profiles with intermediate saddle points or local sags, colder product will accumulate at these locations. At these locations freezing starts and melting will take the most energy input. Additionally, any shrink- age of the product upon freezing will be counteracted by gravitational flow filling the cross section completely at low points, additionally impeding re-melt operations. This re-melt process is to be undertaken with great care as it is a crucial process that can potentially damage the pipeline beyond repair. Melting sulfur between frozen sulfur plugs without room for expansion will quickly lead to stress states exceeding carbon steel’s ultimate strength. In a perfectly horizontal elevation profile the sulfur would provide a continuous air pocket of 10 % vapor space. A draining system is a possible technology to avoid forma- tion of a frozen pipeline. Such a system uses valves at the pipeline’s low points to empty the content into designated draining pits. During a blackout scenario the draining pro- cedure will be initiated to avoid formation of frozen sulfur plugs. For obvious reasons a draining system is exclusive to an above ground pipeline system. The draining system also requires vents to be installed at the pipeline’s high points to enable a complete and successful draining of the pipeline’s content. Such a system provides an additional redundancy. In case of a looming prolonged shutdown (planned or emergency) the pipeline can be emptied to avoid a re-melting operation. Failure to drain as well as an incomplete draining of the pipeline results in a partially frozen pipeline and bears the same risks and difficulties as a completely frozen system. For regular operation the aggregate state of the sulfur will not be significantly impacted by any thermal weak spots. This might lead to the misconception that several of these locations might be considered negligible for the thermal behavior of the pipeline if these weak spots do not con- siderably lower the average insulation efficiency. However, the impact of a local thermal weak spot might be negligible for the scenario of regular operation and yet still heavily impact other operation scenarios. Local heat sinks are of minor importance while liquid is flowing in the product The redundancy provided by a draining system is howev- er to be seen in contrast to the introduction of additional potential thermal weak spots. The drain and vent locations represent interface locations. The re-melt process itself differs considerably between the different heating technologies. A hot-water system will start the re-melt process from the end where the hot water is injected. Thermal energy will be primarily absorbed by the sulfur at the end and the liquified section will extend
30 PIPELINE TECHNOLOGY JOURNAL RESEARCH / DEVELOPMENT / TECHNOLOGY from there. Since the thermal profile is expected to be mostly uniform without discrete interface locations a con- tinuous re- melt is to be expected. With electrical heat tracing, it can be difficult to obtain a uniform re-melt particularly near potential thermal weak spots. Depending on the elevation completely frozen and vapor spaces may exist along a single heating circuit. As the circuit can only be switched on or off along the whole running length this leads to a situation with uniform heat input for sections with differing demands. While a re-melt is still claimed to be possible, the procedure can be pro- tracted and needs very close monitoring of heat absorption and aggregate state. 5 ASSESSMENT AND CONCLUSIONS Depending on a wide range of specific boundary conditions such as, elevation profile, on-site process plants and spatial constraints either technological solution can be considered viable for a liquid sulfur pipeline. Installation and operat- ing cost will doubtless be considered when comparing the technological approaches for a specific project. While an above ground solution combines the advantages of easy accessibility, possible redundant heating circuits and constructability from pre-insulated spools to achieve an easier constructability it requires additional facilities for the power transformers and is more prone to external interference to its exposed location above ground. This exposed position, however, allows installation of technolo- gies preventing sulfur freezing (drain systems). A hot-water heated system – especially with a pre-stressed pipe-in-pipe underground system – requires a considerably increased engineering and installation effort. Beyond the increased complexity of the engineering an underground hot-water heated system provides a uniform thermal behavior with lower effort in maintaining a temperature profile due to the absence of discrete interface locations. The protection from external influence is accompanied by increased difficulties of access for repair and maintenance. Both heating technologies have been successfully installed and are operating at numerous locations all around the world. Design and construction of future systems can rely on the experiences gathered from these existing facilities. This allows to individually identify the best suited technol- ogy and economical solution for new liquid sulfur pipeline projects. Currently, MMEC Mannesmann is conducting the EPC for an electrically heated, drainable pipeline solution in the UAE. Construction is expected to be completed in 2019. Authors Dr. Kai Bauerbach MMEC Mannesmann GmbH Senior Discipline Engineer kbauerbach@mmec- mannesmann.com Dr. Paschalis Grammenoudis MMEC Mannesmann GmbH Head of Consulting / Technical Calculations pgrammenoudis@mmec- mannesmann.com References 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. BP statistical review of world energy, June 2018, 67th edition United States Geological Survey: USGS Minerals Information: Sulfur; https://minerals.usgs. gov/minerals/pubs/commodity/sulfur/ Tuller, W.N. (ed.), The Sulfur Data Book, New York: McGrawHill, 1954 Oil & Gas Journal 01/20/1997 Graeme G. King World’s longest sulfur pipeline operating smoo- thly after 3 years American Society of Civil Engineers (ASCE): “Guidelines for the Design of Buried Steel Pipe”; American Lifeline Alliances; July 2001 American Society of Mechanical Engineers: ASME B31.4-2006, “Pipeline Transportation Sys- tems for Liquid Hydrocarbons and Other Liquids” American Society of Mechanical Engineers: ASME B31.8-2007, “Gas Transportation and Distribution Piping Systems Bauerbach, K., Grammenoudis P., Schmidt, T.: “Heat Loss and Phase Transition in an Above Ground Liquid Sulfur Pipeline”; CADFEM Simulation Conference, Koblenz, 2017 Peters, K.: “About Upheaval and Lateral Buckling of Embedded Pipelines”; 3R, 2006 VDI Heat Atlas (digital version), Second English Edition, Springer, 2010 Brand awareness? Become a part of the ptj - Company Directory
15TH PIPELINE TECHNOLOGY CONFERENCE 30 MARCH -02 APRIL 2020, BERLIN, GERMANY Europe’s Leading pipeline conference & exhibition 900+ DELEGATES 90+ EXHIBITORS 50+ DIFFERENT NATIONS DELEGATIONS FROM 80+ DIFFERENT PIPELINE OPERATORS 6 One-Day Pipeline Seminars • • • • • • Pipeline Defect Assessment Difficult to inspect Pipelines In-Line Inspection of Pipelines Pipeline Life-cycle Extension Strategies Illegal Tapping / Theft from Pipelines Risk Assessment and Management of Pipeline Projects subjected to Geohazards Diamond Sponsor Platinum Sponsor Golden Sponsors Silver Sponsors www.pipeline-conference.com
32 PIPELINE TECHNOLOGY JOURNAL CONFERENCES / SEMINARS / EXHIBITIONS 900+ PARTICIPANTS 90+ EXHIBITORS 50+ DIFFERENT NATIONS The pipeline world as guest in Berlin: Pipeline operators from all over the world take part in Europe’s leading industry event: the 15th Pipeline Technology Conference and Exhibition (ptc) in Berlin. The leading European event for the pipeline industry is now taking place for the 15th time, this time from 30 March to 2 April 2020 in Berlin’s Estrel Congress Center. The ptc provides the international pipeline industry with a plat- form to discuss technical challenges and solutions and to discuss the future of the entire industry. Europe’s most important pipeline event is growing from year to year: “For 2020, too, we as organisers expect growth of between 15 and 20% compared to the previous year,” says Dr. Klaus Ritter, President of the EITEP Institute. For them, there is a series of high-ranking plenary sessions and panel discussions, all of which deal with topics of in- terest to operators worldwide. This includes classic topics such as “Safety” as well as current challenges in the areas of “Qualification & Recruitment”, “Difficult to Inspect Pipe- lines”, “Illegal Tapping” and “Climate Adaption”. Important future topics such as hydrogen transport and Power-to-X are also included in the programme. Another unique selling point of the ptc is its internationali- ty: “About two thirds of the participants come from abroad. Last year, we saw the greatest growth from Latin Ameri- ca and Eastern Europe, a large proportion of which were
CONFERENCES / SEMINARS / EXHIBITIONS PIPELINE TECHNOLOGY JOURNAL 33 pipeline operators,” says Dennis Fandrich, Chairman of the Pipeline Technology Conference. This makes ptc the most international event of its kind in the world. The conference will be accompanied by a trade exhibition at which leading technology and service providers and pipeline operators will be able to present their innovative pipe solutions. The suppliers will be present throughout the entire lifecycle of the pipeline. With more than 90 ex- hibitors, a new record is also expected in this area in 2020. The conference and the trade exhibition will be comple- mented by thematically oriented one-day seminars, work- shops and operator discussion rounds in which partici- pants will be able to delve deeper into various topics. As every year, the conference papers will be made avail- able to the specialist public via the freely accessible “Pipe- line Open Knowledge Base”: https://www.pipeline-conference.com/abstracts. 80+ Pipeline Operators
34 PIPELINE TECHNOLOGY JOURNAL COMPANY DIRECTORY . Association IAOT - International Association of Oil Transporters Czech Republic www.iaot.eu/ DVGW - German Technical and Scientific Association for Gas and Water Germany www.dvgw.de Automation Siemens Germany www.siemens.com Yokogawa Japan www.yokogawa.com Certification Bureau Veritas Germany www.bureauveritas.de DNV GL Norway www.dnvgl.com TÜV SÜD Indutrie Service Germany www.tuev-sued.de/is Cleaning Reinhart Hydrocleaning Switzerland www.rhc-sa.ch/rhc/ Coating 1/2 Denso Germany www.denso.de Kebulin-gesellschaft Kettler Germany www.kebu.de POLINOM Russia www.rikol.ru Coating 2/2 Polyguard Products United States www.polyguard.com Premier Coatings United Kingdom www.premiercoatings.com/ RPR Technologies Norway www.rprtech.com/ Shawcor United States www.shawcor.com Sulzer Mixpac Switzerland www.sulzer.com TDC International Switzerland www.tdc-int.com TIAL Russia www.tial.ru TIB Chemicals Germany www.tib-chemicals.com Construction 1/2 BIL - Federal German Construction Enquiry Portal Germany www.bil-leitungsauskunft.de Herrenknecht Germany www.herrenknecht.com IPLOCA - International Pipe Line & Offshore Contractors Association Switzerland www.iploca.com Liderroll Brasil www.liderroll.com.br LogIC France www.logic-sas.com
PIPELINE TECHNOLOGY JOURNAL 35 COMPANY DIRECTORY Construction 2/2 Inline Inspection 2/2 MAX STREICHER Germany www.streicher.de/en Petro IT Ireland www.petroit.com VACUWORX Netherlands www.vacuworx.com Vintri Technologies Canada www.vintritech.com Vlentec Netherlands www.vlentec.com Construction Machinery Maats Netherlands www.maats.com Worldwide Group Germany www.worldwidemachinery.com VIETZ Germany www.vietz.de Engineering ILF Consulting Engineers Germany www.ilf.com KÖTTER Consulting Engineers Germany www.koetter-consulting.com Inline Inspection 1/2 3P Services Germany www.3p-services.com A.Hak Industrial Services Netherlands www.a-hak-is.com Baker Hughes United States www.bakerhughes.com Intero Integrity Services Netherlands www.intero-integrity.com/ Kontrolltechnik Germany www.kontrolltechnik.com KTN AS Norway www.ktn.no LIN SCAN United Arab Emirates www.linscaninspection.com NDT Global Germany www.ndt-global.com Pipesurvey International Netherlands www.pipesurveyinternational.com PPSA - Pigging Products and Services Association United Kingdom www.ppsa-online.com Romstar Malaysia www.romstargroup.com Rosen Switzerland www.rosen-group.com Inspection 1/2 Ametek – Division Creaform Germany www.creaform3d.com Applus RTD Germany www.applusrtd.com
36 PIPELINE TECHNOLOGY JOURNAL COMPANY DIRECTORY Inspection 2/2 Leak Detection 2/2 EMPIT Germany www.empit.com Integrity Management Metegrity Canada www.metegrity.com Pipeline Innovations United Kingdom www.pipeline-innovations.com Leak Detection 1/2 Asel-Tech Brazil www.asel-tech.com Atmos International United Kingdom www.atmosi.com Direct-C Canada www.direct-c.ca Entegra United States www.entegrasolutions.com Fotech Solutions United Kingdom www.fotech.com GOTTSBERG Leak Detection Germany www.leak-detection.de Liwacom Germany www.liwacom.de MSA Germany www.MSAsafety.com/detection OptaSense United Kingdom www.optasense.com Pergam Suisse Switzerland www.pergam-suisse.ch PSI Software Germany www.psioilandgas.com sebaKMT Germany www.sebakmt.com SolAres (Solgeo / Aresys) Italy www.solaresweb.com VEGASE France www.vegase.fr Monitoring Airborne Technologies Austria www.airbornetechnologies.at Krohne Messtechnik Germany www.krohne.com PHOENIX CONTACT Germany www.phoenixcontact.de/prozess SolSpec United States www.solspec.solutions Operators 1/2 Transneft Russia www.en.transneft.ru/
PIPELINE TECHNOLOGY JOURNAL 37 COMPANY DIRECTORY Operators 2/2 TRAPIL France www.trapil.com/en/ Qualification & Recruitment YPPE - Young Pipeline Professionals Europe International Safety 2/2 HIMA Germany www.hima.de Signage Franken Plastik Germany www.frankenplastik.de/en Pump and Compressor Stations Surface Preparation TNO The Netherlands www.pulsim.tno.nl MONTI - Werkzeuge GmbH Germany www.monti.de Repair Trenchless Technologies CITADEL TECHNOLOGIES United States www.cittech.com Clock Spring NRI United States www.clockspring.com RAM-100 United States www.ram100intl.com T.D. Williamson United States www.tdwilliamson.com Research & Development Pipeline Transport Institute (PTI LLC) Russia www.en.niitn.transneft.ru Safety 1/2 DEHN & SÖHNE Germany www.dehn-international.com/en Bohrtec Germany www.bohrtec.com GSTT - German Society for Trenchless Technology Germany www.gstt.de Rädlinger Primus Line Germany www.primusline.com Valves & Fittings AUMA Germany www.auma.com Zwick Armaturen Germany www.zwick-armaturen.de Further boost your brand awareness and list your company within the ptj - Company Directory www.pipeline-journal.net/advertise
IF YOU ARE READING THIS WE NEED YOU Host a webinar / site visit Promote membership Provide support / mentoring Sponsor a YPPE event Don’t just be in the industry, be a part of it Find Us! Young Pipeline Professionals Europe yppeurope.org firstname.lastname@example.org In the next Edition of ptj: December 2019 Third Party Impact The next issue of Pipeline Technology Journal (ptj) will address Pipeline Third Party Impact This is a great opportunity for skilled authors to submit insightful papers and to contribute to the global pipeline industry’s constant professional exchange.
15TH PIPELINE TECHNOLOGY CONFERENCE Europe’s Leading Pipeline Conference and Exhibition 30 MARCH - 2 APRIL 2020, ESTREL CONVENTION CENTER, BERLIN, GERMANY www.pipeline-conference.com Next Issue: December 2019 Pipeline Technology Journal In the next Edition of ptj: Third Party Impact www.pipeline-journal.net Event Calendar ADIPEC 11 - 14 November 2019 Abu Dhabi, UAE 15th Pipeline Technology Conference 30 March - 2 April 2020 Berlin, Germany Global Petroleum Show 9 - 11 June 2020 Calgary, Canada UESI Pipelines 2020 Conference 9 - 12 August 2020 San Antonio, USA IPC - International Pipeline Conference 28 September - 2 October 2020 Calgary, Canada
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