9 1 0 2 / 4 e u s s I e Journal Pipeline Technology Journal PIPELINE PLANNING & CONSTRUCTION www.pipeline-journal.net ISSN 2196-4300

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: ptj@eitep.de 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

PIPELINE TECHNOLOGY JOURNAL 5 ptj Editorial Board CHAIRMAN Dr. Michael Beller, Director Global Market Strategy, Rosen Europe MEMBERS Max Wedekind, Managing Director, Asle Venas, Senior Principle Pipeline DENSO Specialist, DNV GL Steffen Paeper, Senior Offshore Commissioning Engineer, South Stream Mark Iden, Chief Executive Officer, SkyData Air & Space Belkacem Bechka, Freelance Pipeline Consultant Admir Celovic, Director Publications, EITEP Institute Andreas Antoniou, Senior Research Associate, National Technical University of Athens Tobias Walk, Managing Director, ILF Mahmoud Abdel Hakim, Pipeline Engineering Team Leader, ADNOC Offshore e Journal President: Dr. Klaus Ritter Register Court: Amtsgericht Hannover Company Registration Number: HRB 56648 Value Added Tax Identification Number: DE 182833034 Pipeline Technology Journal www.pipeline-journal.net ptj@eitep.de Publisher Euro Institute for Information and Technology Transfer GmbH Marie-Jahn-Straße 20 30177 Hannover, Germany Tel: Fax: URL: +49 (0)511 90992-10 +49 (0)511 90992-69 www.eitep.de Used Copyright Material: P. 4; 32; 33 ©Philip Wilson P. 10 ©Shutterstock.com/ Inked Pixels; katatonia82 P. 38 ©Shutterstock.com/ serato Editor in Chief Dr. Klaus Ritter E-Mail: Tel: ritter@eitep.de +49 (0)511 90992-10 Editorial Board ptj Editorial Board Editorial Management & Advertising Admir Celovic E-Mail: Tel: Design & Layout Constantin Schreiber: c.schreiber@eitep.de celovic@eitep.de +49 (0)511 90992-20 Editorial Staff Dennis Fandrich: fandrich@eitep.de Mark Iden: iden@eitep.de Terms of publication Six times a year

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

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.muscillo@logic-sas.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

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

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

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

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

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: celovic@eitep.de

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

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 rupert.kellerbauer@gmail.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

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 [1]. 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 [3]. 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 [2]. 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 [2]. 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).

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 [4]. 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

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 [5]-[7] 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 [8]. 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

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

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

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

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

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