The development of third world countries is surrounded by a thousand challenges, one of them is to increase and modernize the transport infrastructure to improve competitiveness in an increasingly interconnected world. Colombia in recent years has undertaken a titanic task of construction of highways to meet this purpose, have hired more than 8170 km of roads, however, this task generates a major challenge for the oil industry since the construction of these roads generates an unplanned interference with the hydrocarbon transport infrastructure that, if not handled correctly, can cause ruptures or damage in the pipelines and the consequent economic and environmental losses. In 2015 the design of the highway that interconnects the municipalities of Remedios and Caucasia in the department of Antioquia began. This project was called Autopistas del Nordeste. The road was designed to pass through the Pocune river valley, however, the environmental licensing of this type of project requires the revision of the interference with other networks. It was found that the new road crossed the Ocensa pipeline at 26 points. The geographical conditions require the use of this small corridor by many lines, 2 pipelines (Ocensa and ODC), a 500 KV power line and, of course, the current tertiary route and the projected highway that connects these municipalities. The challenge is huge, in this article the project is described, the negotiation stages that have been necessary to carry out with the way to make compatible the projects and the threats that have been overcome in the constructive stage.

Gross Disproportionation concept is used as indicator once risk reduction measures are required. This indicator shows that a measure must be implemented if its cost (i.e. Capital Expenditure), is not grossly disproportionate if compared to benefits — represented by casualties suppression — reached by the measure. Due to this, a risk reduction measure is reasonable feasible unless its cost is highly disproportionate in comparison to its benefits. In hydrocarbon transportation industry, benefits represent the avoided cost if threats take place; on the other hand, for risk mitigation cost estimation, the cost per casualty averted must be accounted. The latter, provides a global cost of the mitigation measure adopted in relation to the direct cost of construction, with the reduction of the level of risk (i.e. social risk) and with the expected design period for that measure. In this last concept, the higher the reduction in the level of risk or the longer the design period of the mitigation measure, the lower the cost per casualty averted, a fact that reflects an effective mitigation measure in terms of risk reduction and its durability. This document shows, from a case study, how the application of the concept of grow disproportionation allows to select the type of optimal intervention over Ocensa’s pipeline, with the most favorable relation between cost and benefit, and the effective risk reduction level.

Geohazards have the potential to adversely affect the operation or integrity of an existing pipeline, or the routing, design, and construction of a proposed pipeline. Identifying, characterizing, evaluating, and if necessary, mitigating and monitoring geologic hazards have become critical steps to successfully and safely building and operating pipelines in the Appalachian Basin region of the United States. The recent, rapid expansion of pipeline construction and operation in the region, along with natural geologic and geographic conditions which are conducive to landsliding and ground subsidence, have resulted in a recent increase in geohazard-related incidences both during and post-construction of pipelines. As such, there is an increasing need to recognize, understand, and closely manage geohazards in this region, prior to, during, and post-construction of pipelines. This paper will provide an overview of essential tools that have proven most useful in this region, to identify, characterize, and ultimately mitigate and monitor potential geohazards. This paper will also provide insight on how to evaluate specific project needs and best-fit approaches and solutions for the project at hand, to reduce the operator’s risk. A case study will be presented from the Appalachian Basin region, including how a phased approach was used to assess and manage geohazards. The phased approach includes (1) Phase I Assessments, which consist of a regional-scale desktop assessment to identify, initially characterize, and qualitatively classify (e.g., low, moderate, high hazards) geohazards; (2) Phase II Assessments, which consist of a non-intrusive ground reconnaissance completed at targeted sites; and (3) Phase III Assessments, which consist of subsurface investigations such as drilling, test pitting, or geophysical surveys to further characterize specific hazards. The information obtained from the phased approach can be used for the design of mitigation and/or monitoring, if deemed necessary. Overall approaches to selecting and utilizing best-fit mitigation and monitoring options, both during and post-construction, fit for the regional conditions and to the individual project, will also be discussed.

The design and construction planning of pipelines is a multidisciplinary effort that requires support and input from geotechnical, geomatics and pipeline construction specialists. The cooperation between those disciplines is more pronounced and required when the pipeline traverses rugged mountainous areas with challenging settings. This paper begins by considering the range of topographic, geological, construction and other route datasets and how they are generated. A presentation of an application that has been developed and utilizes progressively improving route datasets as projects advance to generate Right-of-Way (ROW) footprint and detailed construction quantities such as granular excavation volumes, supply and demand quantities and cross-section details is introduced. An overview of construction details including construction direction, seasonality, and ROW profile is then offered. In addition, several analytical methods are available for deployment, each being suited for various stages of a project’s development. These analytical methods include advanced workbooks and GIS Enabled Applications that leverages DTM information as well as commercially available packages. A discussion of these methods is presented together with suggested guidelines as to when to apply them in a proposed project’s phase. Finally, lessons learnt from the experiences gained in several major projects are summarized.

TGN operates a system of 9,000 kilometers, with a long stretch traveling next to the foothills. Although it is clear now that this path may not be the best choice, it was defined for access convenience parallel to a national highway back in 1960, when erosion was not an important issue. Whenever a pipeline crossing is located at a place where a river experiences a break in its slope, development of meanders poses a significant threat to its integrity. The interaction between a rigid structure and a changing environment sets the scenario of a problem that needs constant attention. Thus, meanders become the main cause that leads to the implementation of expensive remediation works. In the following paragraphs, a method of evaluating meanders is presented based on concepts of channel stability regarding river curvature, width, slope and flows. This is complemented with real cases in which theoretical aspects are matched with actual crossings, its construction characteristics and the evolution of meanders with time. Long term performance of typical solutions such as soil movement channeling, bank protections, jetties and pipeline lowering are compared. Finally the inverse problem is addressed in which guidelines for the design of a new crossing are listed.

Integrity Management on Cenit common Right-of-Way (ROW), contemplate a preventive vision respect the impact that new infrastructure projects can cause in hydrocarbon transportation systems directly and indirectly. By including the management of Climate and External Forces Threat from this preventive approach have been identified mitigation and/or maintenance actions of which must be considered in the arrangements of common right-of-way with external entities responsible for the planning, construction and operation of these projects. This document presents the management strategy that was built an implemented largely, and the exposed examples are intended to show the importance of incorporates these learned lessons in the management of geotechnical assurance of the ROW.

To control the threats from external forces, pipeline owners and operators require detailed information about their pipeline infrastructure and the environment surrounding that infrastructure. The contribution from geographic data is recognized as an increasingly important part of a complete integrity management program, particularly for the identification of geohazards. This is because geohazards are generally characterized by high spatial variability, are complex and difficult to quantify but may result in catastrophic failure of pipelines. In recent years we have seen widespread technological development surrounding the processes to capture information in order to deliver quantitative inputs for pipeline engineers, risk & geotechnical experts. International codes & best practices (e.g. AS 2885.1-2012) state that “Environmental impact assessment is not simply a vehicle to obtain regulatory approval, it is a critical element of the planning for design, construction and operation of the pipeline.” Furthermore, geohazards frequently develop during the service life of pipelines. Consequently, regulators recommend that assessments are conducted on an ongoing basis to identify all potential threats and implement mitigation measures. A process has been developed to create efficient and economical solutions for monitoring and assessing the significance of pipeline bending strain and whether actual movement has taken place. This process can make use of a variety of inputs including slope gradient, climate, groundwater conditions, slope instability, seismic intensity, and environmental impacts, and can provide important information in the determination of potential mitigations. This paper will review the benefits which can be gained from the implementation of integrated approaches to inform geohazard management.

The OCENSA pipeline crosses the Valley of the Magdalena river flood on its way to the Caribbean Sea, the area of the valley is commonly inundated during the rainy season on shallow waters that remain flooded swamps. These swamps soils are composed by extremely soft peat with thicknesses greater than 15 meters. In June 2016 started the construction of a highway with an embankment of 6 meters in height which was more than 30 meters away from the OCENSA 30” pipeline, Due to the high compressibility of peat, to construct the road the soil is subjected to a process of consolidation and the height of the embankment was corrected adding more material. In July 29 2016 occurs a failure by load capacity on the ground under the embankment and as a result of this fault a lateral displacement of the adjacent soil producing a horizontal displacement in the pipeline of more than 50 cm. This document shows results from the affectation to the pipe and the measures taken to correct the situation.

Oil pipelines and gas pipelines usually go through geotechnically unstable areas for different reasons. These can go from situations related to the engineering stage (trace), to environmental and social aspects during the construction process. Due to these aspects, the ducts go through geotechnically undesirable areas. Usually, the geotechnical instabilities, according to the kind of movement, are low speed (cm/year), medium (m/year) and very quick processes that generate movements of tens to hundreds of meters per day. Most of Mass Removal Phenomenon (MRF) are triggered by rain and/or earthquakes and are translated into land movements which at the same time involve, occasionally, important deformations in pipelines or its breaking, depending on the movement speed and the possibility of making works before the pipeline breaking. To get to know the pipeline tensional state from the beginning of the pipeline operation, in this unstable zones, is an essential task, which depends on the early identification of the said land movements and the possibility to do measurements on the pipelines using tools such as In-line inspection running (ILI) or the installation of strain gauges. This situation makes the task of monitoring in unstable zones a vital one. The current paper is based on a breaking pipeline case due to soil movement, “monitored by inclinometers”, with the purpose to show the importance of a geotechnical and mechanical instrumentation that offers useful results. The instrumentation allows to model the interaction soil-pipeline to accomplish relevant tasks, that avoid the pipeline breaking and at the same time allow to stablish deformation thresholds of soil or pipeline, which will become early warnings to avoid breakings. Furthermore, the soil and pipeline’s deformation thresholds are documented, based on a system transport by pipelines (STP) breaking cases, to stablish threat classifications to a specific pipeline. The called instrument reading in real time implies: detection, measurement and data broadcasting that allows the user to have daily records of the movements or required associated variables, with no need to depend on other communication systems that might be inexistent in some areas. This paper also shows the development and operation of a monitoring station that includes: inclinometers, piezometers, strain gauges and rain gauges, among others. These broadcast their data to a server that the user has access to, from any place with a Wi-Fi network, here the user will be able to display information from each one of the instruments, emphasizing the measured variables or magnitudes (displacement, water level, micro strain mm/day) into graphics. The station has a limitation over battery length of 6 months, when it’s problematic to install a recharge solar cell system.

An analysis was performed of the charts that are traditionally employed in the determination of the separation of geotechnical protective structures on rights-of-way, such as cut-offs and trench barriers. An analysis was performed for the specific study area, with information from the existing weather and rainfall stations, which made it possible to characterize more accurately the rainfall figure required for curve fitting. Furthermore, knowledge of the soils in the area made it possible to classify them in terms of erodability. This classification was used to establish curves that better reflect the actual conditions of the soils of the rights-of-way. A conceptual analysis was performed of the need for the implementation of these structures in order to control erosion along the rights-of-way. This analysis made it possible to propose changes in the materials specification, in order to optimize costs during construction. As a supplement to the study of the protective structures for the rights-of-way, the dimensions of the trench for the installation of the pipelines was analyzed. This analysis included a comparison of the actual construction dimensions of the trench against the dimensions recommended by international standards and the ones contained in the international literature. Certain Colombian projects that supplement the analysis are also cited. The foregoing findings were used in the preparation of certain recommendations regarding the reduction of the dimensions of the trench for certain specific technical, social, and environmental conditions. Last, based on the analyses that were performed, the study proposes certain changes in the operator’s current standards, primarily regarding items such as cut-offs, trench barriers, and the dimensions of the trench. These changes will lead to a reduction in the construction costs of the geotechnical protective structures for hydrocarbon-pipeline rights-of-way. These items are typical, because the pipelines in question are located predominantly on foothill plains.

Long range, distributed fiber optic sensing systems have been an available tool for more than a decade to monitor pipeline subsidence integrity challenges. Effective deployment scenarios are an important decision to be factored into the selection of this monitoring equipment and typologies relative to specific project needs. In an effort to analyze the effectiveness of various fiber optic deployment conditions, a controlled field experiment was conducted. Within this field experiment, a variety of distributed fiber optic sensors and point sensors were deployed in predefined positions. These positions relative to the pipeline were selected to support a range of deployment needs including new construction or retrofitting of existing pipelines. A 16-inch diameter by 60-meter long epoxy coated pipeline that was capable of being pressurized to mimic operating conditions was utilized. This test pipe was installed in a typical trench setting. Conventional point gauges were installed at key locations on the pipeline. Fiber optic sensor cables were installed at key locations providing 14 alternative scenarios in terms of sensitivity, accuracy, and cost. After construction of the test pipeline, real time continuous monitoring via the array of conventional and fiber optic sensors commenced. A deep trench was excavated adjacent and parallel to the central portion of the pipeline which began to induce subsidence in the test pipeline. Continued monitoring of the various sensors produced real time visualization of the evolving subsidence. A comparison of the reaction of the sensors is compiled to provide an intelligent selection criteria for integrity managers in terms of accuracy, deployment, and costs for pipeline subsidence monitoring projects. In addition, further analysis of this sensor data should provide more insight into pipeline/soil interaction models and behaviors.

Oil and gas pipelines that pass through mountainous terrain are subject to an increase in the number of sections affected by the bending deformation’s resulting from external forces, which, when coupled with the construction and operational processes of the systems, cause mechanical damage to the pipelines that has led to containment losses, resulting in operational cost overruns and harmful effects on the environment and on nearby communities, while leaving at high risk the integrity of the petroleum infrastructure. By using primary data obtained through so-called “smart” in-line inspections or intelligent line inspections (ILIs), the occurrence and magnitude of these deformations and displacements of the pipelines can be determined. With the aid of geotechnical analytical techniques, this information can facilitate the interpretation of the processes that induce these thrusts. The starting point is the existing knowledge of the characteristics of the installation of the pipelines and of the clearances permitted by the rules and/or reference standards of the industry. The next step consists of comparing that data against the XYZ Data inertial mapping data (obtained through rotations of the XGP geometric tool) in one or more ILI runs, as part of the mechanical analysis procedure. As a recommended practice, an algorithm is developed for handling the ILI data, showing in parallel the geotechnical zoning data, illustrating it with a study algorithm.

Throughout the operation of the Camisea Pipeline Transport System [“En el Sistema de Transporte por Ductos”] , sites have been identified that are sensitive to landslide phenomena that might jeopardize the integrity of the pipelines. In the rainforest section, during the rainy season (which runs from November to March), the Continuous Monitoring Groups [“Grupos de Vigilancia Continua”] (GVC) for the right-of-way (ROW) program was launched, whose mission is to identify, in the field, the geotechnical conditions for each point, and to define possible maintenance or remediation solutions. The year-to-year reports of the GVCs are used to perform an analysis of the geotechnical condition of each site, which analysis is rated according to the Geointegrity Matrix, so that in this way the Master Plan, which is the program of work activities for a given year, can be established. In October of 2012, several incidents of public disorder occurred in the rainforest section, which led to the departure of the maintenance staff and ultimately the suspension of all activities, including the construction of the remediation and maintenance structures. The activities of the GVCs for the 2012, 2013, and 2014 rainy seasons were also canceled. The situation precluded the acquisition of ROW evaluation information, which is the primary input for the preparation of the Master Plan for the Execution of the Work Activities for each year. In view of this situation, it was necessary to use alternative methods in place of the customary monitoring processes, through overflight surveillance programs, a review of the historical information, and a follow-up based on the existing information. This paper describes the rating methodology that was used to determine the susceptibility of the risk of failure. This methodology allowed us to prioritize the intervention operations at specific points along the ROW that were the subject of stabilization work done on a standby basis, work performed during previous seasons, and locations rated as “High” and “Very High” in the geointegrity matrix. The application of this methodology makes it possible to identify, with a high degree of accuracy, the conditions at a point that is susceptible to an incident, and to compare it for the purposes of prioritization in connection with an intervention operation or the monitoring activities. This methodology provides a rating of the situational status of the point within the Pipeline Transport System (STD), with the incorporation of both recent and historical data. The goal of the Failure Susceptibility Index [“Índice de Susceptibilidad de Falla”] (ISF) evaluation procedure is to determine, in accordance with a set of analytical criteria defined through the preparation of a conceptual model, the conditions of the status of the sites that are susceptible to landslide phenomena, and also to determine a rating that makes it possible, within a cloud of points with similar characteristics, to apply a consistent and reliable method for prioritizing intervention operations (either through structures or through monitoring), and the latent risk condition in relation to the potential risk of a future failure.

The Norandino pipeline, build between 1998 and 1999, begins at the town of Pichanal nearby Orán in Argentina where it is connected to Argentinean Gas Transport System, It runs towards west crossing the Yunga in Salta province, climbs the Sierras Subandinas and the Cordillera Oriental through highly erosive environment, descends to Humahuaca city in Jujuy Province, crosses the Altiplano plateau, and reaches Chile through Paso de Jama then climbs up to 4.980 mas, crosses the Atacama desert to finally arrives at Tocopilla, Mejillones and Coloso cities. With 1070 km long and 20″ diameter, it’s capable to carry 4,6 million cubic meters per day expandable up to 8. The most hazardous part of the alignment is the Sierras Subandinas area, due mainly to geology and heavy rains. The east slope of the Cordillera Oriental, where the risk arises from the intense geodynamic and strong erosions in river crossings and landslides because of heavy rains that reach 1.500mm in four month, from December to March. In Cuesta de Mal Paso site, in front of San Andrés village in Salta Province, the pipeline should be laid along the hillside on a slope formed by the anticline limb, whose exposure to heavy erosion of the San Andres river at the base of the slope, the bedding to the river and seismic conditions of the region, constitute a geological and geotechnical risk to the pipeline integrity. The evaluation of deformation measurements of the slope, measured along several years, provided the necessary arguments to undertake the construction of tunnel in rock of 750 meters long and 2.5 meters wide and high, allowing the pipeline to pass below the main slip surface and therefore protecting it from a possible slide of the superficial layers of the slope. This paper describes the geological conditions, the geostructural situation of Cuesta de Mal Paso, the deformation monitoring system, the evaluation of the auscultation measurements, the design of the tunnel, the meaningful geological and geotechnical aspects of the tunnel construction and, finally, criteria for definition the auscultation system to monitoring the behavior of the tunnel and the Cuesta de Mal Paso slope.

The experience gained during the operation and maintenance activities on the Camisea Pipeline Gas Transport System (SDT) owned by TGP in Peru — which goes from the Amazon rainforest in the region of Cusco to the Pacific coast near Lima, along 729 Km — has led to the evolution and the optimization of the design, construction and maintenance processes regarding works focused on the stabilization of the slopes along the right of way of the pipeline carrying natural gas and natural gas liquid. This section of the right of way is 95 km long and crosses tropical mountains in the Amazon rainforest, in a transitional area between the Manugaly valley and the basin top boundary. It was noticed since 2005 that the right of way had being affected by a land slide consisting of a horizontal crack in the ground, between both pipelines and along them. So, after number of in-site inspections, the team concluded that the area was being affected by a large ground removal event. As a consequence, traces of geotechnical instability were found on the right side of the right of way, consisting of stress cracks, transverse settlements and leaks. All of those were affecting the stability conditions of the ground. From the annual in-site follow-up, monitoring and geotechnical testing, the team established that this process affecting the right of way was caused by a large mass removal process directly related to the increase of the imbalance rate of an old colluvial deposit below the entire area, triggered by the heavy rainfall in the area — ca. 3 500 mm a year, mainly between October and April. It is to be mentioned that the axis of the NG and NGL pipelines is located on the top of this colluvial deposit, which is susceptible to landslides. This is noticeable because of cracks present in the place. Local geomorphology and heavy deforestation — caused by locals — triggers an increase of the rainfall water filtration rate into the ground, thus speeding up the slide processes. Piezometers installed in the area showed high levels of the local water table. Movement readings are: top length: 70 m; length: 250 m; width: 150 m. Criteria for the construction of landslide mitigation structures in the pipeline área are being established based on a permanent land survey monitoring system — including inclinometers, piezometers and strain-gages — as this is a large regional movement. This control action allowed the operation to continue free of damages to the pipelines and under controlled costs.

The bi-national pipeline Loma de la Lata (Argentina)-Talcahuano (Chile) belonging to Gas del Pacifico, crosses the Andes at Latitude 37.1° South (Buta Mallin pass), following the Lileo river valley. In the region, there are large ancient landslides within an area of about 50 km2, which have been attributed to Holocene glaciations and seismic activity. In the winter of 2005, when snow limited the access to the area, it was found a pressure loss, that later was attributed to a landslide in a sector of the south bank of the valley. The adiabatic expansion generated a considerable volume of frozen soil around the pipe. The following summer it was studied the characteristics of the sliding and analyzed different solutions of the affected section. The geotechnical study showed details of the slipped area and its relationships with ancient landslides. It was found by comparative analysis of aerial photographs that an old slide about 1 km 3 was not fully reactivated. The general morphology has remained unchanged at least in the last 50 years, when the oldest aerial photography was taken. As additional verification, it was found that a small set of cascading ponds located in the slipped mass, has remained stable at that time, bearing the influence of the great 1960 Mw = 9.6 Valdivia earthquake. It was identified tension cracks delimiting the slipped area that was a modest portion of the historical landslide. Geotechnical parameters were estimated by back analysis of the land involved and it could establish a model for sliding mass process. A general analysis of long-term stability took into account the influence of distant earthquakes such as the subduction zone, which has a recurrence of about 100 years and other local seismic sources. Prior to define the most appropriate solution, a 250 meters long trench was dug preventively releasing the pipeline from the terrain to avoid new deformations. Among the solutions considered were the construction of an absorption system with movement monitoring, or the relocation of the trace on the opposite bank of the river. It was decided to adopt the latter solution due to the difficulty of ensuring the stability of the terrain and the inaccessibility during the winter. It implied an additional river crossing and consequently, the need to monitor the stability of the channel to the river erosion.

Detailed studies performed to design works at river crossings provide all the information needed to asses hydro technical hazards. TGN performed such studies for critical rivers as part of its Integrity Management Program. By monitoring performance of remediation works, experience was built throughout 10 years comprising different hydrological years. This was the base for the development of a simpler methodology aimed at assessing risk using information that can be readily available in regions such as Latin America where the existence of gaging stations and historic records at most rivers are not common. The method is based in river geomorphology, summarized with two parameters: area of drainage basin area and river slope at the crossing. They characterized the type of problems that can be expected and they can be estimated from topographic maps or digital terrain models available from the internet. The rating method follows a basic structure consisting in the product of two factors: causes and consequences. Causes include: bank erosion, river bed scour, meanders and river diversion along the right of way. Then, increasing factors are applied accounting for deforestation, land use and the occurrence of debris flows; decreasing factors consider proper remediation works, design and construction aspects implemented during construction. Finally, consequences are focused at loss of human life, impact on the environment, and interruption of fluid transport. This method is aimed to be performed by a pipeline operator that can have a good feeling of problems related to rivers, without having the technical knowledge of a specialized consultant. While rating, subjective judgment still plays an important role. However, this methodology provides a systematic approach that includes all aspects affecting river crossings, allows for prioritizing works based on rates and, as new rivers are included from new watersheds, it can be improved as prediction and characterization tool.

The experience gained during the operation and maintenance stages of the Camisea pipeline transportation system (STD) in Peru, crossing from the Tropical jungle in the Cusco region to the coast, in Lima city, has enabled us to develop and apply techniques in construction and maintenance works focused on controlling of the vertical undermining of riverbeds and the erosion of margins at river crossings and creeks crossed by the pipeline carrying NG and NGL. According to the above, a technical assessment study was conducted of the crosses rivers and creeks that have high priority of the Camisea pipeline path, comprising — among other disciplines — hydraulic and undermining analysis, as well as an hydrologic and geo-morphological evaluation and other issues regarding general geology and geo-techniques at each crossing site. A work program was developed using the information obtained in the three sectors travelled by the (STD) in order to develop and complement works at the crossings of rivers and valleys aiming to protect the integrity of the pipeline from erosion produced by major and extraordinary floods in riverbeds and alluvial slides in narrow valleys, by means of confinement and sedimentation works. The jobs performed in rainforest, mountain and coastal terrain crossed by the pipeline considered different river morphology types — being the most common the straight, gravel braided and curved river travels — and regimes in both flow speed and width of the riverbed. From the topographic follow-up and monitoring stage on — before and after the rain season — at crossings beneath the riverbeds, it was determined that the deterioration process affecting the crossing stripe corresponds to erosion consisting in the alteration of the watercourse banks that affects the piping foundations. The works are completed considering the type of resources available at the site of the river crossing — i. e., the engineering is particular to each sector, and designing is performed upon available materials in the area. The most utilized works at river and creeks crossings on the Camisea piping system are as follows: i) protection of riverbeds and creeks slopes using gabion mesh and pads; ii) sedimentation systems on gabion mesh; iii) Energy dissipation devices at creeks crossings; iv) rip-rap –type armoring of riverbeds; v) confinement check dams ; vi) marginal protection dikes; vii) marginal protection rock fill dams; viii) protection and sedimentation breakwaters, among others.

Linear works, such as highways, power lines, gas and oil pipelines among others, as well as other types of engineering works can be threaten by natural hazards, such as landslides, floods, erosions, earthquakes, hurricanes, seaquakes and others, which could lead to great environmental impacts, very high sum of money lost and even deaths. Aiming to reduce geological and geotechnical risks, preventive or corrective actions can be executed from the design phase to the operational and maintenance stages in pipelines. In this last phase, an integrity management plan of these facilities can be adopted, with the purpose of mitigating residual risks that had not been covered on the design and construction phases. One of the alternatives to implement an integrity management of gas pipelines is found in the code “Managing System Integrity of Gas Pipelines” – ASME B31.8S (2005). However, this code has some limitations in actions concerning to prevention, identification and correction of geological and geotechnical problems. This paper presents information about geotechnical risks in transmission pipelines and tools applied in identification, prevention and correction of geotechnical problems in pipelines, as well as, others with potential to be applied in pipelines. A basic pipeline integrity management plan focused in geotechnical risks is proposed in the paper, transcribed as a contribution to ASME B31.8S Code. This plan is composed by actions: from identification, prevention, evaluation and analysis to correction of geotechnical instabilities in pipelines. The plan is composed by a flowchart with all actions selected for the geotechnical risk care. The plan was developed based on directions set in ASME B31.8S Code, together with Brazilian, Italian and Canadian experiences.

As of the date this paper is written pipelines in South America comprises 113000 kms of transmission lines including Oil, Gas, Condensates, and refined products from which approximately 17% (19400 kms) crosses the Andes reaching elevations up to near 5000mts. Rugged terrain combined with the geology, weather conditions (especially rain intensity) and continuous pipe ruptures in the past impose serious challenges for the pipeline industry that makes the design, construction and operation substantially different from other pipelines in the world. The records have shown that the threat of Ground movement/weather-related pipeline ruptures in the Andes plays a significant role since the percentage of the risk associated with geotechnical causes is substantially higher than any other parts such as Europe or United States. Thus the rate of pipeline failures due to natural forces is significant higher than the average industry. Peru LNG is a 406km × 34in gas pipeline transporting natural gas from the jungle side of Peru to the Pacific Coast where a LNG terminal has been installed. Peru LNG’s pipeline currently holds the record of being the highest Gas Pipeline of the world with a maximum elevation of 4901 meters above sea level. Project completion was done in May 2010 and lessons learnt from similar projects were taken into account since project designs. This paper is divided in two parts. First, it compares pipeline ruptures frequencies due to natural forces in the Andes with other pipelines in different terrains based on historical cases compiled by the authors. Secondly, it explains the different phases of Pipeline Project in rugged terrain from the conceptual design until the operations stage and the role of Pipeline Geotechnical Engineers in this process based on PERU LNG’s pipeline experience. It also describes some of the main features of the PLNG pipeline project. A comprehensive flow chart provides general guidance for future pipeline projects in similar conditions.