Many pipelines are built in regions affected by harsh environmental conditions where changes in soil texture between winter and summer increase the likelihood of risks. Pipeline routes also cross the mountains that are characterized by steep slopes and unstable soils as in the Andes and along the coastal range of Brazil. In other cases, these pipelines are laid in remote areas with significant seismic activity or exposure to permafrost. Depending on weather conditions and location, visual inspection is difficult or even impossible and therefore remote sensing solutions for pipes offer significant advantages over conventional inspection techniques. Optical fibers can help solve these challenges. Optical fiber based geotechnical and structural monitoring use distributed measurement of strain and temperature thanks to the sensitivity of Brillouin scattering to mechanical and thermal stresses. The analysis of scattering combined with a time domain technique allows the measurement of strain and temperature profiles. Temperature measurement is carried out to control soil erosion or dune migration through event quantification and spatial location. Direct measurement of strain in the soil also improves the detection of environmental hazards. As an example the technology can pinpoint the early signs of landslide. In some cases, pipe actual deformation must be monitored such as in case of active tectonic fault crossing. Pipe deformation monitoring operation is achieved by the measurement of distributed strain along fiber sensors attached to the structure. This paper comprehensively reviews over 10 years of continuous development from technology qualification and validation to its implementation in real cases as well as its successful continuous operation. Case studies present pipeline monitoring in Arctic and Siberian environment as well as in the Andes. They illustrate how the technology is used and demonstrate proof of early detection and location of events such as erosion, landslide, subsidence and pipe deformation.

The 408 km × 34" PERULNG pipeline (operated by Hunt LNG Operating Company) is monitored in its first 62 km by a geotechnical fiber optic cable, since these first 62 km are exposed to major geohazard threats such as landslides, large river crossings, high slopes, bofedales, etc. The fiber optic cable geotechnical monitoring relies on the measurement of strain and temperature in the pipeline right-of-way. Due to the continuous and real-time monitoring of the duct, it was possible to detect a tension cracking near KP 25 + 600 as an abnormal temperature change was captured by the temperature sensing cable; also near KP 27 + 900 and KP 34 + 750 unusual cable stresses were detected which announced landslides of the rotational type in both locations. In these three cases, protection decisions could be taken to secure pipeline’s integrity.

In slope movements with slow strain rates that affect rights of way (ROW) or its surrounding areas, an appropriate Inline Inspection (ILI) program with inertial modules may provide timely and quality information, with ease of matching with geotechnical events and lower costs than conventional monitoring methods. In virtue of above, for structural integrity management of pipeline, this information is necessary and its integration with the information obtained from other sources such as ROW patrol, terrain monitoring and pipeline monitoring. This document contains information related to the tracing, analysis and executed activities in the study case located in Colombian center-west, where neotectonic effects and a common ROW with a main highway converged.

The present paper presents the analysis, carried out by the Ocensa pipeline, against a case of longitudinal or axial landslide to the pipeline in the KM 35 + 690, starting from the identification by inertial tool, the geotechnical characterization and the analysis of Soil-pipe interaction, excavation and stress relief and the techniques used to mitigate the effects of sliding on the pipe.

Unmanned aerial vehicles (UAV), also known as drones, have become a very reliable and convenient tool to many engineering applications. Pipeline corridors are often exposed to geotechnical risk that may interrupt proper service. The risk sources vary, and range from steep hills to many site conditions such as ancient landslides, changes on phreatic water level, creeping soils, or geomorphological changes on the environment. Knowing and understanding the level of risk is highly dependent on identifying any geotechnical hazard in due time, before it materializes. Pipeline corridors are measured in kilometers, and the area that may adversely affect the corridor can vary from a few meters to several hundred on each side of the corridor. This paper presents an application of UAV based digital photogrammetry to evaluate and monitor the hazard and evolution of the site PK 469 OCENSA km 149 ODC. The site is maintained by Oleoducto Central S.A. (OCENSA), and the paper describes the different geotechnical studies and works carried out to maintain uninterrupted service of the pipeline. The paper includes technical information supporting the processing and characteristics of the photogrammetry based evaluation and monitoring method, to highlight the efficiency and accuracy of the proposed method.

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.

Employing published information and sharing monitoring apparatus and studies, were the initial solution adopted to reach a rain monitoring process in Transpetro (Petrobras Transporte S.A.) southern ROWs. This type of approach can be easily establish and allows the operator to reach satisfactory results, especially for those that has no controlled process at all, where a small amount of information leads for some result even if it is to clarify the need and the resources for such kind of approach. Even being quite conservative and bit superficially, the process recently established in Transpetro, has already brought a slight economy and safety. Aiming to show the process flow, this paper does not concentrates in reflecting the trigger point, instead it reflects the experience and general methods applied for checking forecasts and rainfall index.

The Camisea’s Pipeline Transportation System (PTS) in Peru, owned by Transportadora de Gas del Perú (TgP) and operated by Compañía Operadora de Gas del Amazonas (COGA), stars in the Amazon rainforest, crosses the Andes Mountain (4850masl) and descends finally towards the coast of the Pacific. The PTS has more than 10 years of operation and it has two pipelines: one transports Natural Gas (NG) and the other Natural Gas Liquids (NGL) pipelines. The NG pipeline has a length of 864km including a Loop pipeline of 135km. The NGL pipeline has a length of 557km. Because of particular physiographic conditions of each geographic sector that cross the right-of-way (ROW), the integrity of the PTS acquires a level of significant susceptibility to the occurrence of geohazard, which are the product of natural erosive processes and mass movements. In the coast sector, one of the most representative processes of geotechnical instability is the soil or debris flow (mass movements of soils). The occurrence of this type of flow has a greater incidence in the torrential creek, which generate transport of large volumes of sediments during rainy seasons. The flow has destructive effects and therefore, it is necessary to analyze the geomorphological, geological and hydrological aspects of the main creek and rivers that crosses the ROW with the objective of maintaining the integrity of the pipelines. In Peru, the flows are associated and known as Huayco or Huaico. As an additional component, it is highlight that the Peruvian coast is located within the area of interaction between the South American Continental Plate and the Nazca Plate, where there is evidence of seismic activity with different magnitude that influence on the occurrence of geo-dynamic processes with certain periods of frequency that could change the terrane’s morphology. The current article describes technical aspects of identification, intervention, monitoring, and geotechnical control in sub-fluvial crossings with levels of potential damage to the geohazard defined as huayco in the integrity management program of PTS. This activity include 63 main sub-fluvial crosses, approximately 30% are of the seasonal flow regime, located in the coast zone; at the same time, these are tributary to main rivers of constant flow as is the case of the Pisco, Cañete and Mala rivers. In this paper, it is place a special emphasis on the fourth crossing of the Huáncano creek, because it is a place of potential impact in the occurrence of soil flows. Within the annual geotechnical maintenance of the sub-fluvial crosses, in the part of the Peruvian coast, for the operation of the PTS of TgP, bed and banks protection some works are implemented, such as: Check dams, re-channeling, levees and stone riprap (Stone armour). Likewise, a program of evaluation and technical inspection is develop: it includes the analysis of the expected levels of undermining and performance condition of the existing works, which allow defining the geotechnical intervention in a term according to the identified risk level. All in all framed within a process of permanent geotechnical monitoring of the right of way. Finally, it is highlighted that to date the application of the process described above has been continued, which has facilitated the development and continuous assessment of the risk condition by huaycos in the PTS of TgP. This program has maintained an operation with an acceptable level of risk in the areas of interest and avoiding problems and consequences of great impact to communities, the environment and the operation of the system.

The OPASC and the OSPAR are 10″ and 30″ pipelines, respectively, which interconnect the State of Santa Catarina and Paraná, crossing the Serra do Mar, in southern Brazil. In 2003, after conducting slope stabilization works on a point of geotechnical activity, vibrating string gauges were installed to monitor the stress in these pipelines, in addition to geotechnical instruments installed to monitor the slope. These gauges were installed in seven sections, with 3 instruments per section, along a span of 180 meters. Although the geotechnical instrumentation has shown no evidence of movement in the slope, the gauges recorded an increase in stress values in some of the sections within three months from the time of installation, however, they remained stable in their values for the next ten years. In 2013, blind hole tests were performed to determine the stresses in these sections and to verify the proper function of the gauges. The combination of these two measurement techniques, vibrating string gauges and blind hole tests, allowed for the determination of the stress state in sections, over time. From there, equivalent stress could be determined and compared with allowable stresses defined in standards. After the completion of the blind hole test and subsequent backfill, stress rose again at the same rate, returning to the level reached after the initial installation of the strain gauges. To reduce the stress level additional excavations have been made to relieve the stress on the pipeline, followed by backfilling performed in a controlled manner in order for the soil to properly compact, which reduced the stress value over the pipes. The graphs depicting variation over time of stress showed a significant reduction in the level of stress after the backfill. The main conclusions are listed as follows: a) the evolution of stress observed by the extensometers was primarily caused by pipeline settling; b) the vibrating string gauges are functioning properly and provide reliable readings even after ten years of service; c) the blind hole testing performed in conjunction with monitoring by vibrating string gauges can provide approximate values of the full stress state; d) after stress relief, backfilling of the trench must be carried out by compacting the soil beneath the pipe in order to reduce bending stresses due to the weight of the soil; e) backfilling of the trench, when not properly performed, can cause compressive stress in bending, reaching 390 mPa over the next few months.

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.

ECOPETROL S.A. has been working since 2006 in Pipeline Integrity Management Process. In that process, the threat related to climate and external forces play an important role, because of the vulnerability of ECOPETROL pipelines to this threat, not only by the geomorphology of Colombia, but also because of the strong impact of climate phenomenon such as “La Niña”, that consists in an unusual quantity of rain precipitation, represented in the increasing of slopes instability that affects the rights of way. Due to these events and the evolution of optical strain sensors monitoring technology, ECOPETROL has introduced an instrumentation pipeline program for monitoring the strain and advanced in the understanding of the behavior of pipelines. This paper describes the technology selected, the criteria used to select the monitoring sites and the thresholds stress/strain. The results of monitoring are discussed for a particular case.

One of the major concerns for pipeline operators is to efficiently monitor the events happening over the pipeline corridor, or right-of-way (ROW). Monitoring of the ROW is an important part of ensuring the safe and efficient transportation of oil and gas. Events occurring within this zone require rapid assessment and, if necessary, mitigation. These events could be physical intrusions such as encroachment from growing settlements, impact of vegetation, pipeline leakage or geo-environmental hazards. Analysis of satellite imagery can provide an efficient and low cost solution to access and quantify change across the ROW. Examining these events over a periodic interval requires implementation of specific methods that can support the on-going monitoring and decision making practices. In this context, satellite remote sensing images can provide a low cost and efficient solution for monitoring the physical and environmental impacts over the ROW of pipeline system. This paper reports on the development of a methodological approach for environmental change analysis using high resolution satellite images that can help decision making in pipeline systems. Analysis results and maps produced during this work provide an insight into landcover change over the study area and expected to support in on-going pipeline management practices. Two methods, Vegetation index differencing and post classification comparison have been implemented to identify change areas in the Taranaki region of the North Island of New Zealand. Vegetation index differencing with NDVI shows increase or decrease of overall vegetation within the study area. Special focus was given on large area increase and decrease with area threshold value above 0.2 hectare. Detailed analysis of change was conducted with post classification comparison method that uses land cover classification results of year 2010 and 2013. An overall change of 10% has been observed throughout the study area with large area change of approximately 5%. Results obtained from post classification comparison method were further analyzed with 6 focus areas and compared with the existing soil data and rainfall data. The methods adopted during this study are expected to provide a base for environmental change analysis in similar pipeline corridors to support decision making.

Petrobras Transporte S/A – TRANSPETRO – is the largest natural-gas processing company in Brazil and holds the leading position in fuel transportation and logistics in the country. The 14,000-km pipeline network, like other civil transportation infrastructure, crosses a huge variety of geological-geotechnical terrains, including those susceptible to natural hazards. The OSBAT right-of-way, which belongs to TRANSPETRO’s pipeline network, has become the object of study in this paper because some sections along the right-of-way have installed geotechnical instrumentation that indicates creep movements, which have been acting continuously for decades. Due to the importance of the OSBAT pipeline, a bibliographic review to support the development of limits for displacement velocity of slope shearing zones was concluded to assist the department responsible for evaluating when atypical behavior in the historical displacement data occurs. This geotechnical warning, allied with field and in-line inspections, will improve the pipeline risk management program. The limits for inclinometers were established using T-Student statistical analysis from a reading database based on geotechnical field inspections. However, direct correlation with pipe strain was not verified due to small accumulated displacements.

The principle of redundancy in the analysis of pipeline integrity has taken on particular significance in recent years, thanks to the integration and relating of information obtained from various sources, which include, smart pig runs, visual right-of-way inspections and monitoring of the land and the pipeline. This document contains information related to the monitoring and analysis prior to emergency actions taken in the case study presented, located in northeast Colombia, where the effects of mining activity and excess rain during the winter period of 2010–2011 combined. The integrity information available with regard to background, visual right-of-way inspection, threat and risk assessments, direct monitoring of the pipeline and the analysis of deformation by bending, which Ecopetrol’s Office of Vice-president for Transportation and Logistics (VIT) made at the site, was taken into account. In addition, it includes a description of the interrelationship of such information, the findings in the activities conducted during the attention to the site, for the purpose of identifying the evidence related to external loads exerted by the land in the soil-pipeline interaction, which made it possible to better determine the proposed plan of action. The redundancy in the analysis of this information makes it possible to more accurately determine the root cause of the problem, the interaction between the phenomenon (external load - geotechnical event) and the pipeline, by which attention was directed in the field and action plans were obtained that better mitigate the threat and guarantee more safe and reliable operation.

The effects of changes in land use and the effects of climate change have led to an increase in the morphodynamic processes that affect rights-of-way in Colombia. However, in view of the fact that these rights-of-way are considered to be the best possible routes in some areas in which the geological and geotechnical components are fairly complex, specialists are facing the challenge of establishing different perspectives for coexisting with the geohazards in these areas. This paper describes the analytical methodology implemented within Ecopetrol’s Office of the Vice President for Transportation and Logistics (VIT-Ecopetrol), in order to take this reality into account within the framework of proper asset management.

By their nature, Pipeline Transmission Systems are exposed to threats from various sources. These include the threat of Weather and Outside Forces (WOF), this threat has a destructive potential associated with landslides, creeping, soil erosion and scouring in rivers, etc. Their hazards increase when pipelines are installed in areas with a tropical climate, having rains of a magnitude that often tend to destabilize the soil surrounding the pipelines, affecting its integrity and therefore the safety of people and the environment. The identification and monitoring of geotechnical risk areas, using inertial data, is based on the reprocessing and analysis of the raw data provided by in line inspection tools. The result of this analysis, after the noise reduction process using a variety of filters at different intervals, reveals areas where there is possible deformation. These zones are transformed into indications that are studied by an analyst, correlating other data sources such as terrain topography, soil characteristics, hydrology, ground motion records, ILI records (caliper records, MFL records, etc.), as-built data, stress concentrators, etc. The analyst determines if they are pipeline deformations due to soil movement or if the indication is caused by another source such as the noise caused by the electronic components of the tool, the operating conditions during the inspection, the filtering process, etc. Areas with signs of strain are evaluated to determine the tensional state in critical conditions for each specific case. If the stresses are close to the limits, a field inspection and an action plan are needed for each case. In certain cases, according to the experts, field indications are evaluated to verify the data obtained by the ILI Tool and to simultaneously give feedback to the noise reduction process. The execution of the calculation process allows the monitoring and identification of geotechnical risk areas, providing better control over parameters such as limits for reporting indications, control of discrimination and selection criteria, detailed assessment of each indication, etc. Finally, this process provides the opportunity to obtain additional information from the ILI inspection such as unregistered bending, misaligned welds, areas with excess root welding, etc.

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.

Gasoducto del Pacífico is a pipeline that carries natural gas from southern Argentina to Chile, through the Patagonian Andes. During previous years of operation only minor sign of soil movement were registered by the monitoring program, taking the form of ditch settlements. However, on September, 2005 a landslide took place producing a gas leak, at a segment that was previously characterized as a non-critical one. An initial office review of available information and site pictures would not yield a clear reason of land movement initiation given the terrain mild slope. Actions were taken aiming at three different time frames. Immediate remedial actions were taken such as ditch opening to free stresses and replacement of buckled pipeline. Integrity specialist flew to the site to conduct geological survey and a stress analysis was conducted at a lab, allowing to asses and manage present risk before transportation began. Mid-term solutions were implemented as the ditch remained open until the next summer season, when access to the site was guaranteed. Finally, two new river crossings were constructed to mitigate this natural hazard permanently. Lessons from this incident revealed design aspects that need to be reconsidered to assure mountain pipelines integrity.

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.