Results of a Mitigation Technique Used to Reduce Pipeline Strains in Unstable Slopes

Author(s):  
Maria F. Contreras ◽  
Mauricio Pereira Ordoñez ◽  
Jon Hernández ◽  
Carlos Vergara

The OCENSA pipeline system crosses a wide range of geological zones, finding different stability problems. Those problems related with landslides are stabilized with different kinds of geotechnical works within the pipeline maintenance programs, but sometimes these problems reach big dimensions making very difficult to stabilize them, so mitigation techniques are necessary in order to guarantee the pipe integrity. A mitigation technique using EPS (Expanded Poly-Styrene) blocks is being used in the OCENSA pipeline system (Colombia) in order to reduce the buried pipe response due to soil displacements during landslide events and in creeping slopes. OCENSA is the first operator in Latin America using this technique. Prior to the use of this technique, numerical modeling studies were done with the support of SOLSIN S.A.S. These studies were focused on determining the viability and effectiveness of the proposed technique. The purpose of the EPS blocks is to constitute a low-density fill with very low Young modulus reducing the soil-pipeline interaction forces. These blocks are located near the landslide limits in both, the stable and un-stable zones in order to reduce the stiffness of the materials around the pipe. These blocks allow the pipe to move beyond the landslide limits, reducing the bending strains. The extension of the EPS backfill is determined by means of the geotechnical investigation of the place in study and using the in-line inspection tools data to determine the length of the pipe affected by the soil movement. In this paper, three case studies are presented in which the proposed mitigation technique effectiveness was proved. In this part, data analyses coming from the in line inspection program was done. The inertial tool data showed that the EPS blocks had a significant effect on the pipe response, reducing the total strains compared with those obtained with a normal backfill. This technique can be used to reduce the frequency of the strain-relief excavations in unstable slopes. That means a cost reduction in the pipe maintenance activities and a more efficient integrity management program.

Author(s):  
M. Robb Isaac ◽  
Saleh Al-Sulaiman ◽  
Monty R. Martin ◽  
Sandeep Sharma

In early 2005, Kuwait Oil Company (KOC) initiated a Total Pipeline Integrity Management System (TPIMS) implementation in order to carry out a major integrity assessment of its operating facilities, equipment, buried plant piping and pipeline network and to establish a continuing integrity management program. KOC Transit System is a complex infrastructure consisting of over three hundred pipelines, thousands of wellhead flow lines, and consumer and offshore lines for which there was a significant loss of data when the facilities were destroyed during a military invasion in 1990. An initial pipeline system assessment identified issues and actions regarding condition of the pipelines, corridors, requirements on in-line inspection (ILI), documentation, RISK assessment, status of international code compliance, and overall state of the system. Following recommendations from that initial assessment led to the development of a long term strategy; the execution of which required the implementation of a comprehensive integrity management program. This case study discusses the results obtained after five years of implementation of TPIMS at KOC. It will demonstrate some of the complex components involved in managing the integrity of the Transit System that have been made possible through the implementation of the system. The general concept and structure of TPIMS will be described, and how it deals with the complexity of the KOC pipeline system. The system made it possible to integrate and manage data from various sources, by conducting integrity assessment using ILI, Direct Assessment and hydrostatic testing, as well as structure a comprehensive RISK & Decision Support mechanism. This is one of the world’s first implementations of this magnitude which encompasses such a wide range of services and variables; all being managed in a single environment and utilized by a multitude of users in different areas at KOC. The biggest challenge in a project of this scope is data management. Examples will be shown of the integration structure to illustrate the benefits of using a single comprehensive and versatile platform to manage system requirements; ultimately providing system reliability and improving overall operational efficiency.


2010 ◽  
Vol 26 (02) ◽  
pp. 106-110
Author(s):  
Ge Wang ◽  
Michael Lee ◽  
Chris Serratella ◽  
Stanley Botten ◽  
Sam Ternowchek ◽  
...  

Real-time monitoring and detection of structural degradation helps in capturing the structural conditions of ships. The latest nondestructive testing (NDT) and sensor technologies will potentially be integrated into future generations of the structural integrity management program. This paper reports on a joint development project between Alaska Tanker Company, American Bureau of Shipping (ABS), and MISTRAS. The pilot project examined the viability of acoustic emission technology as a screening tool for surveys and inspection planning. Specifically, testing took place on a 32-year-old double-hull Trans Alaska Pipeline System (TAPS) trade tanker. The test demonstrated the possibility of adapting this technology in the identification of critical spots on a tanker in order to target inspections. This targeting will focus surveys and inspections on suspected areas, thus increasing efficiency of detecting structural degradation. The test has the potential to introduce new inspection procedures as the project undertakes the first commercial testing of the latest acoustic emission technology during a tanker's voyage.


Author(s):  
Garry L. Sommer ◽  
Brad S. Smith

Enbridge Pipelines Inc. operates one of the longest and most complex pipeline systems in the world. A key aspect of the Enbridge Integrity Management Program (IMP) is the trending, analysis, and management of data collected from over 50 years of pipeline operations. This paper/presentation describes Enbridge’s challenges, learnings, processes, and innovations for meeting today’s increased data management/integration demands. While much has been written around the premise of data management/integration, and many software solutions are available in the commercial market, the greatest data management challenge for mature pipeline operators arises from the variability of data (variety of technologies, data capture methods, and data accuracy levels) collected over the operating history of the system. Ability to bring this variable data set together is substantially the most difficult aspect of a coordinated data management effort and is critical to the success of any such project. Failure to do this will result in lack of user confidence and inability to gain “buy-in” to new data management processes. In 2001 Enbridge began a series of initiatives to enhance data management and analysis. Central to this was the commitment to accurate geospatial alignment of integrity data. This paper/presentation describes Enbridge’s experience with development of custom software (Integrated Spatial Analysis System – ISAS) including critical learnings around a.) Data alignment efforts and b.) Significant efforts involved in development of an accurate pipe centreline. The paper/presentation will also describe co-incident data management programs that link to ISAS. This includes enhanced database functionality for excavation data and development of software to enable electronic transfer of data to this database. These tools were built to enable rapid transfer of field data and “real time” tool validation through automated unity plots of tool defect data vs. that measured in the field.


Author(s):  
Len LeBlanc ◽  
Walter Kresic ◽  
Sean Keane ◽  
John Munro

This paper describes the integrity management framework utilized within the Enbridge Liquids Pipelines Integrity Management Program. The role of the framework is to provide the high-level structure used by the company to prepare and demonstrate integrity safety decisions relative to mainline pipelines, and facility piping segments where applicable. The scope is directed to corrosion, cracking, and deformation threats and all variants within those broad categories. The basis for the framework centers on the use of a safety case to provide evidence that the risks affecting the system have been effectively mitigated. A ‘safety case’, for the purposes of this methodology is defined as a structured argument demonstrating that the evidence is sufficient to show that the system is safe.[1] The decision model brings together the aspects of data integration and determination of maintenance timing; execution of prevention, monitoring, and mitigation; confirmation that the execution has met reliability targets; application of additional steps if targets are not met; and then the collation of the results into an engineering assessment of the program effectiveness (safety case). Once the program is complete, continuous improvement is built into the next program through the incorporation of research and development solutions, lessons learned, and improvements to processes. On the basis of a wide range of experiences, investigations and research, it was concluded that there are combinations of monitoring and mitigation methods required in an integrity program to effectively manage integrity threats. A safety case approach ultimately provides the structure for measuring the effectiveness of integrity monitoring and mitigation efforts, and the methodology to assess whether a pipeline is sufficiently safe with targets for continuous improvement. Hence, the need for the safety case is to provide transparent, quantitative integrity program performance results which are continually improved upon through ongoing revalidations and improvement to the methods utilized. This enables risk reduction, better stakeholder awareness, focused innovation, opportunities for industry information sharing along with other benefits.


Author(s):  
Robert V. Hadden ◽  
Kevin J. De Leenheer

As part of its Integrity Management Program, Trans Mountain Pipe Line hydrostatically tests sections of its pipeline system with water transported to test sites through the pipeline. After completion of the testing, the water continues through the pipeline to a water treatment facility where it is treated and discharged to the municipal sewer system. Hydrostatic testing of an operating pipeline, although simple in concept, is a major undertaking. This paper will outline the technical aspects of Trans Mountain’s hydrostatic testing program including: test water transportation, environmental constraints, coordination of test activities and water treatment.


Author(s):  
Hugo García ◽  
Carlos Nieves ◽  
Juan Diego Colonia

Oil pipelines systems for hydrocarbons transportation are linear projects that can reach great lengths. For this reason, theirs paths may cross different geological formations, soil types, navigable or torrential waters; and they may face geotechnical and hydrological instability problems such as creeping slopes, geological faults, landslides, scour and differential settling which causes different relative movements between the soil and the pipeline. The OCENSA (Oleoducto Central S.A) 30″ and 36″ diameter system was built in 1997 to transport crude oil from the eastern foothills of the Andes to the Caribbean Coast along some 830 km of the Eastern Andes mountains range and the spurs of the central Andes mountains range of Colombia: it was a major challenge to secure the integrity of the pipeline in the face of natural events.


Author(s):  
Miaad Safari ◽  
David Shaw

Abstract As integrity programs mature over the life of a pipeline, an increasing number of data points are collected from second, third, or further condition monitoring cycles. Types of data include Inline Inspection (ILI) or External Corrosion Direct Assessment (ECDA) inspection data, validation or remediation dig information, and records of various repairs that have been completed on the pipeline system. The diversity and massive quantity of this gathered data proposes a challenge to pipeline operators in managing and maintaining these data sets and records. The management of integrity data is a key element to a pipeline system Integrity Management Program (IMP) as per the CSA Z662[1]. One of the most critical integrity datasets is the repair information. Incorrect repair assignments on a pipeline can lead to duplicate unnecessary excavations in the best scenario and a pipeline failure in the worst scenario. Operators rely on various approaches to manage and assign repair data to ILIs such as historical records reviews, ILI-based repair assignments, or chainage-based repair assignments. However, these methods have significant gaps in efficiency and/or accuracy. Failure to adequately manage excavation and repair data can lead to increased costs due to repeated excavation of an anomaly, an increase in resources required to match historical information with new data, uncertainty in the effectiveness of previous repairs, and the possibility of incorrect assignment of repairs to unrepaired features. This paper describes the approach adopted by Enbridge Gas to track and maintain repairs, as a part of the Pipeline Risk and Integrity Management (PRIM) platform. This approach was designed to create a robust excavation and repair management framework, providing a robust system of data gathering and automation, while ensuring sufficient oversight by Integrity Engineers. Using this system, repairs are assigned to each feature in an excavation, not only to a certain chainage along the pipeline. Subsequently, when a new ILI results report is received, a process of “Repair Matching” is completed to assign preexisting repairs and assessments to the newly reported features at a feature level. This process is partially automated, whereby pre-determined box-to-box features matched between ILIs can auto-populate repairs for many of the repaired features. The proposed excavation management system would provide operators a superior approach to managing their repair history and projecting historical repairs and assessments onto new ILI reports, prior to assessing the ILI and issuing further digs on the pipeline. This optimized method has many advantages over the conventional repair management methods used in the industry. This method is best suited for operators that are embarking on their second or third condition monitoring cycle, with a moderate number of historical repairs.


Author(s):  
Neil Ripley ◽  
Elisa Scordo ◽  
Alex Baumgard

BGC Engineering Inc. (BGC) was retained by a large pipeline operator to develop a GIS-based system to assess and rank the environmental consequence of a pipeline rupture on watercourse crossings within their pipeline system. Several physical, biological and socio-economic factors contribute to the environmental consequence of a pipeline rupture on a watercourse. This study examined select spatial and vulnerability factors, and did not consider biologic or economic impacts. Three factors were selected as part of the initial study to prioritize the pipeline watercourse crossings according to: (1) size of the watercourse at the pipeline crossing, (2) proximity of each individual crossing to larger downstream watercourses, and (3) pipeline liquid flow rate volume. A spatial analysis was conducted to determine the first two factors, while input for the third factor was provided by the pipeline operator. Watercourse size was determined using Strahler’s stream order classification (Strahler 1952), while proximity to larger downstream watercourses was assessed using a Geographic Information System (GIS). This paper presents an overview of the data sources and methods used to develop an initial screening tool for identifying high consequence crossings within a pipeline system, and highlights the challenges encountered with acquiring and processing data to include in a consequence rating system. As with other pipeline risk assessments, the main challenges of this work include data availability, data integrity and resource limitations. This system is intended to fit within the pipeline operator’s current geohazard integrity management program and direct resources for a multi-year baseline field inspection program.


Author(s):  
Cory Wargacki ◽  
Wade Forshner ◽  
Rogelio Guajardo ◽  
Thomas Hennig

Abstract Axial cracking inspections have become common place on a global level within pipeline operator’s integrity management programs. As technology continues to improve, operators are presented with more accurate assessments of the assets that are in current operation. However as more information is collected more threats are being identified and need to be assessed in a manner that is more applicable to their specific morphology. It is well known that vintage ERW manufacturing techniques can suffer from a wide range of potential threats such as lack of fusion or inclusions within the steel forming hook cracks during the rolling and welding process. Current In-line inspection technologies that are designed to detect, Identify and size cracklike flaws in pipelines are very proficient at doing so. However, due to the physical principals of the Ultrasonic pulse echo technology, deep features approaching, or above pulse echo saturation amplitudes pose challenges in determining accurate depth sizing. In 2015 a Canadian pipeline operator determined the need to inspect one of their 16” assets for axial crack-like indications. During the analysis of this inspection data set, a number of saturated crack-like indications were reported. Saturated cracklike signals present a challenge to operators as they have to be considered in a conservative manner as 4mm or deeper which in turn leads to difficulties in the prioritization of resources associated with the excavation program. The operator approached NDT Global in 2017, after the release of NDT Global’s Enhanced sizing depth algorithm to reevaluate the features that were present in the previous crack inspection data set. Working together with the operator, NDT Global applied the Enhanced sizing methodology to all features of significance in the pipeline segment and compared the results to lab measurements and in field NDE measurements. The outcome of the reanalysis using the most up to date software algorithms utilizing enhanced sizing showed great benefits by increasing the accuracy of the crack depth sizing as NDT Global was now able to report full through wall depth sizing, however there were still some limitations on the ability to accurately size crack-like features as the primary threat is believed to be a result of hook cracks. As a final step in this program NDT Global was provided sample spools that were cut out of the pipeline segment to perform a pull testing campaign utilizing the newest crack detection technology that was specifically targeted towards accurately sizing tilted and skewed crack like features. The authors will briefly discuss the pipeline system and inspection campaign and in detail will discuss the benefits of using technology that has been developed to help pipeline operators better understand the threats in their integrity management program.


Author(s):  
Jeremiah Konell ◽  
Brian Dedeke ◽  
Chris Hurst ◽  
Shanshan Wu ◽  
Joseph Bratton

Abstract In preparation for the upcoming (currently in draft form) Recommended Practice (RP) on Dent Assessment and Management (API 1183) [1], Explorer Pipeline Company, Inc. (Explorer) has performed an internal procedural review to determine how to effectively implement the methodologies into their Integrity Management Program (IMP). Explorer’s pipeline system transports hazardous liquids and is comprised of over 1,800 miles of pipeline ranging in diameter from 3 to 28 inches. The majority of the system was installed in the 1970s, but parts of the system were also installed as early as the 1940s. The primary focus of this review and implementation into the IMP is in regard to performing and responding to in-line inspection (ILI) based integrity assessments. Prior to the development of API 1183, dent assessment and management consisted of following a set of prescriptive condition assessments outlined in the Code of Federal Regulations (CFR) Title 49, Part 195.452. In order to do this, pipeline operators required basic information, such as dent depth, orientation, and interaction with potential stress risers such as metal loss, cracks, gouges, welds, etc. However, in order to fully implement API 1183, additional parameters are needed to define the dent shape, restraint condition, defect interaction, and pipeline operating conditions. Many new and necessary parameters were identified throughout the IMP, from the very initial pre-assessment stage (new ILI vendor requirements as part of the tool/vendor selection process) all the way to defining an appropriate reassessment interval (new process of analyzing dent fatigue life). This paper summarizes the parameters of API 1183 that were not part of Explorer’s current IMP. The parameters are identified, and comments are provided to rank the level of necessity from “must have” to “beneficial” (e.g. can sound and conservative assumptions be made when a parameter is not available). Comments are also provided to explain the impact of applying assumptions in place of parameters. The table of identified parameters should provide a useful tool for other pipeline operators who are considering implementing API 1183 as part of their overall IMP.


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