This paper will present the results which demonstrate the accuracy of the technique in detecting and locating blockages in gas pipelines. In particular the results of these tests will show how the technique was able to detect pipeline features with background noise.

In order to optimize the monitoring of Shallow Internal Corrosion (SIC), a new detection device has been developed on the basis of Eddy Current (EC) technology. The sophisticated SIC tool provides not only the determination of the corrosion status and growth rate, it also enables one to gain detailed information about the internal diameter and shape, such as ovality and dents. Shallow defects of even minor sizes are detected for assessing the degradation process resulting from internal corrosion.

Here, an introduction to the SIC inspection technology is presented.

An insight into, and some examples of, how design, construction and as-built records can help manage the risks associated with pigging and integrity management, how poor records create difficulties and uncertainties, and how ILI can tell you more about pipeline construction.

Approximately 60% of the world’s gas, oil and product pipelines can be inspected with off-the-shelf inspection tools. In the past the remaining 40 % of pipelines have often been classified as ‘unpiggable’. A large proportion of these unpiggable pipelines are offshore, multi-diameter lines, with low flow conditions and often with very challenging OD ratios.

Today, it is possible to develop individualized inspection solutions for multi-diameter pipeline systems. The development of such solutions can already be incorporated into the FEED process for these offshore structures. On the other hand, a great number of pipelines were constructed and laid in times when in-line inspection (ILI) was not available or not a requirement. Occasionally the passage of these offshore pipelines is restricted.

This paper presents the development of a series of 14"/18" ILI tools and their successful application survey in a 95 km long, high-pressure, heavy-wall, low-flow off-shore pipeline. In a team-effort between the pipeline operator (“Operator”) and the inspection company (ROSEN) a solution was developed for a challenging pipeline, which would have been considered ‘unpiggable’ in the recent past.

Pipesurvey International has developed a tool that can cover at least a bulk part of these pipelines. The XHR MFL tool incorporates all features of any up-to-date MFL ILI tool. The surplus value of the tool is that it is of complete bidirectional design, multidimensional and it has short bend-radius capability. The tool can be launched into a single-entry pipeline, be retrieved back at the same point and in the mean time inspect any length of pipeline. The tool is autonomous but can be operated with an umbilical as well. It is possible to combine the tool with a self propelling pipe robot, which takes the inspection range even one step further.

Intelligent pig inspection systems are important tools to manage the integrity of the pipelines. An intelligent pig survey enables the operator responsible for the integrity of the pipeline, to assess the failure risk due to metal loss corrosion using the findings of the inspection survey. However, not all pipelines can be inspected using intelligent pig technology, due to the pipelines origin. In addition the inspection results are not directly available during the inspection process and therefore important decisions can not be made until the inspection report has been issued in a later stage.

This paper discusses specific applications for offshore pipelines.

The paper will include an analysis of pipeline features that affect pigging tool selection and then go on to look at other variables that determine the pigging tool design; this will include a step by step guide outlining how the tool is designed, the development of prototype pigs and the importance of testing and validation prior to final deployment in operational pigging programmes.

The proper use of many of these methods can substantially reduce the costs of repair and maintenance programmes. Weatherford’s long experience suggests that most pipeline operators have their own well-grounded preferences for selecting methods to rehabilitate pipelines based on Fitness-For-Purpose assessments. As a rule, analysis of the current condition of pipelines requires that additional factors such as defect growth rate, interaction of adjacent defects, as well as pipeline operators’ specific requirements are taken into account almost all the time. The efficiency of defect assessment methods significantly increases when the results of two or more inspections are used. It has become desirable that the pipeline integrity assessment, which is a multi-stage process, would benefit from automation.

This paper describes Weatherford’s i-View℠ ILI software, which is the result of long experience of dealing with different pipeline operators.

Retrofitting pig launching equipment can also be extremely costly, particularly if the number of launches required are relatively few. There are also many cases where temporary launchers are required, yet these have even fewer available standards to work to.

International Pipeline Products Ltd of Catterick Garrison, UK have developed a solution that allows straightforward, temporary and cost effective pig launching and receiving for low pressure functions. Adding to the cost effectiveness of the product is the fact that the mechanism relies not on a pipe I/D but a pipe O/D, which, considering how it is usually the O/D that is constant in the pipeline to ensure standardised clamps and stands vastly increases the range of applications for each individual product across a pipeline.

In general these systems are set up prior to the pig run at which point signal frequency is selected relative to the type of tracking required. As a general rule a higher frequency is required to track pigs moving at a high velocity to ensure detection as the pig passes the detection unit. Lower frequency settings are utilized when a pig is to be monitored in a fixed location for a greater period of time. With the exception of radio active sources, battery life for the transmitters is almost directly proportional to the frequency of the signal hence a higher signal rate will reduce battery life.

The TDW SmartTrack™ system was developed to overcome the limitations of these systems by introducing through wall communication which allows the transmitter signal frequency to be modified externally. The result is greater flexibility during operations, particularly where these operations require extended monitoring over longer periods of time or where the unit can be put into sleep mode then re-awakened when critical operations re-start.

The units will also uniquely identify each passing pig in multiple pigging operations, log data such as pressure, allowing real time monitoring through the pipe wall.

Codes and regulations contain limit state criteria to prevent buckles from happening during construction and in service; however, there is practically no acceptance guidance. In cases when buckles and wrinkles are identified, pipeline operators seek expert opinion.

The current industry thinking and research supports the use of advanced assessment techniques (beyond the depth-based rules). These enhanced assessment techniques make use of the detailed profile of a geometry anomaly. Such information is obtained from high-resolution geometry tools and other supporting information on the presence and severity of stress risers from ILI tools.

This paper describes how strain-based and stress-based assessment of geometric anomalies can be utilized to assess their significance and need for remediation. Examples are discussed to demonstrate application of the enhanced methods for the assessment of buckles.

An in-line inspection tool capable of reading and recording the magnitude and polarity of current supplied by cathodic protection has been developed and tested in both crude oil and refined product pipelines. The results show that CP currents can be quickly, accurately and efficiently gathered without access to the outside surface of the pipe. For difficult to access areas, CPCM™ Cathodic Protection Current Measurement in-line inspection provides for a reliable, cost effective, time saving way to monitor, validate, or trouble shoot a pipeline’s cathodic protection system.

Over the history of pipeline operations, increasingly sophisticated techniques have been used to make measurements. Magnetic flux leakage and ultrasonic tools can be used to make measurements of wall loss, and other conditions. Caliper tools have been used to measure dents and other mechanical conditions. More exotic tools have been proposed from time to time. All of these techniques make a big contribution to allowing evidence-based decisions on the maintenance and rehabilitation of pipelines to be made.

It has been recognised in the industry that direct measurement of stress in pipelines could be a major tool in toolkit used for pipeline condition assessment. In the relatively recent past, the only reliable means to measure stress were either destructive, or non-portable. Advances in the understanding of magnetic properties of metals, and their relation to stress have allowed a number of potential measurement techniques to be proposed. Many of these have been based on the Barkhausen effect, but other concepts, such as non-linear harmonics have also been investigated.

Weatherford’s Pipeline and Specialty Services group, working with ESR Technology, are in the process of developing a pig capable of measuring the absolute biaxial stress in pipelines, based on ESR's proprietary MAPS measurement system.

Today, many pipelines and the connecting risers are piggable and with the intelligent In-line inspection (ILI) tools flaws can be detected to monitor integrity and fitness-for-purpose. Different types of tools are needed to cover all possible flaws, such as metal loss, cracks, geometric anomalies and leaks. Nevertheless, despite all kind of measures, the riser is still a difficult section for inspection as it may have a very thick wall thickness or other obstructions, thereby reducing the effectiveness of such ILI tools, also their speed in risers is difficult to control.

This presentation focuses on the “unpiggable” risers where free swimming ILI tools cannot be used or are of limited use. Application of internal tethered ultrasonic tools is discussed for inspection of both crude oil and gas risers. Besides that, in the second part of this paper, also non-intrusive methods will be shown as a valid alternative to inspect risers and pipelines from the outside, even without removing marine growth. Today this can be done even at -200 m using ROV’s.

The presentation shows that each tool has a dedicated field of application. Operational aspects as well as expected results will be discussed, they are of benefit for all operators of platform risers in the oil and gas-industry operated in the North Sea and world-wide.

Previous papers have discussed how to manage an inspection project, and have given guidance on understanding the inspection report. In this paper we will look in more detail at the assessment of corrosion defects reported in a pipeline by an intelligent pig inspection, and, in particular, large defects or groups of defects.

At this point it is important to draw a distinction between:

i) the analysis of inspection data to identify defects, and
ii) the assessment of the defects and their implications for the integrity of the pipeline.

These are two separate tasks: the first is carried out by someone who is familiar with the inspection technology and understands what the recorded data (voltage levels for coil sensor MFL tools, or time delays for ultrasonic tools) indicates in terms of pipe wall metal loss or other possible features; the second requires an understanding of how pipeline defects are caused, and how they behave when subject to internal pressure or other loads.

Pipeline bending can have regional or local character. Both defect classes can be detected and analyzed with specific in-line inspection modules. The latest geometry sensors developed by ROSEN can be combined with proven inertial navigation systems. This combination improves sensitivity, repeatability and confidence when detecting pipeline bending strain while also taking into account the influence of strain around ID anomalies.

Repeatability is important to establish the reasons for increasing strain values detected at specific pipeline sections through in-line inspection surveys conducted in regular intervals over many years. Moreover, the flexibility resulting from a combination of different sensor technologies not only makes it possible to meet specific operator needs but also provides a more complete picture of the overall situation.

A HAPP consists of a brake unit, a seal unit and a cleaning head. The brake unit ensures that a pressure difference develops over the seal unit and the fluid transported in the pipeline is transformed into high-pressure jets cleaning the pipeline inner wall.

This highly efficient technology has great potential to be employed for numerous non-standard pigging jobs. As a consequence it enables pipeline operators to save capex and opex today required for complicated pigging programs.

In addition, advancements in electronic design have led to marked enhancements regarding axial and depth resolution. Combined with higher speed capabilities than previous generations of ultrasound tools, this has significantly extended the range of application, offering quantitative and high accuracy data for defect geometries not previously covered.

This paper will focus on and discuss the issue of resolution.

This paper describes a range of application focusing on the time and cost saving achieved by the operator whilst minimizing environmental impact.

In recently years, a number of companies have investigated techniques intended to utilize the dependence of the magnetic response of ferrous materials to applied stress in order to make direct measurements of stress. Most of these techniques have been based on the Barkhausen effect, but measurements based on other phenomena such as non-linear harmonics have also been looked at. This paper discusses the use of an alternative technique based on other magnetic properties that have been shown to allow derivation of a quantifiable relation between the level of stress present in material and the magnetic response. This technique, named MAPS by its developers, ESR Technology, has been employed with considerable success out-with the pipeline industry.

Weatherford Pipeline and Speciality Services are presently working with ESR Technology in order to develop a pig-based inspection tool utilising this measurement technology. The initial aim is to provide a tool capable of diagnosing pipeline problems due to ground movement, spanning and other cause of bulk changes in stress. Refinement of the technique may make it possible to detect local increases in stress due to the presence of dents, metal loss defects etc.

Having as much knowledge as possible about assets and their pipelines and knowing how to analyse this information has become very important. In offshore pipelines intelligent pigging provides the clearest picture of the integrity of the pipeline. The information from these inspections can then be fed into the many assessment tools available in the market, for example:

• Semi-Quantitative Risk Assessments - Identifies the threats and their initiators affecting the integrity of the pipeline
• Corrosion Risk Assessments - Analyses the specific risk of internal and external corrosion to the pipeline
• FFP (Fitness for Purpose) - Conducts an assessment of the pipeline and its corrosion features according to various standards (B31.G, DNV etc,) to determine immediate repairs.
• Corrosion Growth Assessment - using the inputs from the above assessment tools this determines an accurate corrosion growth rate for calculating any future repairs and a re-inspection interval

The result of an intelligent pig inspection is an inspection report with a list of defects. To gain the full benefit from an inspection the pipeline operator must understand the inspection process, and what the list of defects means for the immediate and the future integrity of the pipeline.

Tool validation is a difficult task requiring detailed field measurements of features in a format that can be compared directly to the ILI data. This paper presents an overview of the validation process and describes the development and testing of a new device for measuring, documenting and assessing external corrosion on steel pipelines.

Feasibility and design of the new system were funded by the U.S. Department of Energy through the National Energy Technology Laboratory.

A great deal of work has been done on extending pipeline life by developing inspection technologies such as intelligent pigs, methods for recoating pipelines, techniques for internal painting, and hydrotesting regimes that will detect critical cracks. This wide range of options, the potential for problems such as a stuck pig, the costs associated, and the potential consequences of a failure, mean that a pipeline operator has to proceed very carefully when planning any inspection programme.

This paper will consider pipeline inspection based on the authors experiences from recent projects and recommend a simple strategy to ensure that a sensible, justifiable, plan is developed.

In a final stage the data of high-resolution ultrasonic inspection tools can be used to compare defects on a basis of wall thickness C-Scans. This will generate more precise conclusions about corrosion growth on single defects, which was not possible on the traditional statistical approach.

Major parameters to consider are wall thickness, length, requirements regarding resolution and accuracy and more and more the ability of the inspection tool to negotiate diameter variations.

This paper will provide an overview of available technologies and in-line inspection tools for the inspection of dual- and multi-diameter offshore pipelines. The paper will cover in-line inspection tools based on ultrasound-, magnetic flux leakage- and laser-based technologies covering geometry-, metal loss- as well as crack detection.

Pipeline pigging has a significant role to play in meeting these conditions, and pigs are met with in a number of guises during pre-commissioning operations. This paper is intended to provide an overview of the uses of pigs in these operations, and provide some basic information on train design and pig selection. Some examples are drawn from a range of types of construction and pre-commissioning projects in order to give a feel for the practicalities of the operations described.

BP Pipelines NA encouraged cooperation between all parties involved in the integrity process to adapt reporting requirements and work procedures to provide the best available information for integrity analysis and to ensure continued improvements. This cooperation is a key part of the integrity equation and essential to a successful program.

This paper presents an overview of the validation process undertaken on a 51 km (32-mile) section of 457 mm (18-inch) pipeline. This pipe section was inspected in 1999 and again in 2003 by the same inspection company. This provided an opportunity to evaluate improvements in inspection technology, assess repeatability of performance and develop an engineering based approach to review, analyze, and validate high-resolution metal loss MFL data. Field verification and data validation included the use of several NDE techniques to acquire field measurements to overlay and compare to the ILI inspection data.

Anomaly classification and distribution is examined and methods of selecting validation locations for future inspection developed. In addition to the primary goal outlined, the 2003 repair program provided an opportunity to evaluate the performance of the composite sleeve reinforcements applied in 1999, after 4 years of service.

In a final stage the data of high-resolution ultrasonic inspection tools can be used to compare defects on a basis of wall thickness C-Scans. This will generate more precise conclusions about corrosion growth on single defects, which was not possible on the traditional statistical approach.

Most internationally recognised repair codes such as ASME B31.4 and B31.8 accept the use of composites for this repair function.

Most oil and gas pipeline operators are familiar with composites and the health, safety, technical and commercial benefits they provide.

The purpose of this paper is to introduce new areas of repair applications where composites can be used and to provide case studies for these particular repair functions.

This paper will focus on some emerging issues relating to pipeline pigging operations in three specific areas; pigging pipelines under low flow conditions, pigging pipelines to control/mitigate MIC corrosion and new technology opportunities.

• They have a finite life - design versus achievable. Keep in good order and it will outlive the design (just as we need exercise and fitness)
• They need additional treatment as they get older - Biocide, corrosion inhibition, wax reducing agents (just as we need pills)
• Valves and control systems may not function to the standard required (just as our joints may need replacement)
• Closer operational control and monitoring is required to ensure no leaks or faults (just as we need more regular checks as we grow older)
• There is no substitute for actual inspection - intelligent pigging, subsea ROV camera etc (just as the doctor will diagnose us)
• How good is the documentation - it is essential that documentation for the pipeline is kept up-to-date including as built drawings, amendments etc (just as our medical history can assist the doctor)
• Changes in legislation affect:
  • How you manage the pipelines - PSRs, MAPDs Operator etc
  • Legislative authorities and who you communicate to - HSE Pipelines Inspectorate, DTI (just as pension changes may effect us)

The new intelligent plugging and pigging tools allow remote local pressure isolations at any water depth and at any position along a pipeline. The remote through-wall communication system reduces the number of vessels required during the flooding and commissioning of pipelines since pigs can communicate wirelessly their arrival and departure through the pipewall, through water and through air.

This paper presents the remote controlled pipeline isolation and pigging tools and describes the function and operation of each main sub-system. The paper presents historical applications with focus on subsea and midline pipeline isolations and interventions.

The method employs two tethered crawlers, one located close to the lay barge end and the other beyond the point where buckling is expected to occur. The tractors can "walk" in synch along the pipe. As both tractors are self-propelled, this proposed new method will remove the need to have a cable in tension. By fitting the second tractor with a camera and an array of sensors, video images and geometrical measurements of the newly laid pipe can be obtained in real time.

This paper focuses on selected areas of the TRACERCO Diagnostics™ technologies that are used for pipeline deposit measurements, specifically their location, amount, and profile within any length of pipeline.

This paper will show how the techniques are employed, the type of results that are achievable, and describe selected case studies.

It is evident that integration of data into a single, coherent data management system can provide significant benefits. However, the cost of implementing entirely new systems - with intensive data capture programs - is difficult to justify given the earlier investments. As a result dedicated risk management software using static and separately maintained data is often used as a quick, low cost alternative to meet regulatory compliance commitments.

Experience has shown that, with the right technology and an understanding of the specific needs of an organisation, a phased approach to integrated data management can be achieved at minimum initial cost by exploiting legacy data. This provides a low cost yet scalable solution that can grow with the changing needs of the business.

In addition to the benefits of legacy data integration, we will also look into the benefits of technologies for distributed data access to provide simple, process-focussed reporting tools.

SAAM® Smart Utility Pig technology has been deployed in these respects over the past 7 years in over 7,000km of pipeline. Over this time, the technology and analysis techniques have been developed, taking into account the experiences gained from previous surveys. This has led to recent improvements in the technology and increased confidence in the analysis results.

This paper describes the various capabilities of the smart utility pigging technology, giving examples from recent pipeline inspection surveys. These applications include: providing a vertical and horizontal pipeline profile, and using the results to monitor for movement or to assess pipeline strain; identifying mechanical damage, including bore restrictions, dents, illegal taps or offset couplings; providing an assessment of pipeline debris, estimating the remaining internal bore and determining the effectiveness of the pipeline cleaning program; and providing an assessment of internal corrosion.

The paper concludes with a brief description of special projects where the technology has been integrated with external sensors to provide additional information during a pig run, and a discussion of possible future improvements in the technology and data analysis.

The methodology involves assessing and weighting the effectiveness of nine key integrity activities:

• Integrity plan
• Risk Assessment
• Defect assessment
• Repair method
• Spill detection
• Corrosion prevention
• In-line inspection
• Third party damage prevention
• Failure history

Attention is also given to the cost of the Integrity Management activities. The benchmarking methodology identifies cost optimisation opportunities whilst maintaining acceptable safety levels.

The methodology has successfully been utilised to benchmark 140,000 km of pipelines worldwide and details are provided.

Knowing this, in-line inspection of the pipeline has to be applied, and before such inspection is executed, the line has to be clean. During the above mentioned Conference there was concluded "The cleaner, the better"!

So, the deviated topic for this presentation is "The cleaner, the better" and the central question during the whole presentation is "do pipelines need cleaning?" After the presentation, all of you could answer this question and I already know what it will be.

Total Cleaning	>>	the right conditions for in-line inspection
In-line Inspection	>>	correct readings and data collecting
Pipeline Integrity	>>	Interpretation of the data, resulting in acceptable or not
Safeguarded Production	>>	Operator/owner can anticipate on the future in time!

Every day there is a considerable amount of time and money spent on making mechanical pigging runs in pipelines, typically they are run for more than one reason:

• Cleaning the internal pipe wall surface;
• Removing free solids and debris;
• Gathering data about the integrity;
• Applying some sort of chemistry to the inside surface of the pipeline.

By adding special fluids to this process, the effectiveness of these runs can be enhanced:

• improving flow conditions;
• reducing differential pressures;
• removing more solids per run (more solids than 50 pig runs would achieve);
• reducing the risk of pigs getting stuck;
• optimizing chemical inhibition programs.

This paper will discuss the typical pipeline pig's design, this includes the different shapes of the components and materials used relate to the performance of the pig as it makes its journey through the line. Various limitations of pigs will be outlined due to their physical design versus the geometric shape of the surface to be cleaned. The limitations of commonly used solvents will be discussed along with what is required to make cleaning fluids more efficient.

This paper focuses on selected areas of the TRACERCO Diagnostics ™ technology as applied to Pipeline Inspection and Flow Assurance.

Customer problems were reduced to a set of functional requirements and through attention to detail monitored via an ISO 9001:2001 Quality Management system a solution to the particular problem is reached.

In the instance of the CMSS it was resolved early on in the design procedure that a new and revolutionary approach had to be adopted if the functional requirements were to be met whilst at the same time upholding the philosophy of FTL.

The majority of previously designed commissioning pigs adhered to well established design concepts in that all functions of the pig could be met with a relatively simple low cost design. The Åsgard multi diameter gas transporter line however was totally different.

The pipeline length would be 710 km at 42" diameter and the last 500 metres would reduce to 28" diameter. Drive disc and support disc wear would be a critical consideration.

By applying basic hydraulic cylinder design principals FTL decided that contrary to previous designs the support function of the pig should be completely separate from the sealing and drive function. Due to the expected high rate of wear that the sealing discs would have to withstand it was decided to take the hitherto unprecedented step for a commissioning pig to mount the whole unit on a self supporting and self centering suspension system.

By careful design and incorporating variable suspension geometry the potential to overload the wheel assemblies was avoided when passing from the larger to the smaller diameter pipeline sections. Furthermore, a slow controlled rotary motion would be imparted to the whole pig train to even out the wear on the discs.

This generic term can in some cases cause confusion, and the PPSA (Pipeline Pigging and Services Association) has endeavoured to be more correct and specific.

The paper presents current technology and describes the advantages and disadvantages of the various designs of dual diameter pig in the market. It also goes into detail of the function requirements of pigs and the validation process, which should be undertaken, prior to using a pig in a real life pipeline.

After a short summary of flaws and defects found in steel pipelines, the various physical principles utilised by intelligent pigs will be introduced and specific strength and weaknesses will be discussed.

Geometry, metal loss survey, crack detection and inertia tools will be introduced. Especially ultrasonic in-line inspection tools for wall thickness measurement and crack detection will be covered, regarding technology, vendors and defect specifications.