Search results

There has been a sustained interest over the past couple of decades in developing sophisticated leak detection techniques (LDTs) that are economical and reliable. Majority of current commercial LDTs are acoustics based and they are not equally suitable to all pipe materials and sizes. There is also limited knowledge on the comparative merits of such acoustics-based leak detection techniques (ALDTs). The purpose of this paper is to review six commercial ALDTs based on four decisive criteria and subsequently develop guidance for the optimal selection of an ALDT.

Numerous publications and field demonstration reports are reviewed for evaluating the performance of various ALDTs in this study to inform their optimal selection using an integrated multi-criteria decision analysis (MCDA) framework. The findings are validated using interviews of water utility experts.

The study approach and the findings will have a broad impact on the water utility industry by identifying a suite of suitable ALDTs for a range of typical application scenarios. The evaluated ALDTs include listening devices, noise loggers, leak-noise correlators, free-swimming acoustic, tethered acoustic, and acoustic emissions. The evaluation criteria include cost, reliability, access requirements, and the ability to quantify leakage severity. The guidance presented in this paper will support efficient decision making in water utility management to minimize pipeline leakage.

This study attempts to address the problem of severe dearth of performance data for pipeline inspection techniques. Performance data reported in the published literature on various ALDTs are appropriately aggregated and compared using a MCDA, while the uncertainty in performance data is addressed using the Monte Carlo simulation approach.

Quantitatively detecting surface defects in a circular annulus with high levels of accuracy and efficiency has been paid more attention by researchers. The purpose of this study is to investigate the theoretical dispersion equations for circumferential guided waves and then develop an efficient technique for accurate reconstruction of defects in pipes.

The methodology applied to determine defects in pipelines includes four steps. First, the theoretical work is carried out by developing the appropriate dispersion equations for circumferential guided waves in a pipe. In this phase, formulations of strain-displacement relations are derived in a general equidistant surface coordinate. Following that, a semi-analytical finite element method (SAFEM) is applied to solve the dispersion equations. Then, the scattered fields in a circular annulus are calculated using the developed hybrid finite element method and simulation results are in accord with the law of conservation of energy. Finally, the quantitative detection of Fourier transform (QDFT) approach is further enhanced to efficiently reconstruct the defects in the circular annuli, which have been widely used for engineering applications.

Results obtained from four numerical examples of flaw detection problems demonstrate the correctness of the developed QDFT approach in terms of accuracy and efficiency. Reconstruction of circumferential surface defects using the extended QDFT method can be performed without involving the analytical formulations. Therefore, the streamlined process of inspecting surface defects is well established and this leads to the reduced time in practical engineering tests.

In this paper, the general dispersion equations for circumferential ultrasonic guided waves have been derived using an equidistant surface coordinate and solved by the SAFEM technique to discover the relationship between wavenumber of a wave and its frequency. To reconstruct defects with high levels of accuracy and efficiency, the QDFT approach has been further enhanced to inspect defects in the annular structure.

The purpose of this paper is to develop an auditing framework which would assist the organizations that experience difficulties with the current ISO 9001 quality audits to achieve their planned objectives with regard to their auditing of conformance, performance, risk management (RM) and improvement collectively.

A literature review was conducted to develop a conceptual audit framework (CAF). Subsequently, a preliminary audit framework (PAF) was developed. It includes the questions that are based on the CAF and connected with the complaints of the concerned organization. This PAF was thoroughly tested and validated by performing 11 internal audits, 2 management reviews (MR) and 3 workshops.

Applying this PAF indicated that in order to help organizations to audit their performance, RM and improvement collectively, they need to: change their audit approach from ISO elements to ISO principles, integrate the tools that are related to ISO 9001 Principles within the audit’s phases, perform pre-audits in the form of self-auditing, induce auditors to learn all tools to determine the ideal tools for particular situation, audit each department in combination with its internal customer, involve their auditors in problem solving, perform MR prior to closing the audit and analyze the results of audits with their causes by using one of the appropriate qualitative methods, such as analysis by themes. Finally, an auditing framework was developed to meet these needs. It includes the PAF’s questions that led to the discovery of chronic and systematic audit findings. It enhances any ISO 9001 Quality Auditing Questionnaires Checklist.

This study enhances the role of auditors to include risk identification, problem solving and data analysis by development of an auditing framework that is based on ISO 9001 Principles rather than clauses.

The existing method of pipeline health monitoring, which requires an entire pipeline to be inspected periodically, is both time‐wasting and expensive. A risk‐based model that reduces the amount of time spent on inspection has been presented. This model not only reduces the cost of maintaining petroleum pipelines, but also suggests efficient design and operation philosophy, construction methodology and logical insurance plans. The risk‐based model uses Analytic Hierarchy Process (AHP), a multiple attribute decision‐making technique, to identify the factors that influence failure on specific segments and analyzes their effects by determining probability of risk factors. The severity of failure is determined through consequence analysis. From this, the effect of a failure caused by each risk factor can be established in terms of cost, and the cumulative effect of failure is determined through probability analysis. The technique does not totally eliminate subjectivity, but it is an improvement over the existing inspection method.

The purpose of this paper is to develop a novel autonomous in‐pipe robot to perform the preventive point reparation for long‐distance offshore oil pipelines.

The autonomous in‐pipe robot performs online ultrasonic inspection for pipe wall thickness, and the original inspection data are stored in large capacity hard disk. Through the offline data analysis by the data analysts and the software tool, the pipeline health status is known. If server defects lie there, the in‐pipe robot is introduced into the pipeline once more to indicate the defect's location to the maintenance ship.

The laboratory tests and the field tests prove the feasibility and validity of the developed autonomous in‐pipe robot. Furthermore, the application of intelligent control techniques ensures the mission completion by the autonomous in‐pipe robot, which worked in the awful pipeline environment.

The developed autonomous in‐pipe robot helps eliminate lost production costs and pipeline downtime caused by leakages and guarantees the safe run of offshore oil pipelines.

For the application of the autonomous in‐pipe robot, there are no special requirements for maintained pipelines themselves, so it is applicable to the point reparation for most long‐distance welded offshore pipelines.

Offshore oil and gas pipelines are vulnerable to environment as any leak and burst in pipelines cause oil/gas spill resulting in huge negative impacts on marine lives. Breakdown maintenance of these pipelines is also cost‐intensive and time‐consuming resulting in huge tangible and intangible loss to the pipeline operators. Pipelines health monitoring and integrity analysis have been researched a lot for successful pipeline operations and risk‐based maintenance model is one of the outcomes of those researches. This study develops a risk‐based maintenance model using a combined multiple‐criteria decision‐making and weight method for offshore oil and gas pipelines in Thailand with the active participation of experienced executives. The model's effectiveness has been demonstrated through real life application on oil and gas pipelines in the Gulf of Thailand. Practical implications. Risk‐based inspection and maintenance methodology is particularly important for oil pipelines system, as any failure in the system will not only affect productivity negatively but also has tremendous negative environmental impact. The proposed model helps the pipelines operators to analyze the health of pipelines dynamically, to select specific inspection and maintenance method for specific section in line with its probability and severity of failure.

This paper aims to report on the findings from a research project, incorporated by Iran’s Ministry of Petroleum, investigating the integration of inspection management with analysis of document information.

A combination of group and individual interviews were undertaken with qualitative methods of analysis to develop an integrated process model. The model developed uses integrity management factors, which allows flexibility and the early integration of inspection management systems at a strategic level, although detailed planning is still required through the use of integrated management tools. The model combines information on responsibilities, tasks and policies, of personnel in the inspection management of the piping system with the oil and gas industry.

The six inspection activities recognized for the main practical model are, namely, identify pipeline situation; inspect and measure defects; inspection assessment; design inspection; implement inspection activities and measure and report inspection.

This research presented not only a process but also the framework and techniques to manage and improve management effectiveness and inspection efficiency in pipelines of the oil and gas industry. This study will be useful to researchers maintenance professionals and others concerned with inspection and maintenance management of facilities and equipment in the oil and gas industry.

The purpose of this paper is to develop an easy and robust tool to develop a decision support system (DSS) for the inspection staff of oil pipelines. The aim is to predict “the class” of each spillage, with respect to some relevant variables such as, mechanical failure or system malfunction. The management will then be able to define which pipelines to monitor and to choose the most suitable monitoring policies, based on the decision tree analysis outcome.

A non‐parametric technique based on rule induction is proposed for the identification of the expected spill cause category of cross‐country oil pipelines. In particular, the classification and regression trees approach is used to automatically generate inspection or maintenance decision rules. The analysis that is described is based on an extended database concerning information about spill cause category in cross‐country oil pipelines in Western Europe.

The proposed technique represents an interesting added value tool for the management. The proposed methodology extrapolates rules for determining the expected spill cause category of cross‐country pipelines, depending on the boundary conditions.

The methodology here presented will assist maintenance managers of oil pipeline to better plan maintenance activity. In particular, the procedure makes it possible to determine which parts of a pipeline have to be submitted to a monitoring action or particular protection, with the aim of improving the efficiency and reducing the risk of spillages.

Effective planning, coordination, and scheduling of the maintenance function can be, and for many years was, accomplished without computer support. The proposed procedure may be included in an information systems tool (sound Computerized Maintenance Information Management System (CMMIS)), for more efficient and effective maintenance/inspection scheduling activities.

The purpose of this study is to develop a robot for non-destructive testing of the pipelines to improve its reliability and reduce the loss of products due to cracks, corrosions, etc.

In this study, an inline inspection robot was developed for crack and corrosion detection in the pipeline. The developed robot consists of ultrasonic sensors to avoid obstacles, a visual aid with high resolution to view real time images and colour sensors for corrosion detection. The Autodesk inventor software was used for the drafting and solid modelling of the robot. A dummy pipe of 500 mm diameter and 2,000 mm length with induced cracks and corrosion was fabricated to test the robot. The colour sensors placed at each side of the robot were used to detect corrosion in the dummy pipe whilst the image processing was done to analyse the crack, as well as the type and depth of corrosion present in the dummy pipe.

The results obtained show the ability of the developed robot to detect cracks and determine the crack growth in the pipeline in addition to its ability to determine corrosion.

Hence, the study provides a diagnostic tool for detecting pipeline defects and analysing the extent of defects to determine the fatigue rate and the useful life of the pipeline.

The novelties of this study is based on the fact that it was designed to avoid obstacles and check for cracks, leakage and corrosion in pipelines autonomously. It has visual aid that makes it possible to see the interior of the pipe. This makes it easier to identify the defect and the location of the defects before a catastrophic failure. The device is also equipped with sensors, which can detect defects and send the signal to a control system, as well as a Bluetooth device so the operator can have real time information about the state and integrity of the pipelines. The system is also integrated with a Bluetooth device, which permits its compatibility with Android and other mobile applications. Thus, the enabled user can send a command to query the state of the pipeline at any location with the feedback received in the form of short message service. Hence, this study offers contribution in the development of an independent (self-governing) system with the capability to autonomously detect defects in pipe walls and effectively communicate feedback to the authorised users. The prototype model for the evaluation of pipeline integrity will bring about a more proactive way to detect pipeline defects so that effort can be geared towards its restoration before it becomes a major problem, which will subsequently affect productivity and incur losses.

The purpose of this paper is to describe the reviews of past research work on various in-pipe robotic systems and their operations. This investigation has been focussed on the implemented methodologies for performing in-pipe cleaning and inspection tasks.

This work has been concentrated on review of various sensors used in robots to perform in-pipes inspection operation for determining flaws/cracks, corrosion-affected areas, blocks and coated paint thickness. Various actuators like DC motors, servo motors, pneumatic operated and hydraulic operated are discussed in this review analysis to control the motion of various mechanical components of the robot.

In the current analysis, categorisation of various pipe cleaning robots according to their mechanical structure has been addressed. A lot of information has been gathered regarding the control of in-pipe robots for performing inspection and cleaning tasks.

In this paper, various in-pipe cleaning and inspection techniques have been studied. Necessary information provided regarding different types of in-pipe robots like PIG, wall-pressed, walking, wheel and inchworm. This investigation provides a through literature on various types of sensors like ultrasonic, magnetic, touch, light amplification by stimulated emission of radiation, X-ray, etc., that have been used for inspection and detection of flaws in the pipe.