The impact of onshore oil and gas pipeline accident i.e., explosion varies depending on the pipeline location, transported product, proximity of residential areas and etc. Pipeline owner's reputation is threatened once an accident... more
The impact of onshore oil and gas pipeline accident i.e., explosion varies depending on the pipeline location, transported product, proximity of residential areas and etc. Pipeline owner's reputation is threatened once an accident takes place, which influences stakeholders' perceptions consequently. This study focuses on prioritizing the importance of the reputation loss factors according to the experts' judgments. Twenty two reputation loss factors were identified from 10 major pipeline explosion post-accident case studies. Nine experts were interviewed to rate importance level of the reputation loss factors using 10-point Likert scale rating method. The significance difference was obtained by the implementation of statistical analysis. Relative Importance Index (RII) was used to identify the importance level of the factor and Analytical Hierarchy Process (AHP) method for prioritization process with the aid of Super Decisions software. Results show that all reputation l...
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Pipeline integrity management programs address a wide range of threats to safe operations. Among these threats, external corrosion has been among the most dominant failure mechanism experienced by buried steel pipelines. External... more
Pipeline integrity management programs address a wide range of threats to safe operations. Among these threats, external corrosion has been among the most dominant failure mechanism experienced by buried steel pipelines. External corrosion can be detected through a variety of assessment methods, including inline inspection (ILI) and external corrosion direct assessment (ECDA). In the absence of data from inspection, the corrosion rate can be estimated based on the use of buried corrosion coupons, corrosion probes and corrosion rate modelling using data derived from soil analysis. The objective of the paper is to design a methodology of the external growth modelling of corrosion on buried gas pipelines under various exposures to soil conditions. The technique can be used to generate field data so as to model empirically the corrosion dynamic in soil or for verification of corrosion data from laboratory testing. The potential model based on the proposed technique is highly potential t...
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The oil and gas industry uses carbon steel pipelines as the basic element in transporting crude oil and gas. These pipelines are subjected to deterioration due to several factors, including third party damage, material and construction... more
The oil and gas industry uses carbon steel pipelines as the basic element in transporting crude oil and gas. These pipelines are subjected to deterioration due to several factors, including third party damage, material and construction defects, natural forces and corrosion. Deterioration of underground pipelines due to corrosion can lead to serious pipeline failures such as leakage and explosion. Hence, methods to repair such damage have been developed in order to extend the durability of pipelines. This paper reports on the current development of infill materials of epoxy grouts used for pipeline external repair. Assessment of the defects should be completed by pipeline operators to identify list of parameters including pipeline operating characteristic, geometries and materials of pipeline, and configuration and location of pipeline to make the best option of repair techniques. Therefore, selection of an appropriate rehabilitation system is crucial in preventing the future failure...
Risk assessment is the most significant factors in risk management. Earlier researches have shown that risk assessment is essential to achieve success in Engineering, Procurement and Construction projects(EPC). The occurrence of different... more
Risk assessment is the most significant factors in risk management. Earlier researches have shown that risk assessment is essential to achieve success in Engineering, Procurement and Construction projects(EPC). The occurrence of different risk can worsen the effects of each other such as the impact of political risks on economic risks. Although appointed methods such as Analytic Hierarchy Process (AHP), Fuzzy Synthetic, Interrelated Tree and Fuzzy AHP methods are commonly used in the industry sectors, yet these approaches seem powerless for evaluating the interactions and feedback between the aforementioned risks. As a result, an accurate assessment of the severity of risks cannot be determined. This study aims to assess the risks in EPC projects using Analytic Network Process (ANP) method. ANP approach is preferable in order to identify the problems of interdependence and feedback between various risk ranking alternatives. The method utilizes data that are collected through literat...
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Sulphate-reducing bacteria (SRB) as the main source of Microbiologically Influenced Corrosion (MIC) mechanism has a dominant influence upon localized corrosion problems especially for internal piping. In this paper, corrosion behavior of... more
Sulphate-reducing bacteria (SRB) as the main source of Microbiologically Influenced Corrosion (MIC) mechanism has a dominant influence upon localized corrosion problems especially for internal piping. In this paper, corrosion behavior of high-strength carbon steel (API 5L X-70) under anaerobic conditions in the presence of SRB's bacteria was studied in batch reactor. The coupons were exposed to the SRB culture for 1, 3, 6, 10, 20 and 30 days at 22 0 C and 37 0 C along with a control set. Corrosion rate in SRB medium at 37 0 C showed a higher dynamic value compared to medium inoculated at 22 o C. The corrosion rate of the carbon steel also showed no correlation with the planktonic or sessile SRB cell numbers.
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Risk allocation is a key to managing risks associated with the public private partnership projects. Optimal risk allocation between the parties involved, namely public and private, is the essence of successful PPP... more
Risk allocation is a key to managing risks associated with the public private partnership projects. Optimal risk allocation between the parties involved, namely public and private, is the essence of successful PPP project implementation. This study intends to identify and prioritize significant risk allocation criteria and barriers preventing the optimal allocation of risk to PPP projects in Malaysia. Due to interaction among criteria and barriers, this research has adopted analytic network process in order to decompose decision model into meaningful network and weight decision elements. Data has been collected through literature review, questionnaire and interview with PPP project experts. This study reveals that "Bear the risk at lowest price", "Control the chance of risk" and "Risk attitude" are three major optimal risk allocation criteria. "Different sets of information about project risk", "Lack of efficient risk allocation mechanisms" and "Lack of understanding the benefits of optimal allocation" are of three major optimal risk allocation barriers identified throughout the study. The outcome can be used to improve the implementation of PPP project in Malaysia by more rationally allocating risks between parties involved.
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This study defines the interrelationship between turbidities and cell number counting efficiency for the growth of one of the microbiologically influenced corrosion (MIC) species in a medium. The metabolism activities during bacteria... more
This study defines the interrelationship between turbidities and cell number counting efficiency for the growth of one of the microbiologically influenced corrosion (MIC) species in a medium. The metabolism activities during bacteria growth can accelerate the corrosion process and shorten the reliability of pipelines. Thus, the investigation of MIC species’ development and metabolic activities is significant. An experiment was performed on sulfate-reducing bacteria (SRB) that practiced the medium as the substance to grow. Desulfovibrio vulgaris, a strain of SRB, was cultured in a postgate C medium to measure the bacteria survival using two different measurement methods. The medium was modified to pH 7.5 at 37°C and placed in anaerobic vials. During 24 hours of incubation, samples were retrieved, and the value of turbidity and cell numbers was measured. Based on the SRB growth graph pattern, the amount of bacteria cell numbers was increased parallel to the value of the medium’s turbidity in respect to time. Both values (turbidity and bacteria cell numbers) dramatically increased from hour1 to hour24. The results supported that the turbidity value was positively correlated with bacteria cell numbers.
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In the past two decades, public private partnership has been one of the prevailing ways for the development of infrastructures in Malaysia. However, it involves many risks and uncertainties due to a large amount of investment and long... more
In the past two decades, public private partnership has been one of the
prevailing ways for the development of infrastructures in Malaysia. However, it
involves many risks and uncertainties due to a large amount of investment and long
concession period. It is very important to recognize and find out the ways to cope
with the critical risks that are related to the investments made in PPP projects for the
foreign investors. The aim of this article is risk ranking associated with the PPP
projects using risk matrix. First, the paper reviews the current literature, consultation
and a written survey distributed to the panel of experts to identify common risks in
PPP projects
. The risks identified from the literature were classified according to the
type of risk. From the results, it was found that the critical risks associated with the
PPP projects include the third party tort liability, interest rate volatility, construction
cost overrun and the change in law. This research study is supposed to provide
awareness and highlight the management of the risks associated with the PPP risks in
Malaysia.
prevailing ways for the development of infrastructures in Malaysia. However, it
involves many risks and uncertainties due to a large amount of investment and long
concession period. It is very important to recognize and find out the ways to cope
with the critical risks that are related to the investments made in PPP projects for the
foreign investors. The aim of this article is risk ranking associated with the PPP
projects using risk matrix. First, the paper reviews the current literature, consultation
and a written survey distributed to the panel of experts to identify common risks in
PPP projects
. The risks identified from the literature were classified according to the
type of risk. From the results, it was found that the critical risks associated with the
PPP projects include the third party tort liability, interest rate volatility, construction
cost overrun and the change in law. This research study is supposed to provide
awareness and highlight the management of the risks associated with the PPP risks in
Malaysia.
Research Interests:
Research Interests:
Risk allocation is the most significant factor in risk management. Earlier research has shown that risk allocation is essential to achieve success in construction projects. Risk allocation may fail to be achieved due to lack of a... more
Risk allocation is the most significant factor in risk management. Earlier research has
shown that risk allocation is essential to achieve success in construction projects. Risk allocation
may fail to be achieved due to lack of a mechanism for joint risk management. Successful optimal
risk allocation requires one to identify and evaluate the risk allocation criteria, which interact and
overlap with each other and can lead to significant variation in the decision outcome in risk
allocation. This study aims to allocate the risks in EPC projects using the analytic network process
(ANP) method. The ANP approach is preferable in identifying the problems of interdependence and
feedback among various criteria factors. The method utilizes data that are collected through a
literature review, interviews, and a questionnaire distributed to EPC project experts. The results
have shown that 12 risks are allocated to the developer, 9 risks are shared between developer and
contractor, and 12 risks are allocated to the contractor. In conclusion, ANP is found to be suitable in
analyzing the feedback and interdependencies among risk allocation criteria.
shown that risk allocation is essential to achieve success in construction projects. Risk allocation
may fail to be achieved due to lack of a mechanism for joint risk management. Successful optimal
risk allocation requires one to identify and evaluate the risk allocation criteria, which interact and
overlap with each other and can lead to significant variation in the decision outcome in risk
allocation. This study aims to allocate the risks in EPC projects using the analytic network process
(ANP) method. The ANP approach is preferable in identifying the problems of interdependence and
feedback among various criteria factors. The method utilizes data that are collected through a
literature review, interviews, and a questionnaire distributed to EPC project experts. The results
have shown that 12 risks are allocated to the developer, 9 risks are shared between developer and
contractor, and 12 risks are allocated to the contractor. In conclusion, ANP is found to be suitable in
analyzing the feedback and interdependencies among risk allocation criteria.
Research Interests:
In the past two decades, public private partnership (PPP) has been one of the prevailing ways for the development of infrastructure in Malaysia. However, it involves many risks and uncertainties due to large investments and a long... more
In the past two decades, public private partnership (PPP) has been one of the prevailing
ways for the development of infrastructure in Malaysia. However, it involves many risks and
uncertainties due to large investments and a long concession period. It is very important to
recognize and find out ways to cope with the critical risks that are related to the investments made
in PPP projects by foreign investors. The aim of this article is to risk ranking associated with PPP
projects using a risk matrix. The papers carries out literature review, consultation and questionnaire
survey (among a panel of experts) to identify common risks in PPP projects. The risks identified
from the literature were classified according to the type of risk. Finally, the results show that third
party tort liability, interest rate volatility, construction cost overruns, and changes in law are critical
risks.
ways for the development of infrastructure in Malaysia. However, it involves many risks and
uncertainties due to large investments and a long concession period. It is very important to
recognize and find out ways to cope with the critical risks that are related to the investments made
in PPP projects by foreign investors. The aim of this article is to risk ranking associated with PPP
projects using a risk matrix. The papers carries out literature review, consultation and questionnaire
survey (among a panel of experts) to identify common risks in PPP projects. The risks identified
from the literature were classified according to the type of risk. Finally, the results show that third
party tort liability, interest rate volatility, construction cost overruns, and changes in law are critical
risks.
Research Interests:
Research Interests:
Research Interests:
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Abstract: A semi-probabilistic methodology for predicting the remaining strength of submarine pipelines subjected to internal corrosion based on Recommended Practice RP-F101 by Det Norske Veritas (DNV) is described in this paper. It is... more
Abstract: A semi-probabilistic methodology for predicting the remaining strength of submarine pipelines subjected to internal corrosion based on Recommended Practice RP-F101 by Det Norske Veritas (DNV) is described in this paper. It is used to estimate the ...
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Pipelines those have been buried under seabed sediment are at risk of corrosion due to the corrosiveness of this particular environment. Hereby, corrosion experimental study has been conducted to highlight the importance of near shore... more
Pipelines those have been buried under seabed
sediment are at risk of corrosion due to the corrosiveness
of this particular environment. Hereby, corrosion
experimental study has been conducted to highlight the
importance of near shore sediment as an aggressive
environment towards steel structures. Coupons made
from API X70 steel of actual pipe have been considered
to calculate the corrosion rate by means of weight lost
determination at both near shore and offshore areas. The
results show that the corrosion rates of coupons buried at
near shore area were higher than corrosion rates at
offshore. Convincingly, near shore environment has
shown a significant influence on corrosion rates of steel
pipelines.
sediment are at risk of corrosion due to the corrosiveness
of this particular environment. Hereby, corrosion
experimental study has been conducted to highlight the
importance of near shore sediment as an aggressive
environment towards steel structures. Coupons made
from API X70 steel of actual pipe have been considered
to calculate the corrosion rate by means of weight lost
determination at both near shore and offshore areas. The
results show that the corrosion rates of coupons buried at
near shore area were higher than corrosion rates at
offshore. Convincingly, near shore environment has
shown a significant influence on corrosion rates of steel
pipelines.
Research Interests:
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The paper presents a probabilistic-based methodology for the assessment of a pipeline containing internal corrosion defects. Two different models have been used to predict the future CO2 corrosion rates namely a linear growth and the... more
The paper presents a probabilistic-based methodology for the assessment of a pipeline containing internal corrosion defects. Two different models have been used to predict the future
CO2 corrosion rates namely a linear growth and the deWaard-Milliams models. A probabilistic approach is used to analyse the behaviour of corrosion data obtained from in-line intelligent (ILI)
pigging inspections. The outcomes are parameters represented by their corresponding statistical distribution. Due to the availability of these statistical parameters, a Monte Carlo simulation is used to calculate the probability of failure of the pipeline due to bursting failure. The existence of corrosion may reduce the maximum capacity of the pipe, as such causing leakage and bursting when the operational pressure supersedes its threshold. From the analysis of the result, failure probability based on theoretical linear growth model exhibit slightly longer lifetime of the pipeline with three years interval compared to deWaard-Milliams model. This is due to higher mean value of corrosion growth rate estimated using the empirical deWaard-Milliams model. Both results are very useful in prolonging the lifetime of pipelines by having knowledge of the
past to schedule the future maintenance work.
CO2 corrosion rates namely a linear growth and the deWaard-Milliams models. A probabilistic approach is used to analyse the behaviour of corrosion data obtained from in-line intelligent (ILI)
pigging inspections. The outcomes are parameters represented by their corresponding statistical distribution. Due to the availability of these statistical parameters, a Monte Carlo simulation is used to calculate the probability of failure of the pipeline due to bursting failure. The existence of corrosion may reduce the maximum capacity of the pipe, as such causing leakage and bursting when the operational pressure supersedes its threshold. From the analysis of the result, failure probability based on theoretical linear growth model exhibit slightly longer lifetime of the pipeline with three years interval compared to deWaard-Milliams model. This is due to higher mean value of corrosion growth rate estimated using the empirical deWaard-Milliams model. Both results are very useful in prolonging the lifetime of pipelines by having knowledge of the
past to schedule the future maintenance work.