Application of Probabilistic Methods for Predicting the Remaining Life of Offshore Pipelines

2014 ◽  
Author(s):  
Alireda Aljaroudi ◽  
Premkumar Thodi ◽  
Ayhan Akinturk ◽  
Faisal Khan ◽  
Mike Paulin
Keyword(s):  
Oil And Gas ◽  
Probabilistic Methods ◽  
Assessment Process ◽  
Pipeline System ◽  
Remaining Life ◽  
Operating Characteristics ◽  
Offshore Pipelines ◽  
Design Life ◽  
Course Of Action ◽  
Oil Flow

When offshore pipelines are approaching the end of their design life or have gone beyond their design life, their condition could possibly threaten oil flow continuity (through leak or rupture) as well as become a potential safety or environmental hazard. Some of the pipelines may show signs of deterioration and ageing due to corrosion, cracking or other damage mechanisms. Any assets, such as the pipeline, may be desired to continue transporting hydrocarbons beyond its design life due to increased oil and gas demand, due to unforeseen increased oil and gas reserves, or due to upgrade where additional assets are tied-into the existing pipeline system. Other situations may force operators to maintain the pipeline’s design life in spite of premature ageing of the pipe wall caused by the increased corrosion growth or other anomalies. Hence, there may be a need to assess the remaining life of pipeline in order to determine if it is capable of coping with current and future operational demand. The first task in the assessment process is to identify degradation mechanisms and their rate of growth, then estimate uncertainties in the collected data concerning pipeline flaw geometry, pipeline mechanical properties and operating characteristics. Based on the collected data and the assessment, the probability and consequence of failure can be determined. The remaining life of a pipeline is the time it takes the pipeline to fail or exceed the target failure probability. This paper presents a methodology for assessing the condition of ageing pipelines and determining the remaining life that supports extended operation without compromising safety and reliability. Applying this methodology would facilitate a well-informed decision that enables decision makers to determine the best strategy or adequate course of action for assessing and maintaining the integrity of ageing pipelines.

Probabilistic Methods for Predicting the Remaining Life of Offshore Pipelines

2017 ◽  
Vol 139 (4) ◽  
Author(s):  
Alireda Aljaroudi ◽  
Premkumar Thodi ◽  
Ayhan Akinturk ◽  
Faisal Khan ◽  
Mike Paulin
Keyword(s):  
Environmental Hazard ◽  
Decision Makers ◽  
Probabilistic Methods ◽  
Remaining Life ◽  
Offshore Pipelines ◽  
Design Life ◽  
Potential Safety ◽  
Oil Flow ◽  
Safety And Reliability ◽  
Extended Operation

When offshore pipelines approach the end of their design life, their condition could threaten oil flow continuity as well as become a potential safety or environmental hazard. Hence, there is a need to assess the remaining life of pipelines to ensure that they can cope with current and future operational demand and integrity challenges. This paper presents a methodology for assessing the condition of aging pipelines and determining the remaining life that can support extended operation without compromising safety and reliability. Applying this methodology would facilitate a well-informed decision that enables decision makers to determine the best strategy for maintaining the integrity of aging pipelines.

Late life management of onshore and offshore pipelines

2015 ◽  
Vol 55 (2) ◽  
pp. 414
Author(s):  
Brian Humphreys ◽  
Wacek Lipski
Keyword(s):  
Oil And Gas ◽  
Life Review ◽  
Remaining Life ◽  
Offshore Pipelines ◽  
Field Development ◽  
Design Life ◽  
Inspection And Maintenance ◽  
1960S And 1970S ◽  
The 1960S ◽  
Opening Up

The Australian oil and gas boom of the 1960s and 1970s lead to production commencing in the Gippsland, Surat, Cooper and Carnarvon basins and so many pipeline assets around Australia are approaching operating lives of 40-50 years and the end of their design lives. With unconventional field development and the Australian gas markets opening up to international customers through LNG, there will be an increasing requirement to extend the life of pipelines while maintaining safety and integrity. The management of pipeline assets late in their design life is a challenge for operators both onshore and offshore, with pipelines requiring higher levels of inspection and maintenance, while revenues can be fixed or regulated for downstream assets or potentially declining for upstream assets. To operate pipelines beyond their specified design life, there are requirements that must be fulfilled—for offshore, a design re-qualification in accordance with DNV-OS-F101 and for onshore, a remaining life review in accordance with AS2885.3. In addition, for onshore pipelines, AS2885.3 requires the remaining life review process to be undertaken every 10 years, rather than just at the end of the design life. This extended abstract discusses the requirements of the DNV-OS-F101 and AS2885.3 and the approaches required to meet these requirements. It also discusses key lessons that have been learned and makes recommendations to pipeline operators preparing for end-of-design-life reviews and executing them as cost effectively as possible.

Pragmatic Approach to Estimate Corrosion Rates for Pipelines Subject to Complex Corrosion

2014 ◽  
Author(s):  
Markus R. Dann ◽  
Luc Huyse
Keyword(s):  
Measurement Errors ◽  
Oil And Gas ◽  
High Density ◽  
Probabilistic Methods ◽  
Life Assessment ◽  
Remaining Life ◽  
Pragmatic Approach ◽  
Internal Corrosion ◽  
Corrosion Rates ◽  
Remaining Life Assessment

Corrosion is a common degradation process for most oil and gas pipelines in operation that can lead to leak and rupture failures. To avoid failures due to corrosion, integrity management plans for pipelines require fitness-for-service (FFS) assessments and remaining life analysis of the corrosion features that are detected by in-line inspections (ILIs). The objective of the present paper is to support the deterministic integrity and remaining life assessment of pipelines by introducing a pragmatic approach for the determination of corrosion rates from two inspections. The proposed approach is primarily tailored towards upstream and subsea pipelines that are subject to very high density internal corrosion rather than transmission pipelines with low to moderate densities of external features. ILI data may be subject to significant measurement errors and feature matching for two ILIs can become highly unreliable if high-density corrosion is present. To address these uncertainties, the backbone of the proposed approach is to focus on corrosion clusters rather than individual corrosion pits and a filtering process is utilized to identify true corrosion growth. The introduced approach is supported by theoretical knowledge and practical experience. The approach can be easily executed in spreadsheet software tools without the application of advanced statistical and probabilistic methods for the deterministic remaining life assessment in practice.

Life Extension of Ageing Offshore Structures: A Framework for Remaining Life Estimation

2017 ◽  
Author(s):  
Ashish Aeran ◽  
Sudath C. Siriwardane ◽  
Ove Mikkelsen ◽  
Ivar Langen
Keyword(s):  
Fatigue Damage ◽  
Oil And Gas ◽  
Oil And Gas Industry ◽  
Offshore Structures ◽  
Assessment Process ◽  
Localized Corrosion ◽  
Life Extension ◽  
Remaining Life ◽  
Structural Degradation ◽  
Life Estimation

The remaining life estimation of ageing structures has been identified as a growing challenge in the oil and gas industry. Although the available guidelines provide a general fatigue assessment process, it is necessary to have more detailed guidelines by adding relevant theories and models which can capture the time-dependent structural degradation more precisely. To address this, a new framework is proposed in this paper. The proposed framework provides recommendations on various issues such as simulation of structural degradation, loading history, effect of localized corrosion, selection of a suitable fatigue strength curve and fatigue damage theories. Recently developed precise fatigue damage theory is also included in the proposed framework.

Remaining Life Assessment and Life Extension of Offshore Pipelines

2018 ◽  
Author(s):  
Jens P. Tronskar
Keyword(s):  
Life Assessment ◽  
Life Extension ◽  
Remaining Life ◽  
Original Design ◽  
Offshore Pipelines ◽  
Field Development ◽  
Design Life ◽  
The Future ◽  
Cost Efficient ◽  
Remaining Life Assessment

Cost efficient offshore field development often involves tiebacks to existing field infrastructure. Efficient field development requires life extension of existing production facilities and pipelines to accommodate the new field resources over their life expectation. For fields near the tail end of their production the pipelines may be close to the end of their design life, and it must be shown that they have potential for extended life beyond the original design life until the end of the period of operation of the new field. Offshore pipelines are designed and constructed to recognized standards, such as the widely applied DNV OS-F101 2013 Submarine Pipelines Systems and earlier versions. The latest edition of the code was recently issued as a standard with some major updates and a modified code number i.e. DNVGL ST-F101 [1]. As pipelines age, they will inevitably be exposed to various types of degradation and an Operator must be able to both assess the significance of this damage and the pipeline remaining life to ensure that the pipelines do not fail as they age before the end of their design lives. Currently, many pipelines are operated far beyond the original design life and as mentioned above for cost efficient field development the pipeline operator often needs to demonstrate that the pipeline’s useful life can be extended another 10 or in some cases up to 30 years. For some pipelines, new operating conditions will be introduced by tie-in of new fields and this will impact the future rate of degradation. Hence, it cannot be assumed that the future degradation will be similar or less severe than experienced since commissioning of the pipeline. Extension of the life of the pipeline can be demonstrated by adopting methods of analysis that show the line is safe for an extended life under the future expected operating condition. This paper describes the risk based approach applied for pipeline remaining life and life extension analyses based on DNV GL codes and other relevant recommended practices. For illustration of the methodology a typical case of remaining life assessment of and life extension of a gas export pipeline is presented in the Case Study.

Probabilistic Integrity Assessment of Pipelines and Pressure Vessels With Localized Corrosion

2005 ◽  
Author(s):  
Jens P. Tronskar ◽  
Zhang Li ◽  
John D. Edwards
Keyword(s):  
Corrosion Rate ◽  
Oil And Gas ◽  
Corrosion Damage ◽  
Extreme Value ◽  
Pressure Vessels ◽  
Localized Corrosion ◽  
Probabilistic Assessment ◽  
Remaining Life ◽  
Offshore Pipelines ◽  
The Future

The acceptability of localized corrosion for pipelines in service is discussed and the methodology for probabilistic assessment of corrosion damage using the 2004 revision of Det Norske Veritas document DNV-RP-F101 is presented with regard to predicting the remaining life of onshore, offshore pipelines and also pressure vessels for the oil and gas industry. Capacity assessment of corrosion defects in pipelines and pressure vessels is a challenge for the industry, and has resulted in several methods and codes in the recent years. The methods include ASME B31G for pipelines and other standards and recommended practices that can be applied for pipelines as well as pressure vessels such as BS7910 Annex G and API 579. In 1999 DNV issued a recommended practice for the assessment of corroded pipelines, DNV-RP-F101, which was developed in co-operation with the pipeline industry. A revision of this document was issued in October 2004. The latest revision provides guidelines for probabilistic assessment of the pipeline reliability and remaining life. Pipeline corrosion is often of localized nature and depends on many factors such as fluid composition and partial pressures, temperature, pH, flow rate and efficiency of corrosion inhibition. These factors may not be easy to quantify with great certainty and a probabilistic approach is particularly justified. An approach is presented in this paper where the actual measured corrosion damage is fitted to an extreme value distribution. The future corrosion rate distribution for internal CO2 corrosion is predicted using the latest de Waard and Milliams model and an inhibitor distribution, to predict the corrosion of each pipeline segment. An Gumbel type extreme value approach is applied to estimate the present condition and the local corrosion flaw distribution that may cause a leak of the pipeline in the future. The future corrosion is estimated using the anticipated future operating conditions of the pipeline to predict the corrosion rate distribution expressed in terms of a Weibull distribution. The paper highlights three cases as examples where the approach has been applied for assessing the probability of failure and reliability during service of two offshore pipelines carrying oil and gas with wet CO2, and one stainless steel pressure vessel in a process plant occasionally exposed to trace amounts seawater originating from leaking heat exchangers.

Gas pipeline leakage detection in the presence of parameter uncertainty using robust extended Kalman filter

2021 ◽  
pp. 014233122198911
Author(s):  
Mohadese Jahanian ◽  
Amin Ramezani ◽  
Ali Moarefianpour ◽  
Mahdi Aliari Shouredeli
Keyword(s):  
Kalman Filter ◽  
Extended Kalman Filter ◽  
Parameter Uncertainty ◽  
Oil And Gas ◽  
Estimation Error ◽  
Real Data ◽  
Gas Pipeline ◽  
Pipeline System ◽  
Parameter Uncertainties ◽  
Simulation Results

One of the most significant systems that can be expressed by partial differential equations (PDEs) is the transmission pipeline system. To avoid the accidents that originated from oil and gas pipeline leakage, the exact location and quantity of leakage are required to be recognized. The designed goal is a leakage diagnosis based on the system model and the use of real data provided by transmission line systems. Nonlinear equations of the system have been extracted employing continuity and momentum equations. In this paper, the extended Kalman filter (EKF) is used to detect and locate the leakage and to attenuate the negative effects of measurement and process noises. Besides, a robust extended Kalman filter (REKF) is applied to compensate for the effect of parameter uncertainty. The quantity and the location of the occurred leakage are estimated along the pipeline. Simulation results show that REKF has better estimations of the leak and its location as compared with that of EKF. This filter is robust against process noise, measurement noise, parameter uncertainties, and guarantees a higher limit for the covariance of state estimation error as well. It is remarkable that simulation results are evaluated by OLGA software.

Adapted Methodology for Evaluating EOR Reserves and Resources, Incorporated and Applied at an Oil and Gas Company

2021 ◽  
Author(s):  
Lilibeth Chiquinquira Perdomo ◽  
Carlos Alvarez ◽  
Maria Edith Gracia ◽  
Guillermo Danilo Salomone ◽  
Gilberto Ventuirini ◽  
...  
Keyword(s):  
Oil And Gas ◽  
Large Body ◽  
Securities And Exchange Commission ◽  
Point Of View ◽  
Assessment Process ◽  
Pilot Projects ◽  
Oil Reserves ◽  
Track Record ◽  
Starting Point ◽  
Petroleum Resources

Abstract As other companies registered in the US stock market, the company reports oil and gas reserves, in compliance with the definitions of the Securities and Exchange Commission (SEC). In addition, it complies internally with the guidelines established by the Petroleum Resources Management System to certify its resources. The PRMS focuses on supporting consistent evaluation of oil resources based on technically sound industry practices, providing fundamental principles for the assessment and classification of oil reserves and resources, but does not provide specific guidance for the classification and categorization of quantities associated with IOR projects. Recently, the company has implemented EOR pilot projects, and their results seem to show commerciality for future development or expansion to new areas, displaying multiple opportunities and proposals to incorporate reserves and resources. So far, the pilot projects and their expansions have been addressed only from the point of view of incremental projects, as an improvement over the previous secondary recovery. The company does not have sufficient track record in booking reserves or resources from EOR projects, their quantities have been incorporated following bibliographic references and results of EOR projects with proven commerciality around the world. For this reason, the need arose to have a tool that provides the company with methodological criteria to evaluate the resources and reserves inherent in this type of project, that incorporate the "best practices" of the industry and that respect the guidelines and definitions of PRMS for incremental projects. That was how, the need to meet this challenging goal led company to develop its "EOR Resources and Reserves Assessment Guide" with the advice of a renowned consulting company. Although the Guide is not intended to be a review of the large body of existing IOR literature, it contains several useful references that serve as a starting point for understanding the IOR project for assessment process of resources and reserves. This document shows the process of development and implementation of the EOR guide, complementing the existing guides within the corporation and providing the company with a positive result within the internal processes of Audit, reserves and resources for this type of projects.

A System Based Approach to Achieve Long Term Integrity of Gas Facilities

2012 ◽  
Author(s):  
W. Sloterdijk ◽  
M. Hommes
Keyword(s):  
Oil And Gas ◽  
Life Time ◽  
Transmission Systems ◽  
Design Life ◽  
Design Build ◽  
Challenging Environment ◽  
Time Extension ◽  
Optimum Cost ◽  
New Facility

In today’s challenging environment, the priority for many oil and gas operation companies is to design, build and safely operate facilities at optimum cost efficiency. This means that new facility designs must consider critical facility integrity and that existing facilities are operated well beyond their intended design life. Main gas transmission systems are now some 50 years old and operate for longer periods than anticipated during design and construction for reasons such as; the transition to renewables with another 50 years of service foreseen, and; gas transmission systems that operate satisfactorily, have very low failure rates and for which the planned safe life time extension is expected to be the lowest cost option.

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