Risk Based Structural Integrity Management of Marine Platforms Using Bayesian Probabilistic Nets

2008 ◽  
Vol 131 (1) ◽  
Author(s):  
Roberto Montes-Iturrizaga ◽  
Ernesto Heredia-Zavoni ◽  
Francisco Vargas-Rodríguez ◽  
Michael Havbro Faber ◽  
Daniel Straub ◽  
...  
Keyword(s):  
General Framework ◽  
Structural Reliability ◽  
Structural Integrity ◽  
Structural Effect ◽  
Structural System ◽  
Probabilistic Networks ◽  
Suggested Approach ◽  
Integrity Management ◽  
Joint Consideration ◽  
Damage Processes

The present paper introduces a general framework for integrity management of offshore steel jacket structures allowing for the risk based planning of inspections and maintenance activities with a joint consideration of various relevant deterioration and damage processes. The suggested approach relates the relevant deterioration and damage processes to damage states, which in turn may be related to the overall integrity of the jacket structural system as measured through the reserve strength ratio. Each state of degradation, irrespective of the cause, can then be assessed in terms of their impact on the annual probability of failure for the structure. Based on data and subjective information regarding the annual probabilities of occurrence of the relevant deterioration and damage processes, together with a probabilistic modeling of the quality of condition control, it is possible to assess the structural effect of each type of deterioration and damage phenomenon. This facilitates the development of a general framework for risk based integrity management. In the present work such a framework is formulated using Bayesian probabilistic networks for evaluating the time varying global structural reliability of jackets subject to progressive deterioration of its members due to the combined effect of different sources of damage. In principle, system effects, i.e., the effect of damage in one element of the structural system on the capacity of other elements, can also be accounted for through a Bayesian probabilistic net; however, this is not considered in this work.

Risk Based Structural Integrity Management Using Bayesian Probabilistic Nets

2006 ◽  
Author(s):  
Roberto Montes-Iturrizaga ◽  
Ernesto Heredia-Zavoni ◽  
Enrique Marcial-Marti´nez ◽  
Michael Havbro Faber ◽  
Daniel Straub ◽  
...  
Keyword(s):  
General Framework ◽  
Structural Reliability ◽  
Structural Integrity ◽  
Suggested Approach ◽  
Annual Probability ◽  
Damage States ◽  
Jacket Structures ◽  
Integrity Management ◽  
Joint Consideration ◽  
Damage Processes

The present paper presents a general framework for integrity management of offshore steel jacket structures allowing for the risk based planning of inspections and maintenance activities with a joint consideration of all relevant deterioration and damage processes. The basic idea behind the suggested approach is to relate the relevant deterioration and damage processes, i.e. the exposure events, to damage states which in turn may be related to the overall integrity of the jacket structural system as measured through the Reserve Strength Ratio (RSR). This facilitates that any state of degradation, irrespective of the cause, can be assessed in terms of their impact on the annual probability of failure for the structure. Taking basis in data as well as subjective information regarding the annual occurrence probabilities of the relevant deterioration and damage processes, together with a probabilistic modeling of the quality of condition control, it is possible to assess the effect of condition control of each type of deterioration and damage phenomena. This then facilitates the development of a general framework for risk based integrity management. In the present work such a framework is formulated using Bayesian Probabilistic Nets (BPN) for evaluating the time varying global structural reliability of jackets subject to progressive deterioration of its members due to the combined effect of different sources of damage.

A Novel Approach to Improving the Structural Reliability of a Fixed Offshore Platform Subject to Wave-in-Deck Loading Using a Holistic Structural Integrity Management (SIM) TRIAD Approach

2020 ◽  
Author(s):  
Mehrdad Kimiaei ◽  
Jalal Mirzadeh ◽  
Partha Dev ◽  
Mike Efthymiou ◽  
Riaz Khan
Keyword(s):  
Structural Reliability ◽  
Structural Model ◽  
Structural Integrity ◽  
Reliability Assessment ◽  
Offshore Structures ◽  
Offshore Platform ◽  
Offshore Platforms ◽  
Effective Manner ◽  
Integrity Management ◽  
Fixed Offshore Platform

Abstract Fixed offshore platforms subject to wave-in-deck loading have historically encountered challenges in meeting target reliability levels. This has often resulted in costly subsea remediation, impacted platform occupancy levels or premature decommissioning of critical structural assets due to safety concerns. This paper addresses the long-standing industry challenge by presenting a novel structural reliability approach that involves converging the analytical behavior of a structure to its measured dynamic response for assessment. In this approach, called the Structural Integrity Management (SIM) TRIAD method, the platform model is calibrated based on the measured in-field platform natural frequencies using a structural health monitoring (SHM) system, so that the reliability assessment can be performed on a structural model whose stiffness is simulated as close to reality as possible. The methodology demonstrates the potential of unlocking structural capacity of offshore structures by removing conservatism normally associated with traditional reliability assessment methods, thus significantly improving the ability to achieve target structural reliability levels in a cost effective manner. The SIM TRIAD method has been implemented while assessing an existing fixed offshore platform subject to wave-in-deck loads, which is located in East Malaysian waters. It has enabled the facility operator to achieve acceptable target structural reliability and has assisted in developing an optimized risk-based inspection (RBI) plan for ensuring safe operations to end of asset field life. The methodology and findings of the assessment are presented in this paper to illustrate the benefits of the SIM TRIAD method.

Testing of Acoustic Emission Technology to Detect Cracks and Corrosion in the Marine Environment

2010 ◽  
Vol 26 (02) ◽  
pp. 106-110
Author(s):  
Ge Wang ◽  
Michael Lee ◽  
Chris Serratella ◽  
Stanley Botten ◽  
Sam Ternowchek ◽  
...  
Keyword(s):  
Acoustic Emission ◽  
Structural Integrity ◽  
Pilot Project ◽  
Development Project ◽  
Management Program ◽  
Pipeline System ◽  
Inspection Planning ◽  
Structural Degradation ◽  
Integrity Management ◽  
Acoustic Emission Technology

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.

A Hybrid Topside Structural Approach to the Management of Aging Fleet

2021 ◽  
Author(s):  
Biramarta Isnadi ◽  
Luong Ann Lee ◽  
Sok Mooi Ng ◽  
Ave Suhendra Suhaili ◽  
Quailid Rezza M Nasir ◽  
...  
Keyword(s):  
Structural Integrity ◽  
Metal Loss ◽  
Web Based ◽  
Strong Basis ◽  
Asset Risk ◽  
Risk Ranking ◽  
Design Life ◽  
Industry Standards ◽  
Integrity Management ◽  
Inspection Data

Abstract The objective of this paper is to demonstrate the best practices of Topside Structural Integrity Management for an aging fleet of more than 200 platforms with about 60% of which has exceeded the design life. PETRONAS as the operator, has established a Topside Structural Integrity Management (SIM) strategy to demonstrate fitness of the offshore topside structures through a hybrid philosophy of time-based inspection with risk-based maintenance, which is in compliance to API RP2SIM (2014) inspection requirements. This paper shares the data management, methodology, challenges and value creation of this strategy. The SIM process adopted in this work is in compliance with industry standards API RP2SIM, focusing on Data-Evaluation-Strategy-Program processes. The operator HSE Risk Matrix is adopted in risk ranking of the topside structures. The main elements considered in developing the risk ranking of the topside structures are the design and assessment compliance, inspection compliance and maintenance compliance. Effective methodology to register asset and inspection data capture was developed to expedite the readiness of Topside SIM for a large aging fleet. The Topside SIM is being codified in the operator web-based tool, Structural Integrity Compliance System (SICS). Identifying major hazards for topside structures were primarily achieved via data trending post implementation of Topside SIM. It was then concluded that metal loss as the major threat. Further study on effect of metal loss provides a strong basis to move from time-based maintenance towards risk-based maintenance. Risk ranking of the assets allow the operator to prioritize resources while managing the risk within ALARP level. Current technologies such as drone and mobile inspection tools are deployed to expedite inspection findings and reporting processes. The data from the mobile inspection tool is directly fed into the web based SICS to allow reclassification of asset risk and anomalies management.

Evaluation of the Effect of Yield to Tensile (Y/T) Ratio on the Structural Integrity of Offshore Pipeline by Limit State Design Approach

2006 ◽  
Author(s):  
Gianluca Mannucci ◽  
Giuliano Malatesta ◽  
Giuseppe Demofonti ◽  
Marco Tivelli ◽  
Hector Quintanilla ◽  
...  
Keyword(s):  
Structural Reliability ◽  
Failure Modes ◽  
Structural Integrity ◽  
Limit State ◽  
Minor Effect ◽  
Offshore Pipelines ◽  
Limit State Design ◽  
A Minor ◽  
Probabilistic Failure Analysis ◽  
Failure Probabilities

Nowadays specifications require strict Yield to Tensile ratio limitation, nevertheless a fully accepted engineering assessment of its influence on pipeline integrity is still lacking. Probabilistic analysis based on structural reliability approach (Limit State Design, LSD) aimed at quantifying the yield to tensile strength ratio (Y/T) influence on failure probabilities of offshore pipelines was made. In particular, Tenaris seamless pipe data were used as input for the probabilistic failure analysis. The LSD approach has been applied to two actual deepwater design cases that have been on purpose selected, and the most relevant failure modes have been considered. Main result of the work is that the quantitative effect of the Y/T ratio on failure probabilities of a deepwater pipeline resulted not so big as expected; it has a minor effect, especially when Y only governs failure modes.

scholarly journals Integrity Management of Marine Structures; With Emphasis on Design for Structural Robustness

2018 ◽  
Author(s):  
Torgeir Moan
Keyword(s):  
Structural Damage ◽  
Structural Integrity ◽  
Oil And Gas ◽  
Offshore Structures ◽  
Design Standards ◽  
Limit States ◽  
Fabrication Errors ◽  
Integrity Management ◽  
Operational Errors ◽  
And Control

Based on relevant accident experiences with oil and gas platforms, a brief overview of structural integrity management of offshore structures is given; including an account of adequate design criteria, inspection, repair and maintenance as well as quality assurance and control of the engineering processes. The focus is on developing research based design standards for Accidental Collapse Limit States to ensure robustness or damage tolerance in view damage caused by accidental loads due to operational errors and to some extent abnormal structural damage due to fabrication errors. Moreover, it is suggested to provide robustness in cases where the structural performance is sensitive to uncertain parameters. The use of risk assessment to aid decisions in lieu of uncertainties affecting the performance of novel and existing offshore structures, is briefly addressed.

An External Corrosion Direct Assessment Module for a Pipeline Integrity Management System

2006 ◽  
Author(s):  
Menno T. van Os ◽  
Piet van Mastrigt ◽  
Andrew Francis
Keyword(s):  
Management System ◽  
Structural Reliability ◽  
Individual Performance ◽  
Corrosion Activity ◽  
Time Saving ◽  
Survey Techniques ◽  
Direct Assessment ◽  
Integrity Management ◽  
External Corrosion ◽  
The Individual

A significant part of the high pressure gas transport system of Gasunie cannot be examined by in-line inspection techniques. To ensure safe operation of these pipelines, an External Corrosion Direct Assessment (ECDA) module for PIMSLIDER (a pipeline integrity management system) is currently under development. The functional specifications of this module are based on NACE RP0502-2002, a recommended practice for ECDA. In addition to this, a new probabilistic methodology has been adopted, to take account for uncertainties associated with ECDA and to quantify the contributions from aboveground surveys and excavations to the integrity of a pipeline. This methodology, which is based on Structural Reliability Analysis (SRA) and Bayesian updating techniques, is presented in more detail in paper IPC2006-10092 of this conference. The DA module of PIMSLIDER enables computerized storage, retrieval and processing of all appropriate pipeline data and therefore guarantees highly accurate, reproducible and time saving integrity analyses of the Gasunie grid. Another important function of this system is the ability to use the complete database of all pipelines to pre-assess the integrity of a particular pipeline. This automated retrieval of data from pipelines with similar characteristics and/or environmental conditions results in a substantial increase of accessible data and enables Gasunie to improve the reliability of applied statistics throughout the process. As a consequence, the overall cost of inspections and excavations can be greatly reduced. In the Pre-Assessment phase, the DA module assists the integrity manager in gathering and analyzing data necessary to determine the current condition of a pipeline. After collection and visualization of the available data, the user can identify suitable ECDA regions. Furthermore, the gathered data are used to construct prior distributions of parameters relevant to the SRA model, such as the number and size of corrosion defects and pipeline-related parameters. In the Indirect Inspections step, the DA module allows the user to store and analyze the data from aboveground surveys, in order to identify and define the severity of coating faults and areas at which corrosion activity may occur. The probabilistic methodology accounts for the individual performance of each applied survey technique in terms of missed defects and false indications, in general a major source of uncertainty in ECDA. In the Direct Examinations phase, excavations are carried out to collect data to assess possible corrosion activity. Subsequently, the ECDA module uses this information to update, among other things, the parameters concerning the performance of survey techniques, the number of defects and the corrosion rate. As a result, updated failure frequencies are calculated for each ECDA-region (after each excavation if required), which are then used by the DA module to advise the integrity manager if additional mitigating activities are necessary, or by defining a reassessment interval.

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