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Abstract Hurricane Roxanne is marked in the history of Bay of Campeche as one of the most severe storms that hit the zone during this century, and therefore questioned the validity of the design criteria applied at that time. As a consequence, a newborn own risk based criteria was developed for design and assessment of submarine pipelines and platforms in Bay of Campeche. Petrรณleos Mexicanos (PEMEX) and Instituto Mexicano del Petrรณleo (IMP) developed and issued such criteria in 1998, named Offshore Pipeline Transitory Criteria. The Transitory Criteria is based on risk assessment and management approach. It is intended in this paper to show the result obtained so far of that development. Safety and serviceability categories for pipelines are defined. Safety factors for design and reassessment of wall thickness by internal pressure are determined based on risk approach. Practice recommendations for the design and requalification for hydrodynamic stability of submarine pipelines and risers are established. Safety factors for hydrodynamic stability are obtained following this criteria, and oceanographic characterization of the Bay of Campeche are presented in easy-reading charts for design and requalification. Introduction Hurricane Roxanne, which it is marked in the history of Bay of Campeche (BOC), Gulf of Mexico, as one of the most severe storm ever that hit the zone during this century, questioned one more time that the design criteria applied at that time showed some deficiency. As a consequence, an own risk based criteria was developed for design and assessment of submarine pipelines and platforms in BOC. PEMEX and IMP developed and issued such criteria in 1998. Thus, PEMEX elected to develop pipeline requalification guidelines specifically for BOC conditions. IMP engineering was called on by PEMEX to direct and lead these developments. The new criteria and guidelines were to be based on the work that Prof. Robert G. Bea from the University of California in Berkeley developed specifically for BOC conditions and the best of the technology incorporated into the existing guidelines (Bea, 1997). A two year intensive work was required before the first edition of the criteria and guidelines, named Transitory Criteria (TC). This paper addresses categorization of pipeline for serviceability and safety, wall thickness safety factors due to internal pressure, oceanographic characterization of BOC and hydrodynamic stability safety factors that must be used in a submarine pipeline for design or requalification in the BOC. Risk Study and Failure Probability The risk study was conducted by taking into account the economical aspect, historical behaviour, and recommendations of international codes in order to determine the failure probability of pipelines corresponding to design and requalification. Cost-Benefit Analysis. The economic analysis for obtaining the failure probability took into consideration the initial cost of design and construction, and the cost of failure (lost of production, facilities damages, and lost of human lives). The optimum failure probability (Pfo) is the failure probability that produces the lowest expected total cost. This probability (Pfo) defines the acceptable, and desirable probability of failure for the design of new pipelines. Cost-Benefit Analysis. The economic analysis for obtaining the failure probability took into consideration the initial cost of design and construction, and the cost of failure (lost of production, facilities damages, and lost of human lives). The optimum failure probability (Pfo) is the failure probability that produces the lowest expected total cost. This probability (Pfo) defines the acceptable, and desirable probability of failure for the design of new pipelines.
- North America > Mexico > Gulf of Mexico > Bay of Campeche (1.00)
- North America > Mexico > Campeche (1.00)
- Government > Regional Government > North America Government > Mexico Government (1.00)
- Energy > Oil & Gas > Midstream (1.00)
- North America > Mexico > Gulf of Mexico > Bay of Campeche (0.89)
- Europe > United Kingdom > North Sea > Southern North Sea > Southern Gas Basin > Silver Pit Basin > Block 49/30c > Davy Fields > Brown Field > Rotliegend Formation (0.89)
ABSTRACT Experience has amply demonstrated that Human and Organization Factors (HOF) play important roles in determining the quality and reliability of marine structures such as ships, pipelines, and offshore platforms. This paper addresses HOF in tile contexts of approaches, assessments, and general guides that are intended to help improve the quality, safety, and reliabilityy of offshore platforms. These elements areintended to primarily address potentially critical situations involving HOF that can lead to major degradations in the quality of offshore platforms.. INTRODUCTION Experience with offshore platforms has amply demonstrated that the primary hazards to the quality, safety, and reliability of these systems are associated with the actions and inactions of the people that are involved with the design, construction, and operations of these systems. Our research on marine systems clearly shows that roughly 80 % of the manor compromises in quality can be attributed to HOF. About 80 % of these ompromises occur during operations. However, many of these operational compromises have antecedents embedded in design and construction.4 These tindings are similar to those found in a wide variety of nonmarine systems and communities.4. Experience also has amply demonstrated that traditional methods and approaches to help assure that desirable quality, safety, and reliability are developed work in the vast majority of cases. It is the rare, low probability, high consequence situations involving HOF that areslipping through the Quality Assurance and Quality Control (QA / QC) processes and associated management strategies (e.g. Total Quality Management). In themain, the contents of this paper are intended to address what is not addressed by traditional quality management activities and strategies to help assure desirable and acceptable quality in offshore platforms. The contents of this paper represent a summary of some of the key results from six years of research that have addressed the life-cycle quality, safety, and reliability aspects of a wide variety of both marine and non-marine systems. is work has involved field studies inwhich attempts have been made to apply, verify, and test the results of the research. The work includes in depth studies of information contained in major marine systems accident data bases. It continues to focus on HOF in design, construction, and operation of marine systems including platforms, pipelines, and commercial tankers. This paper does not chronicle a mature technology. There is a long way to go before this technology can be called mature. Thanks to the progress made by non marine communities such as the commercial air transportation and nuclear power plant industries, acoherent and meaningful start on the unique challenges associated with HOF in the marine community has been made. The approaches and assessment strategies outlinwl here can help those with front-line responsibilities for offshore platforms and their operations to better chieve desirable quality, safety, and reliability.. In the remainder of this paper, fiit we define quality, safety, and reliability to show how they are inter-related. This is done so that the objectives of work to improve HOF will be clear and balanced.
- Europe > United Kingdom (1.00)
- North America > United States > California (0.47)
- North America > United States > Texas > Harris County > Houston (0.28)
- Government > Regional Government > North America Government > United States Government (1.00)
- Energy > Oil & Gas > Upstream (1.00)
- Europe > Norway > North Sea > Central North Sea > South Viking Graben > Sleipner Field > Draupne Formation (0.99)
- South America > Brazil > Parnaiba Basin > Block PN-T-68 > California Field (0.89)
- Asia > Middle East > Israel > Tel Aviv District > Southern Levant Basin > National Field (0.89)
Abstract The MCAPS project was aimed at providing engineers and managers with a tool for comparison of alternative production concepts based on a risk assessment approach. The approach extends the usual economic comparison to include random accidental and failure costs, in addition to personnel and spill risk consequences. The MCAPS methodology is a full scope, life cycle risk assessment procedure targeted at offshore production systems. The benefits include an improved understanding of risk mechanisms, identification and mitigation of hazards, improved cost-effectiveness of design, and improved safety. Observations are made concerning quantitative risk analysis, present worth values, risk costs, and notional veraus actuarial risks. Introduction Background Considerable skepticism concerning the usefulness of probabilistic risk assessment was evident at an internationalworkshop on application of risk analysis to offshore operations held at the National Institute of Standards and Technology (NIST) in 1984 (Ref. 1). A different experience was provided at a similar workshop held at NIST in 1991, where the main issue was not whether to use these stu. dies, but how they should be utilized most effectively. This is an important shit% in emphasis. However, conditions in 1991 were not the same as they were in 1984Several fires and explosions have occurred on platforms, Piper Alpha being the best known. Recommendations made by Lord Cullen in the Piper Alpha inquiry report (Ref. 2) caused a change in the UK regulatory regime to a risk management and riskassessment basis, largely in parallel with the Norwegian regulatory regime (Ref. 3 and Ref. 4). The application of risk assessment in a regulatory context is extensive in the United Kingdom and Norway. Such application is discussed in Ref. 5. The MCAPS project has to be evaluated in the context of these important differences. The project was initiatedin 1987 and carried out in 1988 and 1989, with participation by 18 organizations including oil companies, regulatory agencies and engineering contractors. Thefinal project report was presented in 1990 (Ref. 6). Objectives The MCAPS methodology is an engineering procedure that can assist the process of making rational comparisons among design alternatives for offshore production systems. Currently, such comparisons are often made primarily on the basis of initial cost estimates without explicit consideration of risks and related life cycle costs, which can be several times the initial costs. Use is made of recent developments in structural system reliability and full scope risk assessment. The latter includes consideration of identifiable hazards to the operation, including those involving the riser and well systems, production and utility equipment, and the environment.
- Europe > United Kingdom (0.88)
- North America > United States > Texas (0.28)
- Energy > Oil & Gas > Upstream (1.00)
- Government > Regional Government > North America Government > United States Government (0.48)
- Europe > United Kingdom (0.89)
- Europe > Norway (0.89)
ABSTRACT Characterization and definition of an acceptable reliability for offshore platforms is a pivotal part of development of design and re-assessment criteria for such structures. This paper outlines several complementary engineering approaches to develop background to reach judgments concerning reliability targets for offshore platforms. These approaches are illustrated with development of reliability targets for design of new and re-qualification of existing PDQ (production-drilling-quarters) platforms. INTRODUCTION Uncertainties result in risks. Risks are an unavoidable reality of any activity. Risks associated with an activity can be reduced to zero only by eliminating the activity. Given that one does not want to abandon the activity, a decision must be reached on how much risk one is willing to take or tolerate. Risks can be expressed as the product of the likelihood of a hazardous event (associated with an activity), and the consequences that could be associated with that event. The consequences can involve property losses, injuries and fatalities, resource losses, productivity or utility losses, and general environmental injuries. Every source of risk can be reduced, and safety increased, by reducing the likelihood of a hazardous event, and/or by reducing the potential consequences associated with the hazardous event. Risks can be reduced only by a considerable expenditure of human effort, materials, services, and other resources. The amount of resources that can be expended on increasing safety is unlimited. However, the resource supply is finite. In addition, the resources are subject to many other competing demands In the context of offshore platforms, one shouldbe prepared to address two choices. First. one should be prepared to choose what risks will be tolerated or accepted. Second, one should be prepared to choose how and how much resources one is willing to invest to achieve the risks that will be tolerated. RISK-DECISION EVALUATIONS In a public-regulatory evaluation of risk, the public-regulatory responsibilities pertain primarily to life safety (injuries and fatalities), resource development, productivity, monetary stability, quality of life, and environmental protections, The primary focus should be from the standpoint of benefits and risks of the public. In the industrial framework, the same factors must be taken into account, but with a smaller segment of the public with its primary focus. In this case, the primary focus should be the benefits and risks to the stockholders and employees of the company. Both the society (country) and industry, in thelong run, must be profitable. That is, their production (value of goods and services) must exceed their costs (resources required for production). If this is not the case, then they will sooner or later go out of business (become bankrupt). Financial stability is dependent on profitability; just as the resources required for safety are dependent on profitability. In the past, the risks associated with alternative activities have been evaluated primarily on the basis of experience and judgment. If the activity failed, by experience, to provide a tolerable balance of risks and benefits, then the activity was re-evaluated, and changed, until a tolerable balance was achieved.
- Europe > United Kingdom > England (0.28)
- North America > United States > Texas (0.28)
- Health & Medicine (1.00)
- Energy > Oil & Gas > Upstream (1.00)
- North America > Cuba > Gulf of Mexico (0.89)
- Europe > United Kingdom > North Sea (0.89)
- Europe > Norway > North Sea (0.89)
- (2 more...)
How high should the design wave be? What magnitude of earthquake should be allowed for? Such questions daily confront the platform designer, the owner, and the code -writer. Here is a philosophy, logic, and computational framework in which design criteria can be examined and selected. Introduction This paper is written for the engineer, platform owner, or design code writer faced with deciding what environmental criteria will be used for offshore platform designs. It is written within the context platform designs. It is written within the context of presently applied design and analysis techniques. The paper has a simple message: A logical and quantitative method is available to assist in the selection of design criteria. The method is not a panacea and does not represent scientific precision. panacea and does not represent scientific precision. It is limited by the data, engineering, experience, and judgment that attend it. To assist in expressing the concepts involved, a specific example will be used. A template-type drilling and production platform is the study model (see Fig. 1). The platform sits in 300 ft of water. It is assumed that the critical forces on the platform are those lateral forces developed by waves. Different platform types and other environmental factors may platform types and other environmental factors may be considered in the method discussed. Lifetime-Plus Method Generally, one must be dissatisfied with existing conditions before he will consider changing them. At present, the most common method of selecting design present, the most common method of selecting design wave heights is the Lifetime-Plus method. Using this method, one decides on the maximum service life of the platform, and then designs for the most probable maximum wave heights that will be experienced during that life. If experience, lack of experience, or intuition indicates that the design wave is not big enough, the "plus" comes in and larger design waves are specified. The Lifetime-Plus method has served the offshore industry long and well. However, it is known to suffer from at least three major deficiencies:It fails to quantitatively recognize the possibilities and consequences of experiencing waves possibilities and consequences of experiencing waves both larger and smaller than that used in design. It fails to quantitatively recognize the strengths and weaknesses in platforms intended to resist the wave forces. It fails to place any limits on the "plus" part of the method. In general, one wants benefits (failures prevented) to equal or exceed the costs. The prevented) to equal or exceed the costs. The Lifetime-Plus method has no means for recognizing benefits, costs, or the point at which a balance between those is reached. Dissatisfaction alone seldom justifies change. One must have something to change to that will be an improvement. The method outlined in the next section is proposed as a significant improvement over the Lifetime-Plus method. Reliability Analysis Method The method to be discussed in the remainder of this paper will be called a Reliability Analysis. Such an paper will be called a Reliability Analysis. Such an analysis is a logic framework in which the uncertain and variable aspects of loads and platform strengths are quantified and examined. JPT P. 1206
- North America > United States > Alaska > Arctic Ocean > Arctic Basin > Amerasia Basin > Canadian Basin (0.89)
- Europe > United Kingdom > North Sea > Northern North Sea > Northern North Sea Basin (0.89)
- Europe > Norway > North Sea > Northern North Sea > Northern North Sea Basin (0.89)
ABSTRACT The selection or specification of environmental criteria is one of the crucial steps in engineering offshore structures. In the various offshore areas the engineer is confronted with combinations of forces resulting from wind, waves, currents, earthquakes, ice, and submarine slides. Often, the selection of criteria for these forces must be done with scanty information. In the light of the 'unknowns and the natural variabilities of the environment, the rational selection of design criteria is not a simple problem. What has been termed as the "design criteria muddle" is one of the most pressing and controversial topics in both mobile rig and permanent platform design for newly developing offshore areas. This paper attempts to develop a philosophy, logic, and computational framework in which design criteria can be selected, specified, or at least discussed. Two primary concepts are involved:Uncertainty, variability and the resultant hazards of potential platform failures caused by the environment are an unavoidable reality. The hazards can only be minimized or, more realistically, the safety of the structures optimized to a degree consistent with available information and the justified investment of money. The selection of environmental criteria should include an integrated consideration of the function, strength, reliability, and cost of the structures which will operate in the environment. INTRODUCTION This paper is written for the engineer, platform owner, or design code writer faced with deciding what environmental criteria will be used for offshore platform designs. It is written within the context of presently applied design and analysis techniques. The paper has a simple message: a logical and quantitative method is available to assist in the selection of design criteria. The method is not a panacea and does not represent scientific precision. It is limited by the data, engineering, experience, and judgement which are input. To assist in expressing the concepts involved, a specific example will be used. A template-type, drilling and production platform will be the study model (see Figure 1). The platform will be located in 300 feet of water. It will be assumed that the critical forces on the platform are those lateral forces developed by waves. Consideration of different platform types and other environmental parameters is within the scope of the method discussed. LIFETIME-PLUS METHOD Generally, one has to be dissatisfied with the present state of affairs to warrant consideration of a change from that state. At present, the most common method of selecting design wave heights is the Lifetime Plus Method. Using this method, one decides on the maximum service life of the platform, and then designs for a wave height that is the most probable maximum that will be experienced during the life. If experience, lack of experience, or intuition indicates that the design wave is not big enough, the "plus" comes in and larger design waves are specified.
- North America > United States > Alaska > Arctic Ocean > Arctic Basin > Amerasia Basin > Canadian Basin (0.89)
- Europe > United Kingdom > North Sea > Northern North Sea > Northern North Sea Basin (0.89)
- Europe > Norway > North Sea > Northern North Sea > Northern North Sea Basin (0.89)