Two instrumental series of events in the past several years have provided the impetus for API Subcommittee 2 (SC 2) to action a new strategy for the API Series 2 standards. Beginning in the early 1990's, with the formation of ISO TC 67 / SC 7 and subsequent development of the ISO 19900 series of standards for offshore structures, API started to map a long term strategy for the API documents, while actively participating in the preparation of the ISO suite. As a part of the Gulf of Mexico infrastructure response to the hurricanes Ivan, Katrina and Rita, API chartered the Hurricane Evaluation and Assessment Team (HEAT) to assess adequacy of existing standards and provide recommendations for modifying provisions in the standards. While aggressively pursuing in 2006 and 2007 the publication of six documents related to hurricane issues, and in consideration of the progressive publication of the ISO 19900 series documents. API SC 2 leadership developed a strategy to restructure the content of its standards to align more closely with the ISO document portfolio subdivided in general standards and the structural form standards, and providing thus a more straight forward approach in making updates to the technical provisions impacting multiple standards. The ISO Offshore Structures suite of standards consists of more than a dozen documents organized in two categories, first, guidance and requirements for technical disciplines common to more than one functional concept and secondly, guidance and requirements for the various concepts. With more than half the standards now published and nearly 80% to be published by 2009, baseline practices for many offshore structural facilities will utilize these standards in the near future. In fact, following the publication of the ISO standards, many regions of the world are expected to adopt them as a basis for offshore platform design. This paper outlines the plan to be implemented over the next few years concerning the restructuring sequence, alignment and merging of the ISO standards and API standards, and highlights benefits and challenges of this strategy. Introduction The development of offshore structures standards is an interesting and complex blend of pushing new technical boundaries, reacting to the consequences of some significant natural events and aligning with economic and safety initiatives. In the case of the offshore structure standards, some of the work has piggy-backed upon the more general standards initiatives while other activities are more specifically related to offshore conditions, e.g. damage due to hurricanes passing over a number of offshore facilities. Standards have often become a focal point of interest following a defining event, such as Hurricane Hilda in the 1960's, or in conjunction with the time when a product or industry has headed toward commodity status, as illustrated by the initiation of the API standards activities in the 1920's. In the past half-century, standards have often been driven, either directly or indirectly, by legislative or regulatory directives. The offshore structures standards were event driven in the beginning and both event and legislative/economic driven today. The path to having a single set of globally applicable standards is an outgrowth of the political and legislative process establishing the European Union. This " event?? drove what were initially regional standards with some global applicability to collaboratively bringing regional efforts into a single coherent direction. Though regional activity still exists today in the European Union, much of it is coordinated to produce a single set of standards.
This paper was salected for presentation by the OTC Program Commillee following _iew of information contained in an abstract submilled by the author(S). Contents of the paper, as presented, have not been reviewed by the Offshora Tectv\oIogy Conference and era subject to correction by the llUlhor(s). The mlllllrilll, as presentad, does not Il8C88sarily reflect any posijion of the Offshore Tachnology Conference or ijs otflC8f$. Elec:lronic reproduction, distribution, or storage of any part of Ihis paper for commercial purposes wijhout the wrillen consent of the 0ffIh0re Tachnology Conference is prohibited. Pennillion to reproduce in print is restricted to an abstnlCl of not mora than 300 words; illustrations may not be copied. The abstract must contain conspicuous acknowledgment of where and by whom the paper was presented. AbstractAn overview of the historical evolution of the design of fixed steel offshore structures and the inter-related development of API RP 2Aand the ISO Fixed Steel Standard is provided from the beginnings of the industry in 1947 to projections and a vision for a path forward. The trends, events and drivers impacting the design aspects will be addressed.
During the late 1980's it became evident that an API process was required for assessing the structural integrity of existing jacket platforms in the US OCS. The approach would be different from the design of new platforms and as such required a new section of API RP 2A. The offshore community then established an API working group that developed the assessment approach and released it in the mid 1990's as "API RP 2A, Section 17 - Assessment of Existing Platforms." The background and assumptions of Section 17 are described in a series of 1994 OTC papers. Since then, Section 17 has become the worldwide recognized approach for assessing existing platforms. It has been used many times around the world and particularly in the Gulf of Mexico. In August 2003, the MMS released an NTL requiring Gulf of Mexico platform owners to assess their platforms to Section 17 requirements. This paper provides further background, clarifications and proposed updates to Section 17. The paper is divided into three parts. Part I is a discussion on the background and perspective on why and how Section 17 was originally developed including review of some of the basic premises of the document. Part II is a historical perspective on how Section 17 has been implemented over the past seven years, and how platforms that applied the process have performed, including during Hurricane Lili. Part III presents the planned future of Section 17 and proposed clarifications and updates. Part I: The Development of Section 17 The offshore industry started in the Gulf of Mexico in the late 1940's. Drilling and production grew steadily into the 1960's. In the frontier environment where little was know about the details of wave heights and wave loadings, land based practices were extrapolated with apparent success. Various oil companies and contractors developed staffs and procedures to design, install and operate the necessary facilities. The industry had continued success until the early 1960â??s when Hurricanes Hilda in 1964 and Betsy in 1965 swept through the Gulf of Mexico resulting a considerable damage to and loss of a number of platforms. These were the first large scale ("full population") hurricanes that the industry had experienced and it was evident that some guidance was required for platform design. The First API Recommended Practice Following Hurricane Hilda, a group of industry leaders met to discuss issues related to design practice (13). Discussions of return periods for design wave height were one of the key topics. Considerable variance, from 25 year to 100 year periods, was confirmed along with a wide variety of techniques and data for determining the height for a given return period. Additional topics of key importance identified were steel design and foundation characteristics. More important than the actual topics discussed, was the long term result of the meeting. This group of more than 60 met in November 1964 and held what became the first meeting that eventually led to the issuance of the first design guidance for offshore facilities, the API Recommended Practice for the Planning, Design, and Construction Fixed Offshore Platforms in 1969, a 16 page document (11).
This paper provides an overview of the current efforts of API to provide an overarching standard within the API Series 2 standards for the design and construction of offshore structures which would be similar to ISO 19900. The paper provides a historical perspective of the current suite of API standards, discussion of the current practices, current issues in the proposed standard (referred to as API RP 2GEN), and future plans.Offshore structures are designed according to ISO / API standards. The ISO 19901 series lists specific requirements for design, construction and operation of offshore facilities with provisions that are applicable to different facility types (fixed, floating, or arctic structures), different materials and the possible range of operating environments. The structure-dependent requirements for various types of offshore facilities are listed in ISO 19902-19906 and corresponding API series.The ISO / API standards for offshore structures generally follow reliability-based design, i.e. the design procedures have been developed or calibrated to ensure minimum target reliability levels depending on the life safety, environmental and economic consequence of failure. It is important to recognize that ISO / API procedures enforce minimum standards on a wide range of assumptions and activities: description of actions, modeling and simulation of action scenarios, structural or global analysis, design rules, model testing, workmanship, quality control etc. Hence the modification of one or more aspects of design standards can disturb the delicate balance in the design and lead to unintended consequences in the target reliabilities.The main objective of API 2GEN standard is to introduce consistency in terms / definitions / assumptions and high level requirements, with special emphasis on those that are used in setting design reliability targets in the lower level ISO / API documents. The API committee that is developing API 2GEN is recommending several new definitions related to exposure levels and ULS / ALS requirements. The emphasis of the committee recommendations is on conditions applicable to the Gulf of Mexico (GOM), e.g. shut-in of the wells and evacuation of personnel ahead of forecasted hurricanes Background - Structure of StandardsThe history of the API series of offshore structures standards, Recommended Practices (RPs), Specifications (Specs) and Bulletins began in the 1960's and has been well documented (1) (2). The first standard was API RP 2A released in 1967 focusing on fixed steel jackets and decks. The RP was quite expansive in scope covering steel member design, hydrodynamic loading (wind/wave/current), soils and foundations, fabrication, etc. Starting as a 16 page document, the RP rapidly expanded as the industry matured to well over 200 pages by the early 1990s and included additional topics such as inspections, installation, welding, etc. With the relative complete coverage of areas such as metocean, foundations and seismic, other API documents, such as RP 2T (Tension Leg Platforms), 2...
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