Risk Assessment and Management (RAM) based criteria for the design and requalification of pipelines and risers in the Bay of Campeche have been developed and implemented by PEMEX and IMP. The criteria address pipeline pressure integrity and corrosion, hydrodynamic stability, and capacity to withstand movements of the sea floor soils (the soft sea floor soils in the Bay of Campeche develop significant motions during hurricanes). The pipelines are assessed for three Safety and Serviceability Classifications. The SSC are based on risk acceptance criteria derived from considerations of economics, historic performance of pipelines, and current standards-of practice. Desirable and acceptable reliabilities of the pipelines for the three conditions cited are defined. Reliability formulations of pipeline 'demands' and 'capacities' are developed for loss of containment integrity due to corrosion, and hydrodynamic instability. Design for corrosion is linked to Inspection, Maintenance, and Repair (IMR) programs that will be implemented to manage corrosion. Uncertainties and biases associated with the analytical procedures are evaluated. Given the risk based characterizations, the reliability formulations, and the assessments of uncertainties and biases, design and requalification criteria are defined. Introduction At the present time, there are more than 500 km of pipelines located in the Bay of Campeche. These pipelines transport in excess of 2 million barrels of oil and 1.5 billion cubic feet of gas per day. The majority of the pipelines are located in water depths between 30 m and 50 m. Most of these pipelines were installed in the 1980's and 1990's, with some pipelines installed in the late 1970's. In October 1995, hurricane Roxanne formed in the western Caribbean Sea, crossed the Yucatan Peninsula, and entered the Bay of Campeche. Due to a southward moving front, the hurricane did not follow the normal northerly path of most hurricanes. It was forced back into the Bay of Campeche and the eastern coast of Mexico where it did considerable damage. Roxanne was the most severe hurricane to affect the Bay of Campeche during this century. It generated environmental conditions which approximated those of 100-year return period hurricanes.1 The majority of damage was confined to pipelines.2 Pipeline damage consisted of broken and leaking connections (above and under water), and damaged weight coatings. Given the results from the pipeline inspections and fitness for purpose studies, PEMEX and IMP initiated development of Risk Assessment and Management (RAM) based criteria for design and requalification of the pipelines in the Bay of Campeche. The RAM based criteria was to take advantage of the results from the oceanographic, pipeline design and inspections. and fitness for purpose studies, recent results from studI.es conducted by DNV3, AG4A, ISO5, BSI6, and API7 to develop advanced criteria for design of new pipelines and assessment of existing pipelines. Probability based reliability methods were used to evaluate the full scope (environmental and operating hazards), life-cycle (design, construction, operations, maintenance, decommissioning) risk characteristics associated with the Bay of Campeche pipelines (Risk Assessment).8–15 PEMEX and IMP utilized advanced risk management and decision analysis methods to define how the criteria should be defined to develop acceptable risks (Management).11,16,17

This peper wes selected for presentation by the OTC Program Commillee following review of informetion oontained in en ebstrect subm~ted by the euthor(s). Contents of the peper, as presented, heve not been reviewed by the Offshore Technology Conference end are subject to correction by the euthor(s). The materiel, as presented, does not necessarily reflect eny position of the OffShore Technology Conference or its officers. Electronic reproduction, distribution, or storage of eny part of this peper for commerciel purposes without the wr~ten oonsent of the OffshOre Technology Conference is prohib~ed. Permission to reproduce in print is restricted to en ebstrect of not more than 300 words; illustrations may not be oopied. The abstrect must contain oonspicuous acknowledgment of where and by whom the paper was presented.85 and characterizations associated with interactions of the hurricane waves with the soft sea floor soils, wave-in-deck forces, the capacities of new, damaged, and repaired tubular joints, the fatigue of tubular joints and appurtenances, and the stiffness and capacities of laterally and axially loaded piles. Working Stress Design (WSD), Load and Resistance Factor Design (LRFD), and Ultimate Limit State (ULS) platform design and requalification guidelines were developed. This paper summarizes the guidelines that were developed for hurricane ULS and WSD evaluations. This study could not have been performed, completed, or have probed as deeply as it did into the multitude of important issues without the assistance, encouragement, and advice of IMP engineering team including

Tubular joints are integral components of offshore structures and as such, many codes and standards address their design. The fatigue damage process of tubular joints in offshore structures is inherently variable and uncertain. In addition, potentially, there are important bias and uncertainties introduced by the analytical models used in design codes and standards. Therefore, in the development of reliability based fatigue design and requalification criteria, it is important to recognize these differences and to develop the best estimates of joint fatigue durability.This paper summarizes a study to identify the primary sources of bias and uncertainty associated with assessment of fatigue lives of tubular joints in offshore platforms. Based on the extensive screened test data, the important uncertainty sources of tubular joint fatigue durability has been examined, and the uncertainty models are developed to facilitate development of reliability based fatigue design and requalification criteria and fatigue inspection guidelines for tubular joints in offshore platforms.

Petroleos Mexicano (PEMEX) and Instituto Mexicano del Petroleo (IMP) have developed and issued Transitory Criteria for reassessment and requalification of platforms and pipelines in the Bay of Campeche (1998). The purpose of this paper is to highlight some of the key issues that were associated with development of the PEMEX-IMP guidelines and to identify some of the future efforts that are intended to extend the technology of platform reassessment and requalifications. It is hoped that the open exchange and discussion of this experience will help promote worldwide cooperation and development of this important technology. [S0892-7219(00)00801-3]

In October 1995 Hurricane Roxanne damaged offshore installations in the Bay of Campeche. To assess the condition of significant pipelines. a major inspection program involving over 450 km of pipelines was conducted to survey the location of the pipelines and to determine their relationship to the seabed. Lines not fully buried were visually inspected by multiple video cameras. The results of the inspections were presented on charts, data files and video tapes. These results were utilized along with existing design information to assess the condition of the pipelines and to identify locations where remedial work was needed. The hydrodynamic stability of all exposed pipelines was analyzed to determine the need for pipeline burial. Damage to the pipes, weight coatings and corrosion protection systems was analyzed on a case-by-case basis. 'The paper will review the pipeline inspection objectives, procedures, and results. Evaluation procedures using this information will be described along with a summary of the conclusions of the study. This is one of the largest and most comprehensive evaluations of existing pipelines ever conducted worldwide and provides a model for future evaluations of aging or damaged pipelines. The improved location and condition information provide a sound basis for appropriate maintenance and operational planning for these lines. Introduction When hurricane Roxanne passed through the Bay of Campeche in 1995, the area's petroleum production infrastructure experienced extreme environmental conditions that put the physical integrity of the pipeline systems at risk. Pipeline failures caused by this event had a considerable financial impact. These failures were identified and repaired shortly after the hurricane in most cases.@ After an event like hurricane Roxanne, an assessment of the condition of the pipeline systems that were damaged or of strategic importance was needed. In order to make an assessment, through inspections of selected submarine pipelines and risers were needed in order to obtain detailed information about the condition of the system and to identify damage caused by the hurricane not associated with obvious failures.@ In order to properly evaluate the condition of the facilities it was also necessary to determine if the existing metocean criteria used to design the facilities needed to be revised. To achieve this purpose, a hindcast was needed of the weather and sea state conditions during the passage of hurricane Roxanne. Hindcasts were also needed of other hurricanes and strong storms that have affected the Bay of Campeche. This information could then be used to develop a statistical estimate of the 100-year storm conditions which are commonly used for design and evaluation purposes. Using data obtained from the special inspections and from the 100-year storm criteria. mathematical models of the pipelines and risers could be prepared and analyses be made to check the stress and stability on each pipeline component.