TX 75083-3836, U.S.A., fax 01-972-952-9435. AbstractNatural gas supply shortfalls are forecasted for the next decade in the U.S. and certain other markets worldwide. Most ongoing efforts to address these shortfalls, such as LNG enhancements and the transition of GTL science from the laboratory to the field, require low gas prices and huge volumes to generate adequate economic returns, and thus have necessitated the targeting of large and remote sources.The marine transport of compressed natural gas (CNG) represents a different approach to the delivery challenge, and recent breakthroughs in technology are providing CNG with the ability to cost effectively ship much larger volumes of gas over greater distances. Thus, CNG is expected to help economically access moderately sized resources (typically 1-5 Tcf) with greater scalability and flexibility while lowering overall capital requirements. Adding to CNG's attractiveness are the modest fixed infrastructure investments needed at the production and market delivery points, and a high degree of security through the use of offshore loading and offloading operations.
Summary Design and operational considerations have been examined in determining the significance of unsupported offshore pipeline spans that may develop during pipeline installation or field operation. Allowable unsupported span lengths determined during design are generally based on strict code compliance and a design foundation encompassing the worst possible environmental and operational loads. During operation, however, possible environmental and operational loads. During operation, however, unsupported spans develop beyond the allowable limits, perhaps as a result of various unforeseen local conditions. Applying original design criteria is likely to result in cost-prohibitive repair predictions, while lack of action may result in loss of production. Without the design code requirements of an existing or a proposed pipeline system being violate realistically safe design can be approached through evaluation of the sensitivity of the key design parameters. Priorities for remedial repair of the unsupported spans can be established for the pipelines in service while operating constraints, budget, and schedule are recognized. On the basis of periodic surveys, properly formatted survey data, and reanalysis of the design parameters, pipeline span repair cost estimates and schedules can be appreciably reduced. Similar principles can be applied to a pipeline in planning and design stages to ensure a safe operating design pipeline in planning and design stages to ensure a safe operating design and to eliminate an uneconomically conservative design. These design and operational considerations are illustrated through a case study. Introduction The design of an offshore pipeline must consider the effect of static and dynamic loads on free span and the risk of free-span failure resulting from the fatigue caused by the vortex-shedding phenomenon. After a successful design effort, pipeline free spans may phenomenon. After a successful design effort, pipeline free spans may develop during pipeline installation and testing or at any time during operation. Operators are often faced with a situation that requires partial or total remedial action to alleviate the problem of free partial or total remedial action to alleviate the problem of free spanning of an unburied offshore pipeline. Time and budget constraints limit remedial field activities once the pipeline is in operation. Therefore, what are the design and operational factors that should be considered in minimizing or avoiding free spans in an unburied offshore pipeline? This paper discusses the effect of unsupported offshore pipeline spans, the factors to he considered during design and operation, and a review of the work published recently. The sensitivity of design parameters that enter into the assessment of the fatigue life and equivalently the allowable unsupported span is examined. The operational considerations include remedial action, preventive maintenance, and planned inspection of the pipeline during operation view of budget and time constraints. The case study discusses recent engineering and repair activities in the offshore pipeline system of the Dubai Petroleum Co.
This paper introduces the marine gas transport technology under development by EnerSea Transport LLC as it is being incorporated in a new ship concept. The new Compressed Natural Gas (CNG) transport system and ship design have global applicability and allow a new perspective on remote offshore oil and gas development. The paper explains how key considerations and challenges have been reflected in the design of the new ship and how that new gas ship concept opens a new world of maritime and offshore field development opportunities. Introduction Industry is beginning to recognize that technology allowing marine transport of Compressed Natural Gas (CNG) provides flexibility that changes the economics for marginal fields. This is especially true for gas fields in ultra-deep waters or locations remote from suitable markets. A new solution for handling, storing, and transporting gas is making many operators appreciate the breakthrough potential for marine CNG as a means to commercialize stranded gas in remote reservoirs around the world. A new class of ocean-going vessels and gas handling facilities will play key roles. Through its Maritime Work Program, EnerSea Transport LLC and its strategic partners have developed an advanced ship design employing the proprietary Volume Optimized TRANsport and Storage (VOTRANS?) gas handling concepts. EnerSea Transport selected the world's leading maritime companies and a top energy company to form a team of unmatched engineering and project development capabilities. The leadership of EnerSea's team includes Kawasaki Kisen Kaisha, Ltd ("K"-Line) and Hyundai Heavy Industries (HHI) with strong professional support from Paragon Engineering Services Inc., the naval architects of Alan C. McClure Associates Inc., and ABS Consulting. This team has worked together with the American Bureau of Shipping (ABS) over the past year to create and verify a safe, practical ship design that provides the basis for launching the world's first fleet for CNG marine transport, opening the way for a new maritime energy transport industry. CNG marine transport allows emerging, energy-hungry markets around the globe to access gas reserves that would otherwise remain stranded. As compared to other solutions for de-stranding of gas reserves (LNG & GTL technologies), the shipping of CNG offers a solution that significantly limits the wastage of gas resources that are needed in the emerging markets and the amount of captive investment required of operators. Such value-adding features make this breakthrough technology and the new class of ships attractive to gas and power players on a global scale.
Desfgn and operational considerations have been examined in determining the significance of unsupported offshore pipeline spans that may develop during pipeline installation or during field operation, Allowable unsupported span lengths determined during the design phase are generally based on the strict code compliance and the design baais encompassing the worst possibilities of the environmental and operational loads. During operation unsupported spans, however, do develop beyond the allowable limits, perhaps due to various unforeseen local conditions. Applying original design criteria is likely to result in cost prohibitive repair predictions, while lack of action may result in loss of production or other concerns.Without violating the design code requirements of an existing or a proposed pipeline system, realistically safe design can be approached by evaluating the sensitivity of the key design parameters.Remedial repair priorities of the unsupported spans can be established for the pipelines in service while recognizing operating constrains, budget and schedule. Based on periodic survey, properly formatted data of the survey and reanalysis of the design parameters, pipeline span repair cost estimates and schedule can be appreciably reduced.Similar principles can be applied to a pipeline in planning and design stages in order to ensure a safe operating design and to eliminate an uneconomically conservative design. These design and operational considerations are illustrated through a case study of work recently carried out.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.