Lena Guyed Tower Decommissioning Engineering

2021 ◽  
Author(s):  
Fu Wu ◽  
Carlos Alvarez ◽  
Gary Osterman ◽  
Ching-Hsiang Chen ◽  
Richard W. Litton ◽  
...  
Keyword(s):  
Artificial Reef ◽  
Analytical Techniques ◽  
Lessons Learned ◽  
Environmental Study ◽  
Environmental Benefit ◽  
Testing Procedures ◽  
Risk Scenarios ◽  
Driving Mechanisms ◽  
Engineering Study ◽  
Offshore Field

Abstract The Mississippi Canyon 280-A platform, also known as Lena Guyed Tower located in 1,000 ft water depth in the Gulf of Mexico (GoM), was successfully decommissioned and reefed in-place in 2020. To meet the regulatory requirements on offshore platform decommissioning, i.e. BSEE decommissioning requirements and the LDWF artificial reef program, an environmental study and an engineering study were performed to ensure that the platform decommissioning satisfies these critical requirements on environmental protection and operational safety. The environmental study revealed the abundance of marine lives residing on the tower and rare coral species only observed in deepwater region. This justified the environmental benefit of turning the tower into an on-site artificial reef and functioning as a vibrant marine life habitat at the end of its production service life. The engineering study on Lena decommissioning, as addressed in this paper, involved three (3) stages of engineering work: tower decommissioning concepts and feasibility study; selected concept definition; and detailed tower reef-in-place laydown (toppling) plan and design. High-level tower reef-in-place criteria were set up in the early engineering stage as guidelines to the detailed laydown design, including specific project requirements on minimal environmental impact and safe offshore field operations. This engineering study relied heavily on multiple expert brainstorm sessions on various decommissioning concepts and options, and advanced structural modeling and computer simulations for assessment and design. A large number of tower structural models were developed to verify the plan and check various factors and risk scenarios that may affect the tower performance in different stages of the decommissioning operation. Advanced analytical techniques were developed and applied, which feature the driving mechanisms of the problem such as soil-structure-interaction, guyline tension, structural member contact and sliding, large displacement simulation, structural collapse, and hydrodynamics. Stringent quality assurance and testing procedures were followed to ensure the credibility of developed analytical techniques and engineering technologies. The most challenging part that differentiates the decommissioning engineering from typical structural design is how to properly estimate the platform in-situ "as-is" condition and carry out the assessment as such to make a regulatory compliant, feasible, reliable, and efficient plan. Therefore, engineering judgment had to go beyond the scope covered by existing industry codes and standards, and rely on the most recent advances in industry research and technology. This engineering study resulted in a clearly defined tower decommissioning plan and procedure, backed up with contingency plans for various risk scenarios and potential deviations in field operation due to limitations and/or uncertainties. The decommissioning plan minimized the offshore field construction scope and risk, and kept the required tower laydown pull loads within the capacity range of typical GoM offshore tugboats. As a result, the Lena tower was successfully laid down on seafloor in an anticipated reefing position, with no major deviations from the plan. Lena Guyed Tower is the first deepwater compliant structure decommissioned. This decommissioning effort may provide the most valuable information and lessons learned to the industry for similar decommissioning and abandonment operations in the future.

scholarly journals School-university partnerships: Lessons learned from 10 years of spectroscopy for teachers and post 16 students

2016 ◽  
pp. 72-76
Author(s):  
TG Harrison ◽  
AJ Shaw ◽  
KL Shallcross ◽  
SJ Williams ◽  
DE Shallcross
Keyword(s):  
Analytical Techniques ◽  
Lessons Learned ◽  
University Partnerships ◽  
Chemistry Students ◽  
Advantages And Disadvantages ◽  
Wide Range

Spectroscopy covers a wide range of analytical techniques, a small sub-set of which UK pre-university chemistry students are required to study. The expense of such equipment means that it is not available to the vast majority of schools whilst it is commonplace in university chemistry departments. This article discusses the evolution of the Bristol ChemLabS spectroscopy outreach activities. The advantages and disadvantages of this method of engagement for both the participants and the providers are discussed from 10 years of activity.

scholarly journals Concerns of Organic Contamination for Sample Return Space Missions

2020 ◽  
Vol 216 (4) ◽  
Author(s):  
Queenie Hoi Shan Chan ◽  
Rhonda Stroud ◽  
Zita Martins ◽  
Hikaru Yabuta
Keyword(s):  
Organic Matter ◽  
Solar System ◽  
Analytical Techniques ◽  
Lessons Learned ◽  
Organic Analysis ◽  
Terrestrial Organic Matter ◽  
Organic Contamination ◽  
Sample Return ◽  
Contamination Control ◽  
Solar System Exploration

Abstract Analysis of organic matter has been one of the major motivations behind solar system exploration missions. It addresses questions related to the organic inventory of our solar system and its implication for the origin of life on Earth. Sample return missions aim at returning scientifically valuable samples from target celestial bodies to Earth. By analysing the samples with the use of state-of-the-art analytical techniques in laboratories here on Earth, researchers can address extremely complicated aspects of extra-terrestrial organic matter. This level of detailed sample characterisation provides the range and depth in organic analysis that are restricted in spacecraft-based exploration missions, due to the limitations of the on-board in-situ instrumentation capabilities. So far, there are four completed and in-process sample return missions with an explicit mandate to collect organic matter: Stardust and OSIRIS-REx missions of NASA, and Hayabusa and Hayabusa2 missions of JAXA. Regardless of the target body, all sample return missions dedicate to minimise terrestrial organic contamination of the returned samples, by applying various degrees or strategies of organic contamination mitigation methods. Despite the dedicated efforts in the design and execution of contamination control, it is impossible to completely eliminate sources of organic contamination. This paper aims at providing an overview of the successes and lessons learned with regards to the identification of indigenous organic matter of the returned samples vs terrestrial contamination.

Oil Spill Monitoring Handbook

2016 ◽  
Keyword(s):  
Oil Spill ◽  
Oil Spills ◽  
Lessons Learned ◽  
Type I ◽  
Environmental Benefit ◽  
Effective Response ◽  
Marine Habitats ◽  
Adverse Weather ◽  
Response Phase ◽  
Oil Exposure

Oil spills can be difficult to manage, with reporting frequently delayed. Too often, by the time responders arrive at the scene, the slick has moved, dissolved, dispersed or sunk. This Oil Spill Monitoring Handbook provides practical advice on what information is likely required following the accidental release of oil or other petroleum-based products into the marine environment. The book focuses on response phase monitoring for maritime spills, otherwise known as Type I or operational monitoring. Response phase monitoring tries to address the questions – what? where? when? how? how much? – that assist responders to find, track, predict and clean up spills, and to assess their efforts. Oil spills often occur in remote, sensitive and logistically difficult locations, often in adverse weather, and the oil can change character and location over time. An effective response requires robust information provided by monitoring, observation, sampling and science. The Oil Spill Monitoring Handbook completely updates the Australian Maritime Safety Authority’s 2003 edition of the same name, taking into account the latest scientific advances in physical, chemical and biological monitoring, many of which have evolved as a consequence of major oil spill disasters in the last decade. It includes sections on the chemical properties of oil, the toxicological impacts of oil exposure, and the impacts of oil exposure on different marine habitats with relevance to Australia and elsewhere. An overview is provided on how monitoring integrates with the oil spill response process, the response organisation, the use of decision-support tools such as net environmental benefit analysis, and some of the most commonly used response technologies. Throughout the text, examples are given of lessons learned from previous oil spill incidents and responses, both local and international. General guidance of spill monitoring approaches and technologies is augmented with in-depth discussion on both response phase and post-response phase monitoring design and delivery. Finally, a set of appendices delivers detailed standard operating procedures for practical observation, sample and data collection. The Oil Spill Monitoring Handbook is essential reading for scientists within the oil industry and environmental and government agencies; individuals with responder roles in industry and government; environmental and ecological monitoring agencies and consultants; and members of the maritime sector in Australia and abroad, including officers in ports, shipping and terminals.

Reservoir Management Challenges of the Terra Nova Offshore Field: Lessons Learned After 5 Years of Production

2007 ◽  
Author(s):  
Einar Dagfinn Haugen ◽  
James Patrick Costello ◽  
Larry B. Wilcox ◽  
Eric Albrechtsons ◽  
Irene Kelly
Keyword(s):  
Reservoir Management ◽  
Lessons Learned ◽  
Terra Nova ◽  
Offshore Field

Clinical Laboratory Biosafety Gaps: Lessons Learned from Past Outbreaks Reveal a Path to a Safer Future

2021 ◽  
Author(s):  
Nancy E. Cornish ◽  
Nancy L. Anderson ◽  
Diego G. Arambula ◽  
Matthew J. Arduino ◽  
Andrew Bryan ◽  
...  
Keyword(s):  
Public Health ◽  
Patient Care ◽  
Laboratory Testing ◽  
Clinical Laboratory ◽  
Lessons Learned ◽  
Infectious Agents ◽  
Testing Procedures

Patient care and public health require timely, reliable laboratory testing. However, clinical laboratory professionals rarely know whether patient specimens contain infectious agents, making ensuring biosafety while performing testing procedures challenging.

Lessons Learned From Tubing Leaks in ESP Completion at Offshore Field

2020 ◽  
Author(s):  
Abdullah M. Al-Dhafeeri ◽  
Saad A. Al-Sdeiri ◽  
Shebl Fouad Abo Zkery ◽  
Hyrliyan Ade
Keyword(s):  
Lessons Learned ◽  
Offshore Field
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