Land-based Operations Research Articles

Impact of infectious diseases associated with passenger ships on ports: a systematic review

Abstract Background In an enclosed ship environment, close contact between passengers and crew members is inevitable. As a result, passenger ships can be a suitable environment for the transmission of infections between people. In this context, it is essential to establish effective prevention and control measures to protect the health of passengers and crew members while ensuring that shipping minimizes its contribution to the global spread of disease. The aim of this review is to provide knowledge on the impact of infectious diseases on board large passenger ships on the port, the port community and other land-based operations to better understand the effectiveness of the prevention, mitigation and management (PMM) measures implemented, in particular ship-to-shore communication. Methods A systematic literature review was conducted according to the PRISMA guidelines, searching three databases and including additional articles from hand searches up to November 2023. Peer-reviewed studies of infectious disease outbreaks on large passenger ships that described ship-shore interaction, port preparedness, impact on the port community, and impact on other modes of transportation were included. Results A total of 555 publications were initially identified. Finally, 22 articles were included. Most studies reported on COVID-19 outbreaks on cruise ships; other communicable diseases reported were influenza, gastroenteritis and varicella. The articles highlighted the importance of comprehensive management plans and proactive risk assessment during infectious disease outbreaks. Conclusions Effective stakeholder collaboration, ship-to-shore communication, and coordination of medical transport, isolation, and quarantine measures are essential components of infectious disease PMM in maritime passenger shipping and ship-to-shore operations. The findings suggest that further research is needed to improve the evidence and knowledge about this important issue. Key messages • Proactive risk assessment, comprehensive management plans and effective collaboration are critical to preventing, mitigating and managing infectious diseases on passenger ships. • Overall, very little evidence of effective practices and capacities related to the interaction of passenger ships with land-based operations, stakeholders and port communities.

Design & Development of Rescue Assistance Rover for Land-Based Operations

In the face of natural disasters like earthquakes and landslides, timely and efficient rescue operations are paramount to saving lives. However, these operations are often hindered by hazardous conditions and inaccessible terrain. This research focuses on the design and development of a Rescue Assistance Rover (RAR) aimed at enhancing the capabilities of rescuers in challenging environments. The RAR integrates advanced robotics, sensory systems, and communication technologies to navigate through debris, assess hazards, and provide crucial assistance to rescue teams. By leveraging autonomy and remote operation capabilities, the RAR aims to augment human efforts, improving overall response effectiveness and minimizing risks to both rescuers and survivors. This paper outlines the conceptualization, design considerations, development stages, and potential applications of the RAR, highlighting its potential to revolutionize disaster response efforts and save lives in critical situations. Key Words: Additive Manufacturing, 3D Printing, Rocker Bogie Mechanism, Arduino Programming, Rescue Operations, Robotics

A stakeholders’ perception: Turkish aquaculture sector under COVID-19 pandemic effect with consideration of anthropogenic stressors

The Turkish aquaculture sector is growing very rapidly, yet the impacts of the pandemic on both sea and inland water operations remain unclear. To provide a knowledge baseline based on stakeholders, we carried out a rapid assessment in the present study. The primary objectives were to evaluate the stakeholder perceptions regarding economic loss attributed to the COVID-19 pandemic, the effectiveness of implemented mitigating measures, and the overall impact on health and wellbeing. The study also asked respondents about the disruption and loss they felt as a result of the consequences of anthropogenic stresses over the previous ten years. Out of 195 survey participants, only 107 completed and were assessable (73 from land-based farms and 34 from sea-based farms). Ninety percent of those surveyed said they had suffered various levels of financial loss as a result of the COVID-19 epidemic, especially in land-based systems. Loss of market and clients appeared to be a major issue, particularly for land-based farmers. To deal with the problem, sea-based farmers tried to develop integrated aquaculture systems, change farming systems and increase the link with scientists, whereas land-based operations preferred changing marketing methods such as direct sales to consumers, substitute market and processing methods to deal with the problem. The respondents reported higher loss associated with anthropogenic stressors, namely diseases and heat waves. Our results suggest that the decision-makers should be more prepared for such unexpected crises and take anthropogenic stressors into account when designing future recovery strategies for this productive sector.

Supporting shipboard helicopter flight testing with simulation and metrics for predicting pilot workload

Shipboard helicopter operations are much more challenging and complex than land-based operations due to many factors associated with the presence of the ship. To determine those conditions in which safe operations may occur, a First of Class Flight Trial (FOCFT) is conducted for every new ship–helicopter pair. This trial results in a Ship–Helicopter Operating Limit (SHOL) envelope that is used to document operational limits for regular operations. Conducting a FOCFT is a, expensive, and time-consuming task that requires testing all aspects of operations. Modeling and simulation efforts to support shipboard helicopter operations have been ongoing internationally for many years with the intention of de-risking FOCFT and introducing efficiency into the testing process. Canada will be accepting several new ship classes into its fleet over the next two decades. In support of FOCFT for these new ships, modeling and simulation tools are being developed by the National Research Council (NRC) Canada and Defence Research and Development Canada (DRDC) and significant advancements have occurred in the past decade. As part of this work, NRC and DRDC now use a framework and analysis approach that is intended to standardize SHOL testing with the use of modeling and simulation. This paper introduces that framework and gives details on the modeling and simulation tools that can be used to reduce risk and increase efficiency for Canada’s upcoming FOCFTs.

Investigation of the Effect of Ski Jump on the Flow Dynamics around Generic Aircraft Carrier

The landing operation on an aircraft carrier is a complicated and risky process. Unlike land-based operations, the landing area available on carriers is in continuous motion in all the six degrees of freedom. The ski jump, flight deck, hull, and superstructure of the carrier interact with the oncoming wind’s flow-field which creates a turbulent airflow behind the carrier. This ‘burble effect’ is very dangerous and has caused various mishaps in the past. To complement the work being undertaken at IIT Delhi to study the flow dynamics in the carrier environment, the present study investigates the effect of ski jump and superstructure on the flow around the generic aircraft carrier (GAC). Computational fluid dynamics (CFD) studies are undertaken to simulate the airwake and establish a baseline with the ski jump. Subsequently, further studies are carried out to analyse the sensitivity of the wake to changes in carrier geometry. The introduction of the ski generates a major proportion of turbulence encountered in the aft by the approaching pilot. This is reduced significantly by optimising ski jump geometry in various ways.

Help we are sinking! Stories from Norwegian dispatch centers on decision-making in unfamiliar and ambiguous situations.

The aim of this exploratory case study was to examine whether sensemaking processes may influence decision-making of emergency call center dispatchers when dealing with maritime crises. This article focuses on sensemaking and decision-making in an emergency services context using Norwegian operators as a case and reports on data collected from five focus-group interviews with emergency dispatchers at five different locations. Each focus group consisted of three dispatchers, representing the three main Norwegian emergency response dispatch centers: police, fire and rescue, and the Emergency Medical Communication Centre (AMK). The study's purpose was to see whether choices made when responding to maritime crisis calls are influenced by sensemaking processes, and whether these processes may have influenced the dispatcher's choice of which search and rescue resources to contact. The study found that the sensemaking processes that occurred prior to the decision-making might have been influenced by the dispatcher's past experiences, in particular, experiences from land-based operations. The findings also suggested that the emergency dispatchers made decisions based on intuitive sensemaking, as they were perceived pressed on time and experienced maritime crisis in a more transboundary nature than everyday land-based emergencies. The effects of sensemaking processes and intuitive decision-making shown in this study are of possible relevance to emergency services educators and managers outside a Norwegian framework.

The growth of finfish in global open-ocean aquaculture under climate change.

Aquaculture production is projected to expand from land-based operations to the open ocean as demand for seafood grows and competition increases for inputs to land-based aquaculture, such as freshwater and suitable land. In contrast to land-based production, open-ocean aquaculture is constrained by oceanographic factors, such as current speeds and seawater temperature, which are dynamic in time and space, and cannot easily be controlled. As such, the potential for offshore aquaculture to increase seafood production is tied to the physical state of the oceans. We employ a novel spatial model to estimate the potential of open-ocean finfish aquaculture globally, given physical, biological and technological constraints. Finfish growth potential for three common aquaculture species representing different thermal guilds-Atlantic salmon (Salmo salar), gilthead seabream (Sparus aurata) and cobia (Rachycentron canadum)-is compared across species and regions and with climate change, based on outputs of a high-resolution global climate model. Globally, there are ample areas that are physically suitable for fish growth and potential expansion of the nascent aquaculture industry. The effects of climate change are heterogeneous across species and regions, but areas with existing aquaculture industries are likely to see increases in growth rates. In areas where climate change results in reduced growth rates, adaptation measures, such as selective breeding, can probably offset potential production losses.

Integrated GIS and AHP for Marine Aquaculture Site Selection in Penghu Cove in Taiwan

Marine cage culture has been developed quickly in recent years from land-based operation transfer to marine cage culture by government policy in Taiwan. Therefore, the suitable site selection is an important premised and key factor for successful marine cage culture and sustainable development in the future. Especially, it’s greatly influences economic viability by determining capital outlay and affecting running costs, production and mortality. Hence, the decision factors such as climate factors, geographic environmental factors, bio-environmental factors and social-economic factors are more important for site selection. This study use AHP (analytic hierarchy process) to evaluate the criteria weight for site selection. From AHP analysis, the weights of suitability of the four Geographic Information System (GIS) grid themes were 0.322, 0.410, 0.127 and 0.141, respectively. The result shows that the geographic environmental factors are the most important factors in selection suitable marine culture sits in Penghu cove in Taiwan. At the meanwhile, by using ArcMap, a GIS software package, a suitable map was made based on the selected grid themes. The suitable sites for marine cage culture development identified on the individual GIS grid themes, the GIS software and AHP method can be integrated to select objectively the optimal sites for marine cage culture development.

Laboratory-scale evaluation of the potential of chemical containment for farmed abalone larval escapees

The sensitivity of abalone Haliotis midae larvae to low levels of toxicants was used to conduct a laboratoryscale experiment to determine the possibility of using chemical containment to prevent the escape of larvae from land-based culture systems, thereby reducing the environmental impact of farming operations. The cryoprotective agent, dimethyl sulphoxide or DMSO (Me2SO), was used as a toxicant and embryos were exposed to increasing concentrations (0–25.60 mol l–1) of DMSO for a period of 24 hours. Hatch-out rates of the control group (0.0% DMSO) did not differ from those obtained at 0.2% (2.56 mol l–1) and 0.4% (5.12 mol l–1) DMSO. An exposure level at and above 0.6% DMSO resulted in a significant decrease in the number of normal larvae. At an exposure concentration of 0.6% (7.68 mol l–1) DMSO, 65% (SE 3.0) of the fertilised eggs hatched, compared to only 10% (SE 2.0) at a concentration of 1.0% (12.80 mol l–1) DMSO. This study indicates the potential for use of DMSO as a form of chemical containment of abalone larvae, even at very low doses. It presents South African abalone farms with a chemical containment method that could potentially be used to prevent the unintentional escape of H. midae larvae from land-based operations.

Technology Focus: Production Monitoring/Surveillance

Technology Focus As we take a look over the last year, the industry has seen further advancements in the areas of production monitoring, surveillance, analysis, and optimization. We continue to find new ways of data gathering, processing, and interpretation. We are optimizing our operations and even predicting future production behavior in a new manner. Innovative intervention methods have also followed with creative methods of addressing a variety of performance issues. We have become more efficient at using existing technology to improve performance in mature fields and in full-field management strategies for new developments. Technology is improving continuously to help us with production optimization through new approaches, including downhole multiphase-flow measurement, wireless data gathering, wireless power-transfer methods, and new fluids technology. We have seen enhancement in predictive analysis with regard to determination of production performance as well as equipment failure for multiple types of artificial-lift methods. The last year witnessed further studies and improvements in the understanding of heavy-oil and unconventional reservoirs. While production optimization is improving continuously, growing environmental concerns are also being addressed with better understanding and technology. The contributions allowing these steps forward are being generated from large fields, offshore developments, smaller land-based operations, and all sectors of our business. New ideas and methods are being shared from all regions of the globe, demonstrating the diversity and strength of the industry as well as the people making these contributions. This efficiency and innovation should help us continue on a path of success as global markets change in the future. The articles selected for review are intended to show some examples of implementing multiple concepts and methodologies for production evaluation while applying the data to achieve better performance. While demonstrating the full system overview, also included is an insight into the enabling technology allowing these improvements and possibly a glimpse into what may lie ahead as we continue down the path toward further understanding of our reservoirs. JPT Recommended additional reading at OnePetro: www.onepetro.org. SPE 171101 An Integrated Approach Using Commercial Monitoring and Surveillance Tools Coupled With Statistical Analysis Techniques To Optimize Oil, Heavy-Oil, and Extraheavy- Oil Reservoirs by D. Lee, DL Petroleum Engineering and Consulting, et al. SPE 170864 Mature Fractured Reservoir Meets the Era of Young Minds and the New Age of Technology Digital Oil Field by Mariam Abdul-Raheem Jamal, KOC, et al. SPE 164854 Downhole Multiphase-Flow Measurement in Horizontal Wellbores by o. Haldun unalmis, Weatherford, et al.

Numerical Study of Helicopter Rotors in a Ship Airwake

Operating helicopters in a naval environment is challenging because it imposes a pilot workload significantly higher than that during land-based operations. The aerodynamic interaction between the aircraft and the ship wake is known to play an important role in increasing the pilot workload, hence reducing the aircraft capability as a result of maintaining safety. As a further step toward numerical prediction of ship/helicopter operational limitations, computational-fluid-dynamics simulations are conducted for the Canadian Patrol Frigate. The effect of the rotor is included in the simulation, first using an actuator-disc method together with steady calculations, then using rotor blades and the unsteady Reynolds-averaged Navier–Stokes equations. Results using the actuator-disc method demonstrate the importance of coupling effects on the wake and rotor inflow when the rotor is operating close to the ship and therefore the invalidity of superposition methods. The case of a Sea King helicopter main rotor hovering above the deck just before touchdown is reproduced to overcome the limitations of steady calculations and the actuator-disc method. Predictions of rotor thrust compare well with the experimental data available and give confidence in the results. The findings highlight the differences in rotor loading between forward flight and near-deck operation. The possibility of using such simulations for determining safe flight envelopes is discussed as part of the future work.

Somali Piracy: A Form of Economic Terrorism

Piracy over the years has been driven by geography, political instability and the availability of safe havens. Apart from these established factors, economics too play a role. This article reviews and examines Somali piracy, which has flourished due to the international community ignoring the growing instability in Somalia, the rampant illegal fishing and toxic waste dumping. It examines the international response, the legal and economic factors and advocates that piracy be viewed as a form of economic terrorism and be combatted as such, as well as by land-based operations.

Somali Pirates as Agents of Change in International Law-making and Organisation

Somali piracy is a highly adaptive business activity that can only be understood in context. The present article aims to provide an analysis of the phenomenon and in particular its impact on international law-making and organisation. The relevant developments have moved fast enough that there is already a significant history of international co-operation in response to Somali piracy. The contention of this article is that the most important impact of Somali pirates as agents of change has not been on the substantive law of piracy but through generating new models of co-operation and soft-law. This has been evident in a range of shifts: the move from a military approach to law enforcement operations; from unilateral enforcement to international authorisation and then to transnational co-ordination; a shift from reliance on formal organisations to informal co-ordinating bodies; and from maritime operations in the Gulf of Aden to various land-based operations, most notably including law and prison reform. The use of soft-law in particular is most evident in the shipping industry's response to piracy. The present article thus proceeds by first offering an extended account of the history of Somali piracy and its context. This is vital for two reasons: first, one must appreciate that Somali piracy is not a static phenomenon; and second, understanding how Somali piracy is shaped by its context cautions us against concluding that Somali-style piracy may `spread' to other regions. The article then turns to the rise of international counter-piracy operations and counterpiracy co-operation. Here we see a rapid shift from a largely `military paradigm' response (unilateral actions and Security Council authorised missions) to a

Operational Risk Analysis of LNG Loading

This article, written by Assistant Technology Editor Karen Bybee, contains highlights of paper OTC 20982, ’Operational Risk Analysis of LNG Loading,’ by B.H.K. Chin, P. Friis-Hansen, and T.G. Saetren, Det Norske Veritas, originally prepared for the 2010 Offshore Technology Conference, Houston, 3-6 May. The paper has not been peer reviewed. The increased interest in risk analysis is the result of several operators wanting to understand properly their risks in the operational phase, and in this way, through proper preparedness, to avoid or mitigate incidents and major accidents and to improve resilience toward these unwanted events. The full-length paper presents the results of a detailed risk analysis of a liquefied natural-gas (LNG) export loading operation at a jetty. The analysis takes into account the interaction between the vessel crew and the land-based operators. Introduction The objective of operational risk management is to satisfy multiple requirements of multiple stakeholders to control losses from operations. One particular objective of an operational-risk-management system is that it should provide a strong ability to forecast conditions and give input to management before the development of dangerous conditions. A second objective is to approach risk in a holistic way in assessing risk from unwanted losses resulting from loss of life and property and the effects on the environment. This requires a thorough understanding of the technical-systems reliability, of the organizational performance, and of how the interaction between the two affects the total-systems performance. This implies that a practical requirement for risk management of unwanted losses during the operation phase is that the risk modeling should encompass the systemic interactions between technical and human organizations. The solution for systemic risk requires a holistic perspective in hazard identification, risk analysis, and risk mitigation. This may provide the operator with a useful set of risk-based indicators to guide the risk-management process. Case-Study Description The intent of the test case is to model the loading mode at an LNG jetty, identifying potential failure scenarios and determining the risk profile for the loading operation. The main objective is to determine the safety and on-time performance of the loading operation. The investigation examines the possibility of technical failures, the errors caused by individual human performance, the organizational influences on the operation, and the combined factors from interfacing two sets of technical and human organizational systems (i.e., the land-based jetty operation and the ship-based operation). The process of transporting LNG has inherent risks associated with it. The LNG is handled in cryogenic conditions and if released, the vaporized gas can form a flammable or explosive mix with air at a flammable range of 5 to 15% concentration. The LNG carrier is on fixed charter, and the delivery performance is affected directly by the on-time performance of the LNG loading.

Sustainability and Australian Coastal Shipping: Some Issues

This paper raises the issue of coastal shipping as an addition and/or alternative to the environmental unfriendly land-based transport operations. It investigates changing government policies relating to coastal and short sea shipping adopted overseas. It points out that Australia’s freight task is somewhat different with its long coastline, cabotage restrictions and high operating costs which has meant that shipping is now confined primarily to carrying bulk cargoes; ones that cannot be carried by land transport. The paper investigates whether and under what conditions coastal shipping can become an effective transport mode for non-bulk cargoes and raises some issues that must be addressed in order for it become a viable alternative.

Techbits: R&D Conference Examines Hydrocarbon Sustainability

Techbits With global energy demand predicted to grow substantially in the next 30 years, the oil and gas industry will be expected to continue providing the lion's share of future supply. With a theme of "Fueling the Future," the 2009 SPE Research & Development (R&D) Conference investigated the new technologies and energy players required to meet the world's energy needs. Nearly 100 attendees converged on Lisbon, Portugal this year to discuss the R&D disciplines that would ensure hydrocarbons’ role as a major energy source in the coming decades. Major conference themes included: maximizing recoveries from known fields, discovering and exploiting new reserves, unlocking trapped energy molecules, solving water-management challenges, and increasing productivity in a time of manpower and resource shortages. Fueling the Future In the first session, leading scientists and economists framed the challenges that confront the industry in providing sufficient energy supplies for the global economy. John Barry, vice president, Unconventionals and Enhanced Oil Recovery (EOR) for Shell, discussed technology's vital role in extracting more hydrocarbons from increasingly challenging areas, while also keeping costs down and managing CO2 emissions. He estimated that there are nearly 2 trillion barrels of challenging reserves in the form of heavy oil, oil and gas shales, and in Arctic and ultradeepwater regions. Tapping this vast resource will require further investment in offshore satellite developments, power from renewable resources, more smart well completions, and new deepwater and Arctic rig technology. Chief Economist Dave Larson with PFC Energy next reviewed the impact of the global financial crisis on the energy industry. He said that the industry is reeling from a triple blow of collapsing oil price, decline in hydrocarbon demand that may persist for years, and the drying up of new credit availability, all of which will hamper normal business financing and cause some E&P programs to be postponed or cancelled, which has already begun. In the long-term, Larson said that there is no fundamental change to the expected future supply/demand crunch and that this crisis may create growth opportunities, particularly for national oil companies (NOCs). "NOCs with strong balance sheets, solid cash positions, and low debt ratios will be well-positioned to emerge as major global players," he said. Discovering Future Reserves The second session reviewed the new seismic, remote-sensing, and drilling technologies required to discover future reserves from increasingly challenging areas. Gerhard Thonhauser of TDE Thonhauser Data Engineering discussed drilling in extreme environments like desert and Arctic regions, high-pressure and high-temperature reservoirs, and ultradeep geographic targets. He called for an industrywide step-change in drilling efficiency, which can be achieved by developing an ultralight drillstring concept to expand the drilling envelope, drilling more offshore targets from less expensive land-based operations, and by reaching deeper targets with existing rigs. Developmental challenges include material compatibility with hostile downhole environments, hydraulics limitations, and poor wear and torsion resistance.

DEVELOPMENT AND CURRENT STATUS OF ABALONE AQUACULTURE IN CHILE

Abalone aquaculture is rapidly developing in Chile although this mollusc does not occur naturally in this country. The red abalone Haliotis rufescens was introduced in 1977 and the ezo abalone Haliotis discus hannai in 1982. After several years of research and development, the industry began in 1992 and Chile is currently the fifth producer of cultured abalone in the world with 304 tons in 2006. Twenty five companies are involved in this Chilean industry, culturing mainly red abalone. Most of the farms in the North include hatcheries and land-based grow-out operations, whereas most of the in-water grow-out facilities are located in the South. All farms in Chile use algae as the main food for growing abalone, but artificial feeds are also used in some land-based operations in the North. The average size of abalone harvested in Chile is 8 cm (100-120 g) after 3-5 y in culture systems. Whole frozen abalone (shell on) is the most important form of this Chilean product (82% in 2006) and the main market is Japan (90.2%). Abalone production has increased at a rate of around 50% per annum over the last 3 y. This development is expected to continue in the next years, fostered by favorable geographic, economic, and environmental conditions as well as an important government support to invest in abalone. A survey among producers revealed that feed availability and quality is currently considered a key issue to further develop this industry in Chile.

Overview: Wellbore Integrity, Sand Management, and Frac Pack (September 2006)

Geomechanics tools are used to forecast, and then gauge, asset performance over time. Wellbore integrity, sand management, and frac-pack engineering design and execution practices are linked by characterizing the geological section in terms of rock mechanical properties. Often, seemingly unrelated events that can plague high-risk, high-cost developments can be understood best when the geological environment, the geology and geophysics, is described as an engineering material (i.e., the rock mechanical properties that include formation strength and stress). A consistent characterization of formation stress and strength with the geological structure, lithology, and seismic attributes used to recognize the prospect ensures that the explorationists' vision is linked to the well engineers' design. Further, a consistent mechanical-property model for the field can be used to create a full-cycle asset-development plan from appraisal through abandonment, helping to reduce the risk of missed future opportunities resulting from well-systems-design constraints. Two examples come to mind.Reservoir-pressure depletion and subsidence can affect borehole stability to the extent that complex well designs are necessary to exploit the asset fully. Well placement depends on the subsiding reservoir section and on the reaction of the overlying geological section that must be drilled through to reach the reservoir.Sanding-potential risk usually increases with depletion. For compartmentalized reservoirs with varying depletion schedules, sand-risk mitigation often leads to one-size-fits-all completions that usually result in sand control. This method can limit re-entry options and decrease recovery. An accurate forecast of sanding tendencies for individual reservoirs, including the field production-management practices that affect sanding, can result in a more selective fit-for-purpose approach to completion design. For land-based operations, the consequences of well complexity may be addressed more easily; the downside is a poor estimate of field recovery that can either reduce opportunities for outlying prospects or, in the worst case, cause the asset to seem uneconomic. For major-capital projects such as deepwater subsalt fields, the capital outlays are immense, with single wells costing U.S. $100 million. For these deepwater projects, it is required that fewer wells produce reliably for longer periods of time. Well engineers need to get it right the first time. Wellbore Integrity, Sand Management, and Frac Pack additional reading available at the SPE eLibrary: www.spe.org SPE 95715 "Prediction of Sand-Production Rate in Oil and Gas Reservoirs: Field Validation and Practical Use" by P.J. van den Hoek, SPE, Shell Intl. E&P B.V., et al. SPE 98252 "Prediction of Sanding Using Oriented Perforations in a Deviated Well, and Validation in the Field" by I. Palmer, Higgs Technologies, et al. SPE 95514 "Evolution of Frac-Pack Design, Modeling, and Execution in the Ceiba Field, Equatorial Guinea" by C.L. Cipolla, Pinnacle Technologies, et al.

LARGE-BORE GAS WELL DESIGN—APPLICATION TO OFFSHORE GAS FIELD DEVELOPMENT

Offshore gas development projects including the North West Shelf of Australia continue to develop new technologies in order to reduce development costs. Given that the number of development wells directly relates to capital expenditure, past attempts have focussed on obtaining higher gas rates out of conventional well designs by carefully managing erosional limits, which, in turn, tend to restrict the use of higher offtake rates.A strategy based on safely flowing gas wells at higher rates results in fewer wells and delays the phasing-in of additional wells, both of which result in economic enhancement. In recent times the industry has increasingly moved to large-bore gas well technology as a means of realising this strategy. Large-bore gas wells are defined as wells equipped with production tubing and flow control devices larger than 7” or 177 mm. Originally developed for land-based operations, this technology is increasingly moving offshore into totally subsea systems. One factor limiting the speed of adoption of this technology is the trade-off that exists between the increased offtake rates offered by large-bore systems and the risks posed by wear due to erosion in and around the wellhead area caused by any solids entrained in the gas stream.The problem becomes more acute when different-sized well designs employ the same wellhead configurations, because the upper wellhead area is usually the critical and limiting wear component.This paper summarises the recent developments in large-bore offshore applications and presents a consistent methodology showing how different gas well designs can be compared using hydraulic and erosional considerations. Additional trade-offs posed by reliable solids monitoring and the adoption of untested wellhead and intervention designs are discussed. In many cases, hybrid designs based on large diameter tubulars but with conventional wellheads may offer a useful balance between higher well rates and adoption of proven technology. The results shown here are directly applicable to alternative well designs presently under consideration for a number of offshore reservoir developments.

Simple Models Suggest Answers to Complex Questions Do We Need Satellite Surveillance for Land Warfare? A Lancastrian View.

This technical working paper presents a model suggesting that the development of a satellite military system, when once in place, would not be more efficient in terms of required military expenditures of the U.S. than a land-based military operation (system). Hence, if not basically modified to incorporate suggestions for change, the model indicates that the large requirements for development expenditures on a satellite military system would be a clear waste of funds for a technologically superior nation such as U.S. is currently. These funds could be more usefully spent to develop a more effective means to police the global system.