A Methodology to Simulate Floating Offshore Operations Using a Design Wave Theory

2005 ◽  
Vol 128 (4) ◽  
pp. 304-313 ◽  
Author(s):  
Lee O’Neill ◽  
Emmanuel Fakas ◽  
Mark Cassidy
Keyword(s):  
Oil And Gas ◽  
Wave Model ◽  
Wave Theory ◽  
Contact Forces ◽  
Efficient Manner ◽  
North West ◽  
The North ◽  
Large Numbers ◽  
Cost Efficient ◽  
Offshore Operations

Numerical techniques are extensively used to predict vessel motions and associated contact forces for offshore operations such as lift and floatover deck installations. The accuracy of such predictions however is highly dependent on the comprehensive modeling of sea state conditions, which is often limited by computational power and time constraints. A time-efficient methodology, suitable for modeling large numbers of installation sea states, is developed to alleviate this problem. The methodology is based on the Constrained New Wave model which has been previously used to overcome similar problems. However this has only been for individual, extreme storm conditions. The accuracy, time-efficiency, and practicality of the revised methodology is demonstrated by means of direct comparison of simulation results obtained for a floatover deck installation on the North West Shelf of Australia. The ability to perform a large number of simulations in a time and cost efficient manner is of paramount importance in assessing the system limitations to varying installation conditions, a case that has always been challenging to designers during the development of oil and gas projects. Such flexibility improves confidence in the overall system, necessary for the accurate assessment of the commercial viability of marginal developments.

A Novel Application of Constrained NewWave Theory for Floatover Deck Installations

2004 ◽  
Author(s):  
Lee A. O’Neill ◽  
Emmanuel Fakas ◽  
Mark Cassidy
Keyword(s):  
Oil And Gas ◽  
Contact Forces ◽  
Computational Power ◽  
Numerical Techniques ◽  
Efficient Manner ◽  
North West ◽  
The North ◽  
Commercial Viability ◽  
Large Numbers ◽  
Cost Efficient

Numerical techniques are extensively used to predict vessel motions and associated contact forces for offshore operations such as lift and floatover deck installations. The accuracy of such predictions however is highly dependent on the comprehensive modelling of seastate conditions, which is often limited by computational power and time constraints. A time-efficient methodology, suitable for modelling large numbers of installation seastates, is developed to alleviate this problem. The methodology is based on the Constrained NewWave model which has been previously used to overcome similar problems. However this has only been for individual, extreme storm conditions. The accuracy, time-efficiency and practicality of the revised methodology is demonstrated by means of direct comparison of simulation results obtained for a floatover deck installation on the North West Shelf of Australia. The ability to perform large number of simulations in a time and cost efficient manner is of paramount importance in assessing the system limitations to varying installation conditions, a case that has always been challenging to designers during the development of oil and gas projects. Such flexibility improves confidence in the overall system, necessary for the accurate assessment of the commercial viability of marginal developments.

Geothermal condition and outlook for oil and gas deposits in the north-west Black Sea shelf

2002 ◽  
Vol 8 (2-3) ◽  
pp. 206-208
Author(s):  
V.G. Osadchyi ◽  
◽  
O.A. Prykhod'ko ◽  
I.I. Hrytsyk ◽  
◽  
...  
Keyword(s):  
Black Sea ◽  
Oil And Gas ◽  
North West ◽  
The North ◽  
West Black Sea

Field Implementation of RBI for Jacket Structures

2003 ◽  
Author(s):  
Michael H. Faber ◽  
Daniel Straub ◽  
John D. So̸rensen ◽  
Jesper Tychsen
Keyword(s):  
Sensitivity Analysis ◽  
Data Base ◽  
Stress Ratio ◽  
Oil And Gas ◽  
Inspection Planning ◽  
The North ◽  
Large Numbers ◽  
Structural Details ◽  
Jacket Structures ◽  
The North Sea

The present paper first gives a brief outline of the simplified and generic approach to reliability and risk based inspection planning and thereafter sets focus on a recent application of the methodology for planning of in-service NDT inspections of the fixed offshore steel jacket structures in the DUC concession area in the Danish part of the North-Sea. The platforms are operated by Maersk Oil and Gas on behalf of DUC partners A.P. Mo̸ller, Shell and Texaco. The study includes a sensitivity analysis performed for the identification of relevant generic parameters such as the bending to membrane stress ratio, the design fatigue life and the material thickness. Based on the results of the sensitivity analysis a significant number of inspection plans were computed for fixed generic parameters (pre-defined generic plans) and a data-base named iPlan was developed from which inspection plans may be obtained by interpolation between the pre-defined generic plans. The iPlan data-base facilitates the straightforward production of large numbers of inspection plans for structural details subject to fatigue deterioration. In the paper the application of the generic inspection plan database iPlan is finally illustrated on an example.

Achieving Indonesian Oil and Gas production to 1 million barrels per day by 2030 using Nanoflooding as Novel EOR Method: Dream vs. Reality

2021 ◽  
Author(s):  
L. Hendraningrat
Keyword(s):  
Oil Recovery ◽  
Cost Efficiency ◽  
Oil And Gas ◽  
Gas Production ◽  
Oil Price ◽  
Efficient Manner ◽  
Oil And Gas Production ◽  
Cost Efficient ◽  
Nano Size ◽  
Production Target

In low oil price environments, conducting affordable enhanced oil recovery (EOR) projects can be very challenging. One item of interest for successful future EOR should be in how produced fluids are treated and how to achieve cost-efficiency. Nanoflooding, is an emerging EOR technique, which has attracted deployment in recent years. Meanwhile, Indonesia continues to progress towards the national oil and gas production target of one million barrels per day by 2030. This paper presents the observation of opportunities and challenges of using nanoflooding to enable oil and gas production in Indonesia to achieve its desired targets. The study began by mapping the pain points in major oilfields in Indonesia. We observed and discussed the advantage and limitation of traditional mature EOR techniques, status, and ongoing application of EOR in Indonesia. Then, we briefly explained the main reasons why nanoflooding can be considered for future implementation in accelerating oil production in Indonesia, including a discussion about a successful pilot test. As an emerging EOR technique, nanoflooding can be considered as a cost-efficient technique. Silica-based nanofluid can be accessed in a cost-efficient manner and can be executed from an implementation standpoint considering surface facilities. The mechanism that is introduced can help to displace incremental oil more effectively since it can go inside pore throats due to the nano-size. We observed several recognized benefits and challenges to deploy nanoflooding in Indonesia. Based on this study, nanoflooding is very attractive and has potential to be implemented.

The Status of Coccinella septempunctata L. and its Varieties divaricata Oliv. and confusa Wied.

1962 ◽  
Vol 94 (12) ◽  
pp. 1341-1343 ◽  
Author(s):  
V. Sudha Rao
Keyword(s):  
Biological Control ◽  
Coccinella Septempunctata ◽  
Silver Fir ◽  
Eastern Himalayas ◽  
North West ◽  
The North ◽  
Large Numbers ◽  
The Status ◽  
Commonwealth Institute ◽  
Indian Station

A survey was recently undertaken by the author with Dr. V. P. Rao, Entomologist-in-charge, Indian Station, Commonwealth Institute of Biological Control, Bangalore, India, for natural enemies of Adelges spp. attacking silver fir (Abies spp.) and spruce (Picea spp.) in the North-West and Eastern Himalayas. In the course of this survey it was found that the coccinellids Coccinella septem-punctata L., C. septempunctata L. var. divaricata Oliv. and C. septempunctata L. var. confusa Wied, were three of the most common predators of Adelges spp. in both these areas. With a view to sending laboratory-reared material to Canada for trial against Adelges piceae Ratz., which is a serious pest there, large numbers of these Coccinellids were collected in the fir and spruce forests to provide breeding material.

Questions Raised in Excavating the Recent Dead

2016 ◽  
Author(s):  
Sian Anthony
Keyword(s):  
Twentieth Century ◽  
Material Culture ◽  
Working Life ◽  
North West ◽  
The North ◽  
Large Numbers ◽  
Short Period ◽  
Special Circumstances ◽  
Historic Cemetery ◽  
Large Sections

The decision to excavate a modern cemetery in the heart of Copenhagen prompted questions which revealed how the sensitive borderlines surrounding the recent dead are dealt with by archaeologists. When the plans for a new metro line were revealed in Copenhagen, the location of one station within a historic cemetery was controversial. Assistens cemetery is an early example of a landscape, or garden, cemetery (Rugg 1998; Tarlow 2000), designed and ordered according to fashionable contemporary garden principles and aesthetics. It has remained a much-loved place where famous personalities are buried as well as many ordinary citizens of Copenhagen. Although burial within the cemetery has become increasingly rare, it is still in occasional use for new interments and for gardens of remembrance for the burial and disposal of ashes. However, in the 1980s changing municipal plans for the cemetery re-designated large sections of it as a park, as described in Helweg and Linnée Nielsen (2010). This change of status enabled the Copenhagen metro company (Metroselskabet) to consider the placement of a station in one corner of the cemetery. Excavation of this site from 2009 to 2011 resulted in the archaeological recording of the material culture of the cemetery including around one thousand burials, their grave-pits, funerary material culture, and some aspects of the working life of the cemetery (Anthony et al. 2016). Assistens cemetery was originally created in 1760 and later expanded in 1805/6. The excavation focused on the north-west corner of the 1805/6 extension, an area surrounding a cemetery administration building (graverbolig). The area was filled by the mid-nineteenth century and continued to be used intensively for the next hundred years. In the latter part of the twentieth century, coffin burial became less frequent but continued until the 1980s. The occasional placement of cremation urns began in the early twentieth century and continued in large numbers into the 1990s (Helweg and Linnée Nielsen 2010). Burial is now uncommon in the entire cemetery and only takes place in special circumstances. In contrast to UK cemetery regulations, Danish law allows for graves to be removed after only twenty years, so there is the possibility of reusing grave plots after this short period by removing the previous coffins.

scholarly journals Four Departmental Asylums in the North-West of France

1874 ◽  
Vol 19 (88) ◽  
pp. 541-552
Author(s):  
J. Wilkie Burman
Keyword(s):  
Small Town ◽  
Great Majority ◽  
Waste Paper ◽  
Maintenance Rate ◽  
North West ◽  
The North ◽  
Walking Tour ◽  
Large Numbers ◽  
Close Proximity ◽  
Lunatic Asylums

In the course of a walking tour, during last summer, I visited, en route, four of the Departmental Lunatic Asylums in the North-West of France, principally with a view to see how they would stand comparison with our own Provincial or County Asylums. Such a comparison, however, could scarcely, I find, be made on a fair basis; for though, undoubtedly, the great majority of the patients in the French Departmental Asylums are paupers, and maintained at the expense of the several Departments, yet, in all, there are associated with these paupers large numbers of pensionnaires, who are maintained by theirfriends and divided into four or five classes, and treated according to their rate of payment. It is obvious, moreover, that the better general and special arrangements, due to and supported by the higher rates of payment of the pensionnaires, would prevent such associated asylums as these from being fairly compared, as to their tout ensemble, with our own County Asylums—in which, as a rule, the patients are all paupers, and chargeable to the different unions, and in which the arrangements are for paupers only, and so constituted as to keep the maintenance rate as low as is compatible with efficiency. Seeing, then, that it was impossible to institute any fair general comparison between the French Departmental Asylums, which I lately visited, and our own County Asylums, I determined, whilst not failing to pay all due regard to the arrangements for, and treatment of, the pensionnaires, to pay more particular attention to the condition and treatment of the pauper patients in the Asylums visited, and to take my notes accordingly. These rough notes, instead of consigning them to the waste paper basket, as has been the fate of former notes of visits made by me to Continental Asylums, I have, this time, determined to offer to my professional brethren, in the hope that they may afford, perhaps, some few crumbs of information and of interest. It will be necessary for me, however, before going further, to state—that, as the principal object of my tour was walking and not mad-house hunting, I did not follow out any predetermined plan as to which particular asylums I should visit. Indeed, it was not until I had well started on my tour that I conceived the laudable idea of endeavouring to combine a little instruction with my amusement, and the result was that I merely visited those asylums which were in close proximity to the route which I had arranged for myself previous to starting. The asylums to which I paid these hap-hazard visits, then, were the following:—1st, “L'Asile de Lehon,” Dinan; 2nd, “L'Asile St. Athanase,” Quimper; 3rd, “L'Asile St. Méen,” Rennes; and 4, “L'Asile de Pontorson,” situated in the small town of that name; and I shall record my notes of them, seriatim, in the order in which they were visited.

scholarly journals Four Departmental Asylums in the North-West of France

1874 ◽  
Vol 19 (88) ◽  
pp. 541-552
Author(s):  
J. Wilkie Burman
Keyword(s):  
Small Town ◽  
Great Majority ◽  
Waste Paper ◽  
Maintenance Rate ◽  
North West ◽  
The North ◽  
Walking Tour ◽  
Large Numbers ◽  
Close Proximity ◽  
Lunatic Asylums

In the course of a walking tour, during last summer, I visited, en route, four of the Departmental Lunatic Asylums in the North-West of France, principally with a view to see how they would stand comparison with our own Provincial or County Asylums. Such a comparison, however, could scarcely, I find, be made on a fair basis; for though, undoubtedly, the great majority of the patients in the French Departmental Asylums are paupers, and maintained at the expense of the several Departments, yet, in all, there are associated with these paupers large numbers of pensionnaires, who are maintained by theirfriends and divided into four or five classes, and treated according to their rate of payment. It is obvious, moreover, that the better general and special arrangements, due to and supported by the higher rates of payment of the pensionnaires, would prevent such associated asylums as these from being fairly compared, as to their tout ensemble, with our own County Asylums—in which, as a rule, the patients are all paupers, and chargeable to the different unions, and in which the arrangements are for paupers only, and so constituted as to keep the maintenance rate as low as is compatible with efficiency. Seeing, then, that it was impossible to institute any fair general comparison between the French Departmental Asylums, which I lately visited, and our own County Asylums, I determined, whilst not failing to pay all due regard to the arrangements for, and treatment of, the pensionnaires, to pay more particular attention to the condition and treatment of the pauper patients in the Asylums visited, and to take my notes accordingly. These rough notes, instead of consigning them to the waste paper basket, as has been the fate of former notes of visits made by me to Continental Asylums, I have, this time, determined to offer to my professional brethren, in the hope that they may afford, perhaps, some few crumbs of information and of interest. It will be necessary for me, however, before going further, to state—that, as the principal object of my tour was walking and not mad-house hunting, I did not follow out any predetermined plan as to which particular asylums I should visit. Indeed, it was not until I had well started on my tour that I conceived the laudable idea of endeavouring to combine a little instruction with my amusement, and the result was that I merely visited those asylums which were in close proximity to the route which I had arranged for myself previous to starting. The asylums to which I paid these hap-hazard visits, then, were the following:—1st, “L'Asile de Lehon,” Dinan; 2nd, “L'Asile St. Athanase,” Quimper; 3rd, “L'Asile St. Méen,” Rennes; and 4, “L'Asile de Pontorson,” situated in the small town of that name; and I shall record my notes of them, seriatim, in the order in which they were visited.

Pioneering Li-ion batteries on an offshore platform

2018 ◽  
Vol 58 (2) ◽  
pp. 719
Author(s):  
Lourens Jacobs ◽  
Nancy Nguyen ◽  
Ryan Beccarelli
Keyword(s):  
Power Generation ◽  
Gas Turbine ◽  
Oil And Gas ◽  
Generation System ◽  
Spinning Reserve ◽  
Fuel Gas ◽  
North West ◽  
The North ◽  
Li Ion ◽  
Power Generation System

Woodside is an Australian oil and gas company and a leading global operator of offshore gas platforms and onshore LNG processing facilities. It is a public company listed on the Australian Securities Exchange headquartered in Perth, Western Australia. Woodside operates the Goodwyn A gas platform on behalf of the North West Shelf (NWS) Project. Woodside assessed Li-ion battery technology and considered the technology mature and ready to be utilised on offshore and onshore operating assets. Woodside operates dedicated islanded gas turbine power generation at each of its onshore and offshore facilities. It was concluded that a large battery energy storage solution (BESS) can deliver several advantages if connected to such an islanded power generation system. The most significant benefit materialises by using a BESS as backup (or spinning reserve) for the gas turbine generators (GTGs). Woodside decided to pioneer the Li-ion BESS technology in a first of its kind application on the NWS Project offshore Goodwyn A gas platform. The Goodwyn A BESS is designed for a 1 MW power and 1 MWh energy capacity, which is considered sufficient to provide the spinning reserve for the Goodwyn A platform. Currently, Goodwyn A operates four 3.2 MW GTGs to provide a typical load of 7–8 MW, with one GTG providing the N+1 spinning reserve. When the BESS is connected to the power generation system, Goodwyn A will operate three GTGs, with the BESS proving the backup in case one of the GTGs trip. The BESS will provide the full 1 MW for a minimum of 1 h, which will give the operators enough time to start the standby GTG or adjust the facility loads (load shedding). The result will be a decrease in overall fuel gas consumption (due to better efficiencies on the remaining GTGs in operation) and a related reduction in CO2 emissions. The project supports the overall objective of the North West Shelf Project to improve the energy intensity of its facilities by 5% by 2020. Woodside believes that developing capability and experience on the installation of BESSs, using Goodwyn A as an early adopter, will facilitate similar and larger installations on other Woodside operated offshore and onshore assets. This is one of the technologies Woodside believes will play an important role to ensure a lower carbon future globally.

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