bluuebunny/crossref_metadata_2025_split huggingface dataset:
Challenges in Riser Design - The Ichthys Gas Field Development
Authors: Coone Niall 
Published: March 2016

Abstract
The Ichthys Gas Field is located 220 kilometers offshore from the North West coast of Western Australia. The field is located within a cyclone-prone region and has two permanently moored floating production units in a water depth of approximately 250m.
The floating systems consist of a semi-submersible Central Processing Facility (CPF) and a Floating Production Storage and Offloading (FPSO) facility. This paper presents an overview of the riser solutions developed for each facility while documenting challenges faced in design, cognisant of installation limitations and complex interface management within a large EPCI project. Both facility riser systems contain aspects that are first of their kind within the region and were developed with the added complexity of a 40-year riser design life and the requirement to withstand a 10,000 year return period survival cyclonic event.
Within a single mooring sector to the North of the CPF, 25 risers are supported on a single riser support structure (RSS) in a fixed-S configuration. The RSS, which is the subject of another paper [1], has an arch length of 130 m to support the risers at a height of 110 m above the seabed. This paper explains the design aspects of the system including optimizing riser spacing and riser gutter geometry in close proximity with varying minimum bending radii. A robust design was required that allowed for future phase riser installation and riser replacement.
A lazy-S riser configuration was developed to support 15 risers from the FPSO. The solution consisted of three mid depth buoys (MDBs), one in each mooring sector. The MDB design is the subject of another paper [2]. Design challenges included significant dynamic response of the permanently moored FPSO in 10,000 year return period survival cyclonic conditions. MDB dynamic response was found to be significantly impacted by added mass, which provided challenges in maintaining positive tether tension and minimizing interface loads into the MDB structure and foundation. Diffraction analysis of the MDB structure was used to determine accurately the added mass coefficient in order to refine interface loads into the MDB and its foundation.
Improving Jack-Up Rig Spudcan Penetration Predictions in Malaysian Waters
Authors: Rohani M. J. , Sha'ari F. A. , Rahman A. A. , Ismail W. M. Wan , Chan N. , Tho K. K. 
Published: March 2016

Abstract
A review of the performance of jack-up rig spudcan penetration predictions in Malaysian Waters over the past ten years is performed with the aim of improving the predictions for future deployments. This work is part of an ongoing initiative to further improve the safety and efficiency of jack-up rig deployments in Malaysian Waters.
During the first phase of the study, field measured spudcan penetrations at maximum preload from 100 jack-up rig emplacements in different subsoil conditions are compared against the corresponding spudcan penetration predictions. These spudcan penetration predictions, which originated from third parties and are presented anonymously, consist entirely of Class-A predictions made prior to the jack-up emplacement. A significant scatter is noted between predicted and actual spudcan penetrations. Possible causes of discrepancy between predicted and actual spudcan penetration depths in Malaysian Waters are postulated.
In a significant proportion of the cases reviewed, the final spudcan penetration is found to be governed by bearing capacity in clay. Consequently, bearing capacity solutions for clays detailed in SNAME (2008) and ISO (2012) were reviewed. The bearing capacity equations in SNAME (2008) and ISO (2012) are based on the work of Hansen (1970) and Skempton (1951) respectively. Both SNAME (2008) and ISO (2012) noted that the value of undrained cohesive shear strength can be taken as the average value over a distance of B/2 from beneath the level where the maximum spudcan diameter is in contact with soil. The undrained shear strength profiles in Malaysian Waters are found to be more irregular as compared to those encountered in Gulf of Mexico. It is therefore the objective of the current study to assess the influence of undrained shear strength averaging distance for soil condition encountered in oil and gas producing regions offshore Malaysian Waters and to recommend the most applicable value for use in Malaysian Waters.
The next phase of the study also aims to evaluate the need for revised calibration factors to SNAME (2008) / ISO (2012) based equations and to define the tolerance for acceptance of the leg penetration analysis (LPA) predictions in Malaysia Waters.
A Well Testing Analysis Methodology and Application for Tight Reservoirs
Authors: Zhao Xiaoliang , Liao Xinwei , Chen Zhiming , Mu Lingyu , Zhang Fengyuan , Zhou Yejun , Zhou Xingze , Zhao Ning 
Published: March 2016

Abstract
For tight oil reservoirs, because of ultra-low permeability, the radial flow is difficult to be obtained in pressure build-up testing which results in multi-solution of flow model and interpretation results. How to determine the right model and identify the right interpretation result are the key questions. This paper presents a well test interpretation methodology based on time and space scales to increase accuracy of well-test interpretation results. Two steps are performed to determine reasonable flow model and interpretation results based on time and space scales. For the time scales, the history of well testing data for a single well are interpreted and the interpretation results are compared first. Then for space scales, the well test data in space for multi-wells are analyzed. At this stage, the interpretation results of adjacent wells are compared. The reservoir geological data and the production history are used as a reference to appraise the well test interpretation results. After these two steps, the reasonable interpretation model and interpretation results can be determined. Two cases selected from Changqing oilfields whose permeabilities are almost under 0.5mD and fluid flow rates are very low are analyzed and the great application effect is attained. This methodology is applied in Changqing oilfields extensively and is proved to be a great methodology in ultra-low permeability oil reservoirs. It can be expanded to other unconventional reservoirs, such as tight gas, shale gas and so on. The innovation is that this paper derives a well testing analysis methodology to determine right model and identify the right interpretation result based on time and space scales. It can decrease the errors which are caused by multi-solution of flow model and many interpretation results.
First Meta-Sedimentary Basement Reservoir Formation Evaluation in Offshore Sarawak: A Detail Insight on Fracture Morphology
Authors: Ming Wu Ivan Zhia , Parashar Sarvagya , Lee Chung Yee , Kamarul Zaman M. Naquib , Amri M. Bukhari M. Khairul , Jabbar Siti Fatimah , Lowrans Calvin , Mansur Hussen 
Published: March 2016

Abstract
Exploration and production companies in the South China Sea region have focused increasing attention on basement reservoirs. In the current study, a modest step was to taken to identify the fracture pattern and its associated physical properties, which help provide the potential zone of the formation sampling and pressure gradient analysis. An exploratory well located offshore Sarawak, Malaysia recently encountered oil in the meta-sediment basement—confirming the basement plays in this region.
Borehole microresistivity images and acoustic data with background geology characterized rock texture, lithofacies, and fracture network. Integration of sidewall core and microresistivity image data characterized litho-units having complex architecture. Open fracture zones were validated in images and acoustic logs. Borehole image-derived fracture properties calibrated with sonic-derived results were used to estimate gross voidage. Average porosity in fractured basement rock is usually low; hence, fracture transitivity/permeability is important for estimating fluid movement. To characterize basement rock, fractural properties and geometry, such as permeability, aperture, density, and flow potential, should be attributed properly with respect to the different facies association present.
The exploratory well was mainly drilled through the quartzite and phyllite section. Microresistivity image data helped decipher the different texture patterns with the two litho-units and also identify the internal structural features associated with each. The major types of structural features were identified, including partial fracture, open fracture, and closed fracture. Statistical analysis showed the major strike orientation for the open fracture was toward the NW-SE; whereas, the minor trend was NNE-SSW with a mean dip of 45° magnitude. Partial fractures also exhibited a similar trend, with the major strike NNE-SSW and minor trend NW-SE with mean dips of 52° magnitude. Average open fracture aperture was determined to be in the range of 0.2 to 0.4 mm, with an approximate secondary porosity range between 2 to 3% and permeability of 0.01 md.
This was the first integrated approach for evaluating a meta-sediments basement in the offshore Sarawak area. This methodology emphasized advanced integration and is essential for evaluating such complex reservoirs, providing a stepping stone for future well trajectory planning in the study area.
Proper Planning Supported by Latest Technology Leads to Drilling the Longest 8.5-in. Section in an Extended-Reach Well: Case Study
Authors: Chima Jude , Umarin Isa , Kunhiveetil Dhanraj , Otaif Hassan , Al Dabyah Ali , Zubairi Bilal 
Published: March 2016

Abstract
Over the past years, extended-reach drilling (ERD) field development has significantly increased globally, and its benefits are well recognized. ERD techniques are increasingly used to intersect hydrocarbon targets that are difficult to access due to logistic issues. While these wells are challenging to drill, complete, and service, the benefits can be wide ranging. These benefits drive the development of technology and techniques to continuously expand the ERD envelope and increase the complexity of profiles to reach more challenging targets. The directional drilling and evaluation service supplier plays an important role.
Each ERD well has a unique set of challenges. Common to all ERD projects is that many aspects of drilling engineering principles are not only pushed to the limit, but become highly interrelated and sensitive to smaller changes than conventional wells. For this reason, a team approach to planning and executing ERD activities should be considered critical. Each team member should bring to the project relevant experience, knowledge, a range of field-proven technology, and a solid global support structure.
Drilling successful ERD wells in challenging conditions depends on various factors, which include careful planning and use of the latest technology. Planning involves understanding the geological structure, not only within the reservoir section, but also in the overburden where typically most of the time efficiency gains can be achieved. The last step in planning is designing an efficient bottomhole assembly (BHA) based on previous experiences, lessons learned and inputs from various teams. Good planning is supported by use of new technologies, especially tools that give real-time information, enabling quick and informed decisions to ensure safe and efficient drilling in a challenging environment. The paper discusses the planning and decision-making process to drill ERD wells by using latest real-time technologies in drilling challenging wells. This paper will describe the experiences and huge success of drilling the longest 8.5-in. hole section in an ERD well, drilled and cased smoothly through challenging formations.
Influence of Improved Soil Layer with Deep Mixing Method on the Penetration Performance of Spudcan Foundations in Multilayer Clays
Authors: Won Jonghwa , Park Jong-Sik , Joo Young Seok , Ryu Mincheol 
Published: March 2016

Abstract
This paper provides the design basis and case study of soil improvement to secure the stability of jack up rig under operation and fabrication condition to effectively mitigate the risk associated with unexpected spudcan penetration. The two penetration curves of spudcan foundation are presented to confirm soil improvement influence using DMM (Deep Mixing Method) with native soil material. The results from 3D large deformation finite element (LDFE) analyses are reported on vertical penetration of skirted spudcan into multilayer clays. The LDFE analyses were carried out using the Coupled Eulerian-Lagrangian (CEL) approach and the modified simple elastic-perfectly plastic Tresca soil model. The seabed sediments were simulated as single layer soft clay with undrained shear strength increasing linearly with depth, two-layer stiff clayey sand overlying soft clay and sandy gravel. The circular block of soil improvement is partially located in the third sandy clay layer under the spudcan penetration path with specific thickness. The result with native soil condition is validated against ISO recommendation and the penetration curve for reinforced section is also overlaid concurrently. The punch-through phenomeneon predicted in the assessement by ISO method is replicated in the numerical analysis. The validation exercise of the original case shows a good agreement and the present numerical approach is capable of predicting the behavior of a spudcan penetration in multi-layered soil. The partially reinforced layer shows the load distribution during spudcan penetration. It provides the reduction of penetration depth under a given preload and seabed conditions efficiently. To ensure the structural stability of jack up rig, the uncertainties of site condition during installation should be removed such as partially trapped soft soil or soft thin layer at the footing location. The presented numerical approach can provide reasonable design basis for soil treatment to mitigate stability risk.
Changes in muscularis propria of anterior vaginal wall in women with pelvic organ prolapse
Authors: Vetuschi A. , D'Alfonso A. , Sferra R. , Zanelli D. , Pompili S. , Patacchiola F. , Gaudio E. , Carta G. 
Published: March 2016

The objective of this study was to evaluate the morphological and immunohistochemical alterations of tissue removed from the upper third of anterior vaginal wall in a sample group of the female population presenting homogenous risk factors associated with Pelvic Organ Prolapse (POP). The case study consisted of 14 patients with POP and there were 10 patients in the control group. Patient selection was carried on the basis of specific criteria and all of the patients involved in the study presented one or more of the recognized POP risk factors. Samples were taken from POP patients during vaginal plastic surgery following Â colpohysterectomy, and from control patients during closure of the posterior fornix following hysterectomy. Samples were processed for histological and Â immunohistochemical analyses for Collagen I and Collagen III, Î±-Smooth Muscle Actin (Î±-SMA), Platelet-Derived-Growth-Factor (PDGF), matrix metalloproteinase 3 (MMP3), Caspase3. Immunofluorescence analyses for Collagen I and III and PDGF were also carried out. In prolapsed specimens our results show a disorganization of smooth muscle cells that appeared to have been displaced by an increased collagen III deposition resulting in rearrangement of the muscularis propria architecture. These findings suggest that the increase in the expression of collagen fibers in muscularis could probably due to a phenotypic switch resulting in the dedifferentiation of smooth muscle cells into myofibroblasts. These alterations could be responsible for the compromising of the dynamic functionality of the pelvic floor.Â
Validation of the Swiss methane emission inventory by atmospheric observations and inverse modelling
Authors: Henne Stephan , Brunner Dominik , Oney Brian , Leuenberger Markus , Eugster Werner , Bamberger Ines , Meinhardt Frank , Steinbacher Martin , Emmenegger Lukas 
Published: March 2016

Abstract. Atmospheric inverse modelling has the potential to provide observation-based estimates of greenhouse gas emissions at the country scale, thereby allowing for an independent validation of national emission inventories. Here, we present a regional-scale inverse modelling study to quantify the emissions of methane (CH4) from Switzerland, making use of the newly established CarboCount-CH measurement network and a high-resolution Lagrangian transport model. In our reference inversion, prior emissions were taken from the "bottom-up" Swiss Greenhouse Gas Inventory (SGHGI) as published by the Swiss Federal Office for the Environment in 2014 for the year 2012. Overall we estimate national CH4 emissions to be 196 ± 18 Gg yr−1 for the year 2013 (1σ uncertainty). This result is in close agreement with the recently revised SGHGI estimate of 206 ± 33 Gg yr−1 as reported in 2015 for the year 2012. Results from sensitivity inversions using alternative prior emissions, uncertainty covariance settings, large-scale background mole fractions, two different inverse algorithms (Bayesian and extended Kalman filter), and two different transport models confirm the robustness and independent character of our estimate. According to the latest SGHGI estimate the main CH4 source categories in Switzerland are agriculture (78 %), waste handling (15 %) and natural gas distribution and combustion (6 %). The spatial distribution and seasonal variability of our posterior emissions suggest an overestimation of agricultural CH4 emissions by 10 to 20 % in the most recent SGHGI, which is likely due to an overestimation of emissions from manure handling. Urban areas do not appear as emission hotspots in our posterior results, suggesting that leakages from natural gas distribution are only a minor source of CH4 in Switzerland. This is consistent with rather low emissions of 8.4 Gg yr−1 reported by the SGHGI but inconsistent with the much higher value of 32 Gg yr−1 implied by the EDGARv4.2 inventory for this sector. Increased CH4 emissions (up to 30 % compared to the prior) were deduced for the north-eastern parts of Switzerland. This feature was common to most sensitivity inversions, which is a strong indicator that it is a real feature and not an artefact of the transport model and the inversion system. However, it was not possible to assign an unambiguous source process to the region. The observations of the CarboCount-CH network provided invaluable and independent information for the validation of the national bottom-up inventory. Similar systems need to be sustained to provide independent monitoring of future climate agreements.
Impacts of European drought events: insights from an international database of text-based reports
Authors: Stahl Kerstin , Kohn Irene , Blauhut Veit , Urquijo Julia , De Stefano Lucia , Acácio Vanda , Dias Susana , Stagge James H. , Tallaksen Lena M. , Kampragou Eleni , Van Loon Anne F. , Barker Lucy J. , Melsen Lieke A. , Bifulco Carlo , Musolino Dario , de Carli Alessandro , Massarutto Antonio , Assimacopoulos Dionysis , Van Lanen Henny A. J. 
Published: March 2016

Abstract. Drought is a natural hazard that can cause a wide range of impacts affecting the environment, society, and the economy. Providing an impact assessment and reducing vulnerability to these impacts for regions beyond the local scale, spanning political and sectoral boundaries, requires systematic and detailed data regarding impacts. This study presents an assessment of the diversity of drought impacts across Europe based on the European Drought Impact report Inventory (EDII), a unique research database that has collected close to 5000 impact reports from 33 European countries. The reported drought impacts were classified into major impact categories, each of which had a number of subtypes. The distribution of these categories and types was then analyzed over time, by country, across Europe and for particular drought events. The results show that impacts on agriculture and public water supply dominate the collection of drought impact reports for most countries and for all major drought events since the 1970s, while the number and relative fractions of reported impacts in other sectors can vary regionally and from event to event. The analysis also shows that reported impacts have increased over time as more media and website information has become available and environmental awareness has increased. Even though the distribution of impact categories is relatively consistent across Europe, the details of the reports show some differences. They confirm severe impacts in southern regions (particularly on agriculture and public water supply) and sector-specific impacts in central and northern regions (e.g., on forestry or energy production). The protocol developed thus enabled a new and more comprehensive view on drought impacts across Europe. Related studies have already developed statistical techniques to evaluate the link between drought indices and the categorized impacts using EDII data. The EDII is a living database and is a promising source for further research on drought impacts, vulnerabilities, and risks across Europe. A key result is the extensive variety of impacts found across Europe and its documentation. This insight can therefore inform drought policy planning at national to international levels.
Hrozba rozvodem ve starém Egyptě (Pražské hieratické ostrakon se soukromým dopisem)
Authors: Vachala Břetislav 
Published: March 2016

V Národním muzeu – Náprstkově muzeu asijských, afrických a amerických kultur v Praze je uloženo zajímavé ramessovské (zřejmě z doby vlády Setchiho II, cca 1201–1196 př.n.l.) hieratické ostrakon (P 2027: obr. 1–3) se soukromým dopisem uspořádaným do 11 řádků. Text obsahuje dopis, který jistá Tachentejšepset adresovala své sestře Ijetě. Žádá ji, aby k ječmenu, který jí současně posílá, přidala pšenici a zpět jí vrátila z toho upečený chléb. Tím by umlčela svého manžela Merimaata, který jí vyhrožuje rozvodem a denně jí vytýká, že její matka ani sourozenci pro ni nic nedělají a ani jim nikdy nedonesou žádné potraviny. Dopis, který napsal velice zkušený písař, pochází zřejmě z některého sídliště v západní oblasti Théb (snad z Dér el-Medíny ?).
Reprezentace muslimské ženy v populární literatuře a její vliv na českou čtenářskou veřejnost
Authors: Čermáková Eva , Linhartová Lenka , Topinka Daniel 
Published: March 2016

Literární trh v České republice byl v posledních dekádách doslova zavalen specifickým typem tzv. ženských románů, zaměřených na osudy žen v prostředí muslimských kultur. Tento žánr zaznamenal enormní popularitu zejména po tragických událostech v USA z 11. 9. 2001. Stereotypní příběhy vykreslující ženu jako oběť patriarchálního systému v islámských zemích se reprodukují v početných variacích a jejich popularita v českém prostředí napomáhá k tvorbě či potvrzení předsudků vůči kulturám muslimských zemí. Studie se zaměřuje na dopad těchto románů na české čtenářky a čtenáře prostřednictvím rozboru komentářů zanechaných na čtenářském serveru www.databazeknih.cz.