Dissertations / Theses on the topic 'Offshore characterization'
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1
Mondrago, Quevedo Monica. "Probabilistic modelling of geotechnical conditions for offshore wind turbine support structures." Thesis, Cranfield University, 2014. http://dspace.lib.cranfield.ac.uk/handle/1826/9205.
Full textAbstract:
The geotechnical conditions of the soil can fluctuate greatly across the wind
farm. This is an issue since geotechnical modelling is the base of the structural
design of an offshore wind farm, and the efficient installation of the wind
turbines depends on its accuracy. This paper deals with the characterization of
the seabed, predicting the soil properties over the total affected area by a wind
farm, with the challenge to reduce the required data samples in the site
investigation under the number of installed wind turbines, to reduce its cost.
It is compared the prediction outcome from two different interpolation methods,
kriging and radial basis function, assessing their accuracy by the Mean-Squared
Error and the Goodness-of-Prediction Estimate, as well as with a visual
examination of their mapping; obtaining higher accuracy for radial basis function
and reducing to half the required sample points, from the initial value of installed
wind turbines.
In a second stage it is studied the soil effect over the foundation, analyzing the
results from a FEA, where different geometries of the structure are compared
submitted to different load cases to check its limit states. Those results show
that the foundation cost can increase four times due to the soil conditions,
taking into account only the steel volume, and demonstrating how important is
the soil characterization in the foundation design, as it gives the chance to
relocate those wind turbines that require more expensive foundations.
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Ishutov, Sergey. "Tectonic characterization of the THUMS-Huntington Beach fault, offshore southern California." Thesis, California State University, Long Beach, 2015. http://pqdtopen.proquest.com/#viewpdf?dispub=1591600.
Full textAbstract:
The THUMS-Huntington Beach fault branches from the Palos Verdes fault zone and south of that point forms the southwestern border of the Wilmington and Huntington Beach anticlines. Wilmington and Huntington Beach oil fields are located nearby, with timing and trapping mechanisms closely related to the evolution of the California Continental Borderland. The T-HBF, being part of Inner Borderland, is associated with change in vector of regional stress. Previously, this fault has been interpreted as a discontinuous feature. Correlation of newly acquired 2-D and existing industry 2-D and 3-D seismic and well data made it possible to identify that this is a right-slip fault zone with three segments. The T-HBF is striking northwest and has an average dip of 75° to the northeast. Wilmington and Huntington Beach anticlines are inverted basins formed as structural lows and then uplifted as a result of T-HBF activity in late Miocene-early Pliocene time.
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Raza, Arshad. "Reservoir Characterization for CO2 Injectivity and Flooding in Petroleum Reservoirs, offshore Malaysia." Thesis, Curtin University, 2017. http://hdl.handle.net/20.500.11937/57524.
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Reservoir characterization of the Malaysian gas reservoir for CO2 storage is carried out at preliminary and comprehensive level to provide insight into the storage capacity, injectivity, trapping mechanisms (structural, capillary, dissolution, and mineral), and containment. Screening tools are proposed in this study for the selections of reservoir, injection well, and injection zone along with CO2 residual trapping novel method, experimental assessment of compaction effect and numerical modeling scheme to improve the reservoir characterization.
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Amansure, Giovanni Ricardo. "Source rock characterization of the organic rich intervals of the Taranaki Basin, Offshore New Zealand." University of the Western Cape, 2015. http://hdl.handle.net/11394/5057.
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>Magister Scientiae - MScThe Taranaki Basin is a large (ca. 330,000 km²) sedimentary basin found along the west coast of the northern island of New Zealand. The basin lies partly onshore but mostly offshore below the broad continental shelf to the west of central North Island. The Taranaki Basin is the first sedimentary basin to be explored in New Zealand and is currently New Zealand’s only hydrocarbon producing basin, with approximately 418 million barrels (MMbbl) of oil and 6190 billion cubic feet (bcf) of gas produced by the end of 2011. Most of New Zealand’s known oil and gas accumulations are geochemically typed to coaly facies of Late Cretaceous and Paleogene ages. The main objective of this thesis is to characterize the source rock quality of the organic rich intervals of the Taranaki Basin, namely, the Wainui Member of the North Cape Formation and the Rakopi Formation. The Rakopi Formation comprises terrestrially deposited coal measures, while the North Cape Formation is generally composed of marine rocks. These Formations make up the Pakawau Group. The objective will be achieved using two key methods. Firstly, the derivation of TOC logs using Passey’s log overlay method (Passey et al., 1990) and secondly, the generation of source rock quality maps (i.e. source rock richness mapping and source potential index mapping). This will integrate concepts relating to petrophysical wireline logs, seismic interpretation, core log information, geochemical analysis, depth mapping and isopach mapping. The results obtained from this study confirms the petroleum potential of the organic rich intervals of the Taranaki Basin. Using Passey’s method it was shown that excellent average percent TOC values are encountered for both the Wainui Member of the North Cape Formation and the Rakopi Formation. From source potential index mapping, it can be concluded that the Rakopi formation has a high source potential index (>1000SPI) on the continental shelf, which indicates that it has excellent potential for petroleum generation. The Wainui Member however, shows less potential for petroleum generation on the shelf, this being attributed to generally low net thicknesses on the shelf.
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Africa, Reagan Henry. "Reservoir Characterization using Genetic Inversion and Seismic attributes of Block 1 Orange Basin, Offshore South Africa." University of the Western Cape, 2016. http://hdl.handle.net/11394/5859.
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Magister Scientiae - MSc (Earth Science)Block 1, Orange Basin is located offshore west coast South Africa. This study is focused on providing a solution to performing reservoir characterization in areas where well data is scanty by generating reservoir models using genetic inversion. The study area is represented by the extent of a 1500 km squared 3D seismic survey which is intersected by one well.
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Gigi, Nwabisa. "Reservoir distribution and characterization of lower cretaceous sands in block 2A of Orange Basin, offshore, South Africa." University of the Western Cape, 2017. http://hdl.handle.net/11394/6161.
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Magister Scientiae - MSc (Earth Science)Orange Basin is a volcanic passive margin that forms part of the southwestern basins that were formed during the breakup of South America and Africa in Late Jurassic to Early Cretaceous. The basin comprises of numerous half grabens which are overlain by post rift fluvial deltaic sediments. This research study focuses on the distribution and characterization of the Albian deltaic sands across the Ibhubesi gas field. Geophysical and geological data such as 3D seismic data, wireline logs and core data from four wells (A-G 1, A-K 1, A-V1 and A-K 2) which tested the Albian reservoirs were integrated for a proper evaluation of the reservoirs. From Seismic interpretation and well correlation it is apparent that the Albian sands in the Ibhubesi gas field were deposited in a fluvial-deltaic environment. Seismic attributes have shown that the wells covered by the 3D seismic data were drilled on sweet spots of the channel axis of a deltaic system. These channels seem to be diverted by incised valleys across the entire field. Better sands are expected to develop down dip of the current field as splays in a pro-delta setting. Results obtained from petrography and petrophysical evaluations have revealed that quartzovergrowths are the dominant cement across all the Albian reservoirs of the four wells. Quartz precipitation most likely resulted from the circulation of waters during sediment compaction. Although these Albian sands are highly cemented with silica, porosities in most reservoir intervals range between 18% and 23%. These fairly good porosity values are mostly primary porosities protected from quartz-overgrowth by chlorite rims. The formation of chlorite from volcanic fragments pre-dates the development of quartz-overgrowth; hence the preservation of primary porosities. Secondary porosity is also present in some of the reservoir intervals resulting from leaching of unstable minerals. Permeabilities are generally low due to chlorite rims, quartz overgrowth and other authigenic clays such as kaolinite and illite which blocked pore connectivity. Resistivity logs had generally low readings over most hydrocarbon bearing zones due to the presence of chlorite in the sands.
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Esan, Adegbenga Oluwafemi. "High resolution sequence stratigraphic and reservoir characterization studies of D-07, D-08 and E-01 sands, Block 2 Meren field, offshore Niger Delta." Texas A&M University, 2002. http://hdl.handle.net/1969.1/234.
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Meren field, located offshore Niger Delta, is one of the most prolific oil-producing fields in the Niger Delta. The upper Miocene D-07, D-08 and E-01 oil sands comprise a series of stacked hydrocarbon reservoirs in Block 2 of Meren field. These reservoir sandstones were deposited in offshore to upper shoreface environments.
Seven depositional facies were identified in the studied interval, each with distinct lithology, sedimentary structures, trace fossils, and wire-line log character. The dominant lithofacies are (1) locally calcite-cemented highly-bioturbated, fine-grained sandstones, (middle to lower shoreface facies); (2) cross-bedded, fine- to medium-grained well-sorted sandstones (upper shoreface facies); (3) horizontal to sub-horizontal laminated, very-fine- to fine-grained sandstone (delta front facies); (4) massive very-fine- to fine-grained poorly-sorted sandstone (delta front facies); (5) muddy silt- to fine-grained wavy-bedded sandstone (lower shoreface facies); (6) very-fine- to fine-grained sandy mudstone (lower shoreface facies); and (7) massive, silty shales (offshore marine facies).
Lithofacies have distinct mean petrophysical properties, although there is overlap in the range of values. The highest quality reservoir deposits are cross-bedded sands that were deposited in high-energy upper shoreface environments. Calcite cements in lower shoreface facies significantly reduce porosity and permeability. Integration of core and wire-line log data allowed porosity and permeability to be empirically determined from bulk density. The derived equation indicated that bulk density values could predict 80% of the variance in core porosity and permeability values.
Three parasequence sets were interpreted, including one lower progradational and two upper retrogradational parasequence sets. The progradational parasequence set consists of upward-coarsening delta front to upper shoreface facies, whereas the upward-fining retrogradational parasequence sets are composed of middle to lower shoreface deposits overlain by offshore marine shales.
The limited amount of core data and the relatively small area of investigation place serious constraints on stratigraphic interpretations. Two possible sequence stratigraphic interpretations are presented. The first interpretation suggests the deposits comprise a highstand systems tract overlain by a transgressive systems tract. A lowstand systems tract is restricted to an incised valley fill at the southeastern end of the study area. The alternate interpretation suggests the deposits comprise a falling stage systems tract overlain by transgressive systems tract.
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Lovecchio, Juan Pablo. "Seismic stratigraphy of the offshore basins of Argentina : characterization and modeling of the South Atlantic passive margin dynamics." Electronic Thesis or Diss., Sorbonne université, 2018. https://accesdistant.sorbonne-universite.fr/login?url=https://theses-intra.sorbonne-universite.fr/2018SORUS506.pdf.
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Ce mémoire traite de la formation et de l'évolution des bassins de la marge Atlantique argentine. Trois stades de rifting superposés ont été identifiés dans les bassins des Malvinas et de Colorado/Salado. Le premier événement de rifting est associé à la réactivation extensive, durant le Trias tardif, des chevauchements paléozoïques de la phase de Ventania-Cape. Un deuxième stade de rifting (Jurassique inférieur / moyen) a induit les failles contrôlant les principaux dépocentres et intersectant les structures plus anciennes. Finalement, l’extension du Crétacé inférieur liée à l’ouverture de l’Atlantique Sud s’est concentrée en périphérie de la marge continentale actuelle et a abouti à la mise en place de SDRs. L’évolution du bassin Malvinas a été caractérisée d’un point de vue sismique. Des nouveaux âges zircon U-Pb contraignent le rifting au Jurassique. Le nouveau modèle de rupture du Gondwana présenté ici met l'accent sur l'évolution des bassins mésozoïques péri-atlantiques. L’évolution post-rupture de la marge Atlantique argentine a également été étudiée via l’interprétation sismique et la caractérisation stratigraphique. Après la rupture Hauterivien / Barrémien, trois étapes d'évolution de la marge ont été identifiées. Le Crétacé est marqué par la subsidence thermique des principaux dépocentres. La marge devient une plate-forme continentale unique après la transgression régionale Maastrichtienne-Danienne. Le stade d’expansion du Paléogène est caractérisé par un affaissement et un apport sédimentaire centré au nord dans la région de Salado, tandis que le stade d’expansion du Néogène se caractérise par un comportement cylindrique de l’ensemble de la marge et par l’influence notable des courants de contourThis work is focused on basin formation and evolution in the Argentinean South Atlantic Margin and the Mesozoic breakup of SW Gondwana. Rifting evolution was studied in the Malvinas and Colorado/Salado basins. Three superimposed rifting events were identified in the latter. The first rifting event is associated with the Late Triassic extensional reactivation of Late Paleozoic thrusts of the Ventania-Cape fold belt. A second and main rifting stage (Early-Middle Jurassic) is related to faults forming the main depocenters and intersecting the older structures. Finally, Early Cretaceous extension linked to the opening of the South Atlantic Ocean focused on the outer continental fringe and produced emplacement of SDRs. The rifting evolution of the Malvinas basin was seismically characterized. New zircon U-Pb ages constrain rifting in the Jurassic. A new model for Gondwana breakup is presented with focus on the evolution of the Mesozoic peri-Atlantic basins. The post-breakup evolution of the Argentinean South Atlantic margin was also studied via seismic interpretation and stratigraphic characterization. Three stages of drift evolution were identified. After the Hauterivian/Barremian breakup, the Cretaceous drift unit is conditioned by the thermal subsidence over the main depocenters. Only after the Maastrichtian-Danian regional transgression, the margin becomes a single continental platform. The Paleogene drift stage is characterized by subsidence and sedimentary input centered in the Salado area, while the Neogene drift stage is characterized by a cylindrical behavior and the remarkable influence of contour currents
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VENTRONI, MASSIMILIANO. "On coastal flooding: from extreme offshore wave climate characterization to wave runup simulation with online-coupled numerical models." Doctoral thesis, Università degli Studi di Cagliari, 2017. http://hdl.handle.net/11584/249549.
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Coastal flooding is a topic of great relevance in the context of Coastal Engineering, particularly in the perspective of climate change and related sea level rise. Effective evaluation of coastal flooding at the hindcast, nowcast or forecast level, requires a high degree of interdisciplinary skills because of numerous aspects involved and different space and time scales usually considered. In particular, a peculiar perspective may be depicted by investigating the deep complementarity, as well as the close interrelation, coming up by the combined used of extreme value theory and advanced numerical modelling tools. As a matter of fact, numerical simulations are forced by offshore and/or nearshore boundary conditions, which, in the case of coastal flooding, are usually obtained by long-term statistical predictions of the sea state, related to the extreme regime of wave climate. The aim of this work is primarily focus on analysing and developing an operational methodology for the assessment of coastal flooding induced by extreme waves, with subsequent use of numerical modelling. In particular, the area of interest of wave climate analysis is related to the Sardinian coasts.
It is evident how a reliable specification of boundary conditions is a fundamental component in numerical modelling. First of all, each dataset must formally fulfil correctness, representativeness, reliability and homogeneity characteristics. Unfortunately, even a rigorous assessment of the offshore boundary conditions is affected by an inherent uncertainty, due to the limited spatial and temporal extension which often characterizes a wave-climate dataset source. The sample size largely hinders the effectiveness of the asymptotical hypothesis, which is one of the cornerstones of the extreme value theory. On account of the above limitations, it is therefore still an open question in the literature whether upper limited (e.g. bounded Generalized Pareto) or upper unlimited (e.g. Weibull) distributions are most suitable for engineering purposes. Operationally, an investigation of the adequateness of the dataset at disposal is preliminary carried out. Next, several metrics are used to assess the effectiveness of most popular extreme wave distributions. Finally, the extreme, offshore sea states over the region of interest were computed.
On the other hand, a plethora of numerical models have been implemented within the coastal community, with different levels of accuracy and complexity. A well-known and well-defined focused distinction is represented by the phase-averaged and phase-resolving approach. The main interest of this work is addressed to operational models, where outcomes’ accuracy criteria and non-prohibitive computational burden requirements should be well-balanced and properly considered. With this purpose in mind, an online coupling implementation between a spectral phase-averaged model and a non-hydrostatic phase-resolving model is provided. Specifically, two open-source models have been adopted as model components: the spectral SWAN model and the non-hydrostatic SWASH model.
To sum up, the long term meteo-marine climate over the Sardinian coasts is evaluated first, by considering both mean and extreme characteristics of a heterogeneous dataset, previously deeply-corrected, ranging from waves to wind fields. From this, it is relatively straightforward to compute the offshore-boundary conditions. Second, a numerical coupled model involving two open source state-of-the-art models, was implemented, in order to enable a seamless and accurate chain simulation of an extreme sea state from offshore up to the shore.
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Conti, Claudio. "Small-scale physical modelling of piled foundations for offshore wind turbines application." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2019.
Find full textAbstract:
Nowadays, finding alternative energy sources is becoming more and more important. Europe is particularly focusing on wind energy and in offshore wind energy especially. An issue concerning offshore wind energy which is gaining more and more attention is the noise emissions due to impact driven pile foundation. The noise caused by the installation process has been judged as “potentially dangerous for marine fauna” from the German Authorities.
This research thesis is part of a project which examines a viable alternative installation method for the displacement of pile foundations for offshore wind energy called pile jacking. This technology should be developed to be cost-efficient, flexibly scalable and to produce considerably reduced vibration and air pollution emissions during its placement in the sea bed. Jacked piles technology would eliminate almost any noise deriving from the hammer impact.
As most offshore piled foundations have been installed by impact driving technology, the question arises as to how piles with different the stiffness and the capacity , can otherwise be installed.
In order to delineate the significant variables affecting the load-bearing capacity and especially the ultimate uplift capacity of a pile in saturated sand, a small-scale test campaign in scale 1:30 has been performed at the Test Center for Support Structures in Hanover. The campaign was supervised by the Department for Support Structures of Fraunhofer IWES. A testing schedule comprising of 15 small-scale geotechnical physical experiments was conducted on open-ended piles to an embedded length of 75 cm using two method of pile installation: static jacking and impact driving.
The aim of this thesis is to obtain preliminary experimental data and set out the main features of this technology.
The results obtained by this study reveal that static jacking installation lead to higher resistances and is overall beneficial to the mechanical load bearing behavior of pile foundations.
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Beyene, Mussie Abraham. "Modelling the Resilience of Offshore Renewable Energy System Using Non-constant Failure Rates." Thesis, Uppsala universitet, Institutionen för elektroteknik, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-445650.
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Offshore renewable energy systems, such as Wave Energy Converters or an Offshore Wind Turbine, must be designed to withstand extremes of the weather environment. For this, it is crucial both to have a good understanding of the wave and wind climate at the intended offshore site, and of the system reaction and possible failures to different weather scenarios. Based on these considerations, the first objective of this thesis was to model and identify the extreme wind speed and significant wave height at an offshore site, based on measured wave and wind data. The extreme wind speeds and wave heights were characterized as return values after 10, 25, 50, and 100 years, using the Generalized Extreme Value method. Based on a literature review, fragility curves for wave and wind energy systems were identified as function of significant wave height and wind speed. For a wave energy system, a varying failure rate as function of the wave height was obtained from the fragility curves, and used to model the resilience of a wave energy farm as a function of the wave climate. The cases of non-constant and constant failure rates were compared, and it was found that the non-constant failure rate had a high impact on the wave energy farm's resilience. When a non-constant failure rate as a function of wave height was applied to the energy wave farm, the number of Wave Energy Converters available in the farm and the absorbed energy from the farm are nearly zero. The cases for non-constant and an averaged constant failure of the instantaneous non-constant failure rate as a function of wave height were also compared, and it was discovered that investigating the resilience of the wave energy farm using the averaged constant failure rate of the non-constant failure rate results in better resilience. So, based on the findings of this thesis, it is recommended that identifying and characterizing offshore extreme weather climates, having a high repair rate, and having a high threshold limit repair vessel to withstand the harsh offshore weather environment.
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Binyatov, Elnur. "Sedimentological, Cyclostratigraphic Analysis And Reservoir Characterization Of Balakhany X Formation Within The Productive Series Azeri Field On C01 Well (offshore Azerbaijan)." Master's thesis, METU, 2008. http://etd.lib.metu.edu.tr/upload/3/12609628/index.pdf.
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The Azeri, Chirag, Gunashli (ACG) field is located offshore Azerbaijan.
The reservoirs are multilayered sandstones forming traps within a major anticlinal
structure. Proven crude oil reserves are estimated to contain 5.4 billion barrels of
oil. In the past this area has been studied in regional detail but not at the reservoir
scale with respect to the fluvio-deltaic sediments filling the northern shore of the
ancient South Caspian Sea.
The aim of this study is carried out the sedimentological,
cyclostratigraphical analysis and reservoir characterization of Balakhany X
Formation within the Productive Series which is considered to be one of the
significant producing horizons. To be able to achieve this objective, a 30m thick
section, which is mainly composed of siliciclastics, has been studied in detail on
Balakhany X cores from C01 well Azeri field.
In this study, detailed lithofacies analyses were performed and sandstone,
mudstone, siltstone facies were recognized in the studied interval of the
Balakhany X Formation. Litharenites and sublitharenites sandstones are the most
abundant in the succession. Sedimentological analysis such as grain-size
sphericity, provenance, XRD, SEM and grain surface texture were performed and
their relationship with depositional environment were discussed. The grain size
distribution of the samples along the succession shows distribution of fine to very fine sands. Sorting of sandstones ranges between moderately well to very well
sorted. The provenance analysis of sandstones based on modal analysis of thin
sections related to recycled orogen. According to interpretation of grain size
parameters and grain surface textures analysis the main transporting agent of
sands observed as wind, wave and river agents.
High resolution cyclostratigraphy studies based on cm-m scaled cyclic
occurrences of lithofacies along the measured section were performed.
Milankovitch, sub-Milankovitch and millennial cycles were determined along the
studied section.
The petrophysical analysis revealed good to very good (18 to 24%)
porosity and good permeability (10 to 538mD) in Balakhany X Formation.
The porosity and permeability are affected by both textural and
compositional controls. Grain size distribution along the reservoir section is fine
to very fine sands. Influence of compaction was observed by the fractures and
dissolutions on the sand grains. The calcite cement, grain-size variation, sorting
and compaction are the main factors controlling porosity and permeability.
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Borges, De Salles Abreu Carlos Eduardo. "Time-lapse (4D) seismic interpretation methodologies based on kriging analysis : application to the Senlac (onshoreCanada) and Marlim ( offshore Brazil) heavy oilfields." Thesis, Vandoeuvre-les-Nancy, INPL, 2008. http://www.theses.fr/2008INPL012N/document.
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L’objectif de la thèse est de développer une méthodologie permettant d’obtenir une interprétation quantitative des données de sismique répétée (sismique 4D). Une étape essentielle consiste à évaluer la répétitivité des données, puis à filtrer les bruits indésirables, qui peuvent masquer ou détériorer la signature 4D. Une méthodologie basée sur des outils géostatistiques a été développée. Deux fenêtres temporelles des cubes sismiques étudiés sont choisies, l’une au-dessus du réservoir - où aucun effet 4D n’est attendu - et l’autre incluant le réservoir. Une analyse statistique et variographique conduite sur ces différentes fenêtres permet de proposer une décomposition des variogrammes en structures communes ou indépendantes, qui sont ensuite interprétées en termes de bruit, de signature géologique ou 4D. Les structures interprétées comme indépendantes de la géologie ou de la production sont ensuite filtrées à l’aide de la technique du krigeage factoriel proposée par Matheron en 1982. La méthodologie a été testée sur deux cas réels. Le premier concerne un champ d’huiles lourdes canadien, sur lequel trois campagnes sismiques ont été enregistrées, avant et pendant la production obtenue à l’aide d’injection de vapeur. Le bruit interprété comme tel sur les 3 campagnes a été filtré à l’aide la méthode décrite plus haut ; une analyse en termes de faciès sismiques non supervisée a ensuite été conduite sur les données brutes et filtrées afin d’évaluer l’intérêt du filtrage. Finalement, une interprétation des décalages en temps observés entre campagnes a été proposée. Le deuxième cas réel concerne un champ turbiditique profond dans l’offshore du Brésil, sur lequel deux campagnes sismiques 3D ont été acquises, avant et après le début de la production obtenue par injection d’eau. Le bruit présent sur les deux campagnes a été filtré à l’aide de la technique du krigeage factoriel, et la qualité de ce filtrage a pu être évaluée par comparaison avec d’autres techniques couramment utiliséesThis thesis research aims at investigating seismic interpretation methodologies and techniques that will help on better characterizing time-lapse, or 4D, seismic signatures. These techniques and methodologies are used to evaluate the time-lapse repeatability and then to filter out undesirable artefacts that are non-related to the production, while enhancing the 4D signature. To achieve these goals, a methodology based on geostatistical tools, was developed. Typically, at least two time-interval windows are considered: one above and the other comprising the reservoir of interest. A statistical and variographic analysis, conducted on both windows and on all surveys, leads to an interpretation step where common or independent structures – in the variographic sense- can be pointed out. The structures interpreted as not related to the geology or to the production mechanism are filtered from the data by a multivariate factorial cokriging technique, based on the concept of Kriging Analysis developed by Matheron in 1982. Two real case time-lapse studies were used to test the methodology. The first case is a Canadian onshore heavy oil reservoir submitted to steam injection, where three different time-lapse surveys were shot to monitor the steam-chamber evolution. The noise present in the three surveys was first filtered using the technique described above; next, an unsupervised seismic facies analysis was conducted on both raw and filtered data in order to evaluate the filtering technique, and finally an interpretation, in terms of reservoir properties changes, of the time-shit observed between the campaigns was proposed. In the second case, the seismic data was acquired on a deepwater turbiditic oilfield from Brazil at two different times of reservoir life, before and after production and water injection. The two seismic surveys were filtered using the factorial kriging technique; the quality of the filtering was, in this case, evaluated by comparison with more common techniques
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Bou, Daher Samer Verfasser], Ralf [Akademischer Betreuer] [Littke, and Rudy [Akademischer Betreuer] Swennen. "Source rock characterization and petroleum generation modelling of the Levant Basin, onshore-offshore Lebanon : an integrated approach / Samer Bou Daher ; Ralf Littke, Rudy Swennen." Aachen : Universitätsbibliothek der RWTH Aachen, 2016. http://d-nb.info/1130151352/34.
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Bou, Daher Samer [Verfasser], Ralf [Akademischer Betreuer] Littke, and Rudy [Akademischer Betreuer] Swennen. "Source rock characterization and petroleum generation modelling of the Levant Basin, onshore-offshore Lebanon : an integrated approach / Samer Bou Daher ; Ralf Littke, Rudy Swennen." Aachen : Universitätsbibliothek der RWTH Aachen, 2016. http://d-nb.info/1130151352/34.
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Badescu, Adrian Constantin. "Reservoir characterization of the Miocene Starfak and Tiger Shoal fields, offshore Louisiana through integration of sequence stratigraphy, 3-D seismic, and well-log data." Access restricted to users with UT Austin EID, 2002. http://wwwlib.umi.com/cr/utexas/fullcit?p3108452.
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Patruno, Stefano. "Geological characterization of sand-prone subaqueous delta systems : a case study of the Upper Jurassic Sognefjord Formation (Troll Field, Northern North Sea, offshore Norway) and global examples." Thesis, Imperial College London, 2013. http://hdl.handle.net/10044/1/39827.
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Core sedimentology, stratigraphic architecture and 3D seismic geomorphology are integrated in order to: (a) demonstrate the criteria for recognition of coarse-grained subaqueous deltas in the stratigraphic record; (b) compare them with modern examples; (c) develop a new method to extract progradation rates from ancient shallow-marine clinoforms; and (d) refine the depositional model of the Upper Jurassic Sognefjord Formation, which forms the main reservoir in the super-giant Troll Field (Norwegian North Sea). The Sognefjord Formation is a 10-200 m thick clastic wedge, deposited in ca. 6 Myr, by a fully marine deltaic system that was sourced from the Norwegian mainland. A series of 10-60 m thick, westerly-dipping subaqueous clinoform sets are developed within this unit and can be mapped for several tens of kilometres along strike. Within each clinoform set, clinothems are formed by regressively stacked sandstone-rich bedsets, devoid of subaerial facies and separated by thin mudstone intervals. Near-horizontal trajectories are observed in each clinoform set, and the sets are stacked vertically. In the eastern half of the field, individual clinoforms are relatively gently dipping (1-6°) and bound thin (10-30 m) clinothems dominated by fine-grained, hummocky cross-stratified sandstones. Towards the west, clinoforms gradually become steeper (5-14°) and bound thicker (15-60 m) clinothems that comprise medium-grained sandstones in their upper parts. Topsets are usually well developed. Quantification of clinoform age and progradation rates is constrained by regionally correlatable bioevents, and relies on exponential age-depth interpolations. The facies break that mirrors the foreset-to-bottomset transition, which represents storm wave base, is subsequently dated, and progradation rates are measured along transects tied to well correlations and seismic interpretations. The results indicate falls in progradation rate (from 500 to 30 km/Myr) and net sediment flux (from 90 to 10 km2/Myr), and a simultaneous rise in vertical sedimentation rate (from 15 to 70 m/Myr) towards the basin; these variations are attributed to the progradation of the subaqueous delta into progressively deeper waters associated with along-shore currents that provide net sediment transport out of the study area, as well as sculpting the linear, elongated clinoforms. Coarse-grained subaqueous deltas provide a new interpretative template that may be applicable to other ancient clinoform-bearing shallow-marine sandstones with reservoir potential, whilst calculation of progradation rates provides a tool to improve reservoir characterisation and near-field exploration by enhancing prediction of reservoir distribution and character.
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Hsieh, Chi-Hsun, and 謝奇勳. "Geochemical characterization of crude oils from Offshore Taiwan." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/kb588u.
Full textAbstract:
碩士國立臺北科技大學
資源工程研究所
100
In addition to commercial amount of natural gas with condensates, crude oils have been discovered in the syn-rift Paleogene formation of the Taihsi Basin and Penghu Basin and in the Neogne formation of the Taihsi Basin, respectively. The geochemical characterization of these crude oils may indicate their source organic matter and maturation level, and therefore are meaningful from the viewpoint of petroleum exploration. Five oil samples, i.e., four crude oils and one condensate, were studied for their geochemical characteristics based on the chemical group composition, hydrocarbons composition revealed from gas chromatography, and the biomarker distributions from the gas chromatography-mass spectrometry. The results show the oils from the syn-rift Paleogene formation of the Taihsi Basin and Penghu Basin share similar geochemical characteristics. They are high waxy and comprised of high content of saturated hydrocarbons with biological markers derived from phytoplankton. The occurrence of 4-methyl steranes implies these oils generated from source rocks of lacustrine environment with low maturity. The oil samples of the post-rift Neogene formation of the Taihsi Basin shows geochemical characters significantly different from those of the syn-rift Paleogene formation of the Taihsi and Penghu Basins. The crude oil sample from the early Miocene Mushan Formation of the E structure, Taishi Basin, was distinguished as a low-mature oil generated from coals. The crude oil sample from the early Miocene Peiliao Formation is the mixture of the coal derived oil and mature oil from terrestrial source rocks. The condensate sample of the Shiti Formation from the gas field of the B Block, Taishi Basin is of low maturity and contains a lot of terrigenous biomarkers. The existence of the lacustrine oils confirms the lacustrine petroleum system of the syn-rift sequences in the Taishi and Penghu basins. This petroleum system differs from the post-rift coal-bearing petroleum system of the Neogene formation.
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Casey, Michael Chase. "Integrated Reservoir Characterization: Offshore Louisiana, Grand Isle Blocks 32 & 33." Thesis, 2011. http://hdl.handle.net/1969.1/ETD-TAMU-2011-05-9363.
Full textAbstract:
This thesis integrated geology, geophysics, and petroleum engineering data to build a detailed reservoir characterization models for three gas pay sands in the Grand Isle 33 & 43 fields, offshore Louisiana. The reservoirs are Late Miocene in age and include the upper (PM), middle (QH), and lower (RD) sands. The reservoir models address the stratigraphy of the upper (PM) sand and help delineate the lower (RD) reservoir. In addition, this research addresses the partially depleted QH-2 reservoir compartment. The detailed models were constructed by integrating seismic, well log, and production data. These detailed models can help locate recoverable oil and gas that has been left behind.
The upper PM model further delineated that the PM sand has several areas that are shaled-out effectively creating a flow barrier within reservoir compartments. Due to the barrier in the PM-1 reservoir compartment, an area of potentially recoverable hydrocarbons remains. In Grand Isle 33, the middle QH sand was partially depleted in the QH-2 reservoir compartment by a series of development wells. Bottom hole pressure data from wells in Grand Isle 32 & 33 reveal that the two QH fault compartments are in communication across a leaking fault. Production wells in the QH-1 compartment produced reserves from the QH-2 compartment. The lower RD sand model helped further delineate the reservoir in the RD-2 compartment and show that this compartment has been depleted. The RD model also shows the possible presence of remaining recoverable hydrocarbons in the RD-1 compartment. It is estimated that about 6.7 billion cubic feet of gas might remain within this reservoir waiting to be recovered. A seismic amplitude anomaly response from the QH and RD sands is interpreted to be a lithologic indicator rather than the presence of hydrocarbons. Amplitude response from the PM level appears to be below the resolution of the seismic data. A synthetic seismogram model was generated to represent the PM and surrounding sands. This model shows that by increasing the frequency of the seismic data from 20 Hz to a dominant frequency of 30 Hz that the PM and surrounding sands could be seismically resolvable. Also the PM-1 compartment has possible recoverable hydrocarbons of 1.5 billion cubic feet of gas remaining.
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VANNUCCHI, VALENTINA. "Wave energy harvesting in the Mediterranean Sea." Doctoral thesis, 2013. http://hdl.handle.net/2158/797871.
Full textAbstract:
ITALIANO. Gli obiettivi principali di questa tesi sono la caratterizzazione sottocosta della potenza ricavata dal moto ondoso in aree italiane non ancora studiate o poco studiate e l'ottimizzazione di dispositivi per la conversione dell’energia disponibile dal moto ondoso (WEC - Wave Energy Converters), nei due punti maggiormente energetici di ciascuna area. I dispositivi studiati sono un corpo oscillante (il caso di studio più semplice) fissato al fondale marino per mezzo di un sistema di conversione di energia e di un dispositivo galleggiante a colonna d'acqua oscillante chiamato Spar Buoy OWC e studiato presso l'Istituto di Ingegneria Meccanica (IDMEC) dell’Istituto Superiore Tecnico (IST) di Lisbona. La caratterizzazione sottocosta è stata ottenuta mediante simulazioni numeriche effettuate con il MIKE21- Spectral Wave, un modello spettrale di onda che permette la simulazione di fenomeni come l'interazione non lineare onda-onda, la dissipazione dovuta all’attrito con il fondale, la dissipazione indotta dal frangimento delle onde, la rifrazione e lo shoaling dovuti alla variazione della profondità. Come condizioni al contorno in mare aperto sono stati utilizzati i valori di altezza d'onda, periodo di picco, direzione media e fattore di diffusione estratti dal modello PREVIMER MENOR-4000M. Le aree analizzate sono: la Toscana Settentrionale (La Spezia - Livorno), la Toscana Centrale (Livorno - Piombino), la Liguria Occidentale (Ventimiglia - Imperia), la Sardegna Nord-Occidentale (Stintino - Alghero). Per i due climi d’onda corrispondenti ai punti maggiormente energetici di ciascuna area sono stati ottimizzati i due dispositivi studiati (corpo oscillante ancorato al fondale e Spar Buoy OWC) in base alla geometria e al sistema di conversione dell’energia. L’ottimizzazione è stata effettuata massimizzando delle funzioni obiettivo che tenessero conto del costo, dell'efficienza e delle prestazioni del dispositivo.
INGLESE. The main purposes of this thesis are the nearshore wave energy characterization in Italian areas not yet analysed or little analysed and the optimization, in the two locations with the highest wave power of each area, of devices for the Wave Energy Conversion (WEC). The analysed devices were a single floating body linked to the seabed by means of a Power Take Off (PTO) mechanism (the simplest case of study) and of the Spar Buoy Oscillating Water Column (OWC), an axisymmetric floating OWC that was studied at Institute of Mechanical Engineering (IDMEC) of the Instituto Superior Técnico (IST) in Lisbon. The nearshore characterization is computed with numerical simulations that were carried out by the MIKE21-Spectral Wave, a spectral wind-wave model based on unstructured mesh that allows the simulation of the phenomena as non-linear wave-wave interaction, dissipation due to white-capping, dissipation due to bottom friction, dissipation due to depth-induced wave breaking, refraction and shoaling due to depth variations. As offshore boundary conditions the values of wave height, peak period, average direction and spreading factor, of the points extracted by the MENOR-4000M PREVIMER model on a depth of 100 m, were used. This methodology is applied to four selected areas: the North of the Tuscany coast (La Spezia – Livorno), the centre of the Tuscany coast (Livorno – Piombino), the Western part of Liguria coast (Ventimiglia – Imperia) and the North-West of the Sardinia coast (Stintino – Alghero). The device optimization was performed for the geometry and for the PTO system in local wave climates selected for each area. The optimization procedure followed different criteria that consisted in maximizing objective functions, in order to consider the cost, particularly useful in the fully commercial stage, the efficiency and the performance of the devices.
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Kumar, Pushpendra, H. C. Das, K. Anbazhagen, Hailong Lu, and John A. Ripmeester. "STRUCTURAL CHARACTERIZATION OF NATURAL GAS HYDRATES IN CORE SAMPLES FROM OFFSHORE INDIA." 2008. http://hdl.handle.net/2429/1102.
Full textAbstract:
The dedicated gas hydrate coring/drilling program was carried out under National Gas
Hydrate Program (NGHP) in four Indian offshore areas (Kerala-Konkan, Krishna-
Godavari, Mahanadi and Andman) during 28th April to 19th August, 2006. During
NGHP Expedition 01, 2006, total of 39 holes were drilled/cored at 21 sites in these areas.
The gas hydrates have been found to be present in large quantities in Indian offshore
areas particularly in KG basin. More than 130 confirmed solid gas hydrate samples were
recovered during this hydrate coring/drilling program. The laboratory analysis was
carried out on the 34 natural gas hydrate samples recovered from offshore India. The gas
hydrate characterization was carried out using the microscopic techniques such as
Raman, 13C NMR and XRD for its structure, cavity occupancy and hydration number.
The gas hydrates occur in grayish green fine sediments, gray medium sands and white
volcanic ash as pore-filling hydrate and massive hydrates in fractured shale/clay. The
visible massive gas hydrates developed especially at Site NGHP 1-10B, 10C, 10D and
21A in K G area. The structures of the gas hydrates in the studied samples are all sI, with
methane as the dominant guest molecule. The occupancy of methane in large cage is
almost complete, while it is variable in the small cage (0.75 to 0.99). The hydration
number is 6.10 ± 0.15 for most of the hydrates in the samples studied. This paper presents
the results of the laboratory analysis on the structural characterization of natural gas
hydrates in core samples from offshore India.
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Chien, Hsin-Hsin, and 簡新心. "Isolation and Characterization of Family Methanomicrobiaceae Species from Potential Methane Hydrate area Offshore SW Taiwan." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/82260223515476768881.
Full textAbstract:
碩士國立中興大學
生命科學系所
104
The intensive investigation at offshore southwestern of Taiwan, including Bottom Simulating Reflector, high methane and dissolved sulfide concentrations and shallow depth of sulfate-methane interface, indicated that this area could be the potential gas hydrate bearing area. Most of methane here was biogenic origin and produced by methanogens. To explore the community and diversity of methanogens in the potential gas hydrate bearing area and related methane seeps and mud volcano habitats, the sediments were inoculated to the methanogen basal media (MB/W) with acetate, formate and methanol as the catabolic substrate to enrich the methanogens. Further sub-transfer with or without antibiotics, rich/minimal medium, serial dilution and roll tube techniques were performed to obtain the pure isolate. After the pure methanogen isolate was clarified, the phylogenetic relationships of 16S rRNA gene sequences, morphological and physiological characterizations were analyzed. Methanogenic strain CYW5 and strain S4BF were enriched from core sediment samples at deep sea Mud Volcano MV5 and MV4, respectively. Cells of strain CYW5 was irregular coccids, 0.9 to 2.0 m in diameter and lysed easily by 0.01% SDS treatment. Strain CYW5 utilized formate or hydrogen plus carbon dioxide as catabolic substrates for methanogenesis. The optimal growth conditions were 37℃, 0.043 to 0.085 M NaCl and pH 6.02 to 7.32. Phylogenetic analysis revealed that strain CYW5 was closely related to Methanogenium cariaci JR1T (95.39% 16S rRNA gene sequence similarity). Based on the phylogenetic characteristic, it is evident that strain CYW5 represents a novel genera and species of the family Methanomicrobiaceae. The 16S rRNA gene sequence analysis indicated that strain S4BF showed 98.89% identity with Methanogenium marinum AK-1T, but the growth range of temperature was varied. Methanogenium marinum AK-1T could not grow over 25℃, but strain S4BF could grow at 37℃. Compared to other species of Methanogenium, strain S4BF had lower salinity tolerance. It was indicated that strain S4BF may be a candidate as a novel Methanogenium species. Through isolating novel methanogens from gas hydrate bearing area, we could gain insight into the community and function of methanogenic archaea in the deep sea sediment and gas hydrate bearing area. The discovery and conservation of noval genus and noval species could not only increase the diversity and taxonomy of microorganism but also the resource of energy and application of biotechnology.
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Zhang, Wei-Ling, and 張瑋玲. "Isolation and Characterization of Family Methanocellaceae Species from Potential Methane Hydrate Area Offshore SW Taiwan." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/4cabua.
Full textAbstract:
碩士國立中興大學
生命科學系所
106
Methane, also known as natural gas, is one of the most important sources of energy that humans often use. Gas hydrates usually forms when methane and water freeze at high pressures and relatively low temperatures. They are widely distributed, clearest and the largest source of hydrocarbons on Earth. Enormous volumes of gas hydrate (methane hydrate) are considered as one of the new alternative energy in the 21st century. To explore the diversity of methanoarchaea at deep sea gas hydrate habitats, we tried to isolate methanogen from sediment samples of the gravity core collected at station 22 at KP-9 area southwestern Taiwan from ORIII-1368 cruise in 2009. The methanogen enrichment cultures were incubated in minimal and rich methanogen basal media with formate, acetate or methanol as substrate for methanogenesis. After the enrichment strategies combined the serial sub-transfer and vancomycin addition to inhibit the growth of bacteria, a pure and novel hydrogenotrophic methanogen, strain CWC-04, was obtained. Cells of strain CWC-04 were rod-shape (1.4-2.9 μm long by 0.5-0.6 μm wide) with flagellum.The phylogenetic analyses of the 16S rRNA gene confirmed its affiliation with Methanocellales, and Methanocella arvoryzae MRE50T was the most closely related species. The sequence identities of 16S rRNA gene between strain CWC-04 and MRE50T were 93.67%. Strain CWC-04 utilized H2+CO2, formate, formate+acetate, 2-propanol or 2-butanol as catabolic substrates and growth occurs at 20-45°C (optimally at 42°C), at pH 5.35-7.31 (optimum pH 5.35) and with less than 0.68 M of NaCl (optimum 0.17 M). Rifampicin was inhibit the growth of strain CWC-04 but tetracycline was not. The genome size of strain CWC-04 was 3.19 Mb and the DNA G+C content as determined by genome sequencing, was 46.19 mol%. Of the 1175 COGs identified within the strain CWC-04, all but 53 were identified within other Methanocella species, and 947 (80.60%) orthologue groups were shared by all COGs. Based on the morphological, phylogenetic and genomics characteristics presented here, it is evident that strain CWC-04 represents a novel genus and new species of family Methanocellaceae. The optical density of CWC-04 culture dropped abruptly upon entering the late-log growth phase and the virus-like particles (170 nm in diameter) were observed on and around the cells. This observation demonstrated strain CWC-04 harbors a lytic virus. The spherical shape with a diameter of 170 nm and a blackberry-like envelope of the virion was named as VMce (Virus of Methanocella). The investigation of the methane based ecosystem under sea have been focused mainly in the relation within methane producer, bacterial syntroph and AOM. The occurrence of methanoarchaeal viruses suggested the rapid carbon cycling may play a role in this methane based ecosystem.
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Lee, Kuan-Yi, and 李冠誼. "Isolation and Characterization of Genus Methanobacterium Species from Marine Methane Hydrate Habitat Offshore SW Taiwan." Thesis, 2019. http://ndltd.ncl.edu.tw/cgi-bin/gs32/gsweb.cgi/login?o=dnclcdr&s=id=%22107NCHU5105052%22.&searchmode=basic.
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Weng, Chieh-Yin, and 翁杰愔. "Isolation and Characterization of Methanoculleus and Methanosarcina from deep sea marine sediment offshore SW of Taiwan." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/73013147295837212131.
Full textAbstract:
碩士國立中興大學
生命科學系所
102
Taiwan is situated on the boundary separating the Eurasian plate to the west from the Philippine Sea Plate to the east. There were complex landforms from SW of Taiwan, such as ridges, mud volcanos, cold seeps and gas hydrate bearing regions. The isotopic data from Prof. Tsan-Yao Yang’s lab was suggested that most of the methane produced in Taiwan methane hydrate potential area is biogenic origin. To explore the methanogens at methane seeps or hydrate habitats, sediment samples obtained from piston core at Tainan Ridge, Good Weather Ridge, 96 Mud Volcano and Deformation Front by ORI (Ocean Reasearch I) cruises were enriched anaerobically. After anaerobic enrichment and serial sub-transfer, Methanoculleus sp. S3Fa from 96 Mud Volcano Groups was purified and characterized by MS Mei-Fei Chen. The 16S rRNA sequence of strain S3Fa showed 99% similarity with deep sea gas hydrate isolate Methanoculleus submarinus. Similar isolation methods were used in this study, three strains CYW1, CYW2 and CYW3, were purified from Deformation Front, Tainan Ridge and Good Weather Ridge, respectively. The 16S rRNA sequence of three strains showed 99% similarity with Methanosarcina mazei Go1. The whole-cell protein profile of strain CYW1, CYW2 and CYW3 are identical with M. mazei N2M9705. The irregular cocci cells of Methanoclleus sp. CYW4 was isolated from Defromation Front and showed 96-97% similarity with genus Methanoculleus. Strain CYW4 used H2 plus CO2 or formate as catabolic substrates. The optimum growth condition was 37°C, pH 8.02 and 0.08 M NaCl. The result showed that strain CYW4 was the novel new species and might be the new clade in genus Methanoculleus. It is expected that these methanogens isolated from methane seep and gas hydrate potential bearing regions contribute to the methane hydrate formation.
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Chen, Mei-Fei, and 陳眉霏. "Isolation and Characterization of Methanoarchaea from sediments of Methane Hydrate potential area offshore SW of Taiwan." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/4f98hp.
Full textAbstract:
碩士國立中興大學
生命科學系所
101
To solve the energy shortage problem, the alternate energy methane (gas) hydrates which are estimated at about twice the amount of all other known fossil fuel reserves, are distributed along coastal margins, like SW offshore of Taiwan, as well as in terrestrial regions and marine sediments. With 74% of methane on earth are biogenic origin, this represents a significant source of natural gas from biological methanogenesis. Isotopic data from professor Yang Tsan-Yao at National Taiwan University suggested that most of the methane produced in Taiwan methane hydrate potential area is biogenic origin. To explore the methanogen diversity at methane seep or hydrate habitats, sediment samples obtained from piston and gravity cores at 96 Mud Volcano groups, Fangliao Canyon and KP-9 region by ORI and ORIII cruises were anaerobic enriched for methanogens. After serial sub-transfer and anaerobic roll-tube incubation, genus as Methanoculleus, Methanofollis, Methanosarcina, Methanococcoides and Methanogenium were partially purified. Among them, the irregular coccoid cells of Methanoculleus sp. S3Fa from the core sediment of 96 Mud Volcano Groups were purified. The 16S rDNA sequence of the strain S3Fa showed 99 % similarity with Methanoculleus marisnigri and M. submarinus (isolated from methane hydrate at Nankai Trough, Japan). Comparison of the 16S rRNA sequences of sediment samples with related uncultured environment samples showed that methanogenic phylotypes are close related with clones from marine sediment of submarine mud volcanos at East Mediterranean Sea, methane hydrate-bearing sites and oil reservoir sites. The results suggests that those phylotype of methanogens maybe important in methane hydrate formation.
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Wang, Chengshu. "Velocity estimation from seismic data by nonlinear inversion and characterization of gas hydrate deposits offshore Oregon." Thesis, 2003. http://wwwlib.umi.com/cr/utexas/fullcit?p3116457.
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Teng, Nai-Hsuan, and 鄧乃瑄. "Isolation and Characterization of Methanofollis Species from Potential Cold Seep Area-Four Way Closure Ridge Offshore SW Taiwan." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/jw54qx.
Full textAbstract:
碩士國立中興大學
生命科學系所
106
Four Way Closure Ridge is an anticlinal ridge that represents an ideal trap for methane hydrate accumulations through the analyses of high-resolution bathymetry, deep-towed sidescan sonar imagery, high-resolution seismic profiling and towed video observations of the seafloor. Four Way Closure Ridge is one of the sites with intensive methane seepages to bring up a typical cold seep used methane as substrate chemosynthetic community and with highly dense mussel bed with shrimps, crabs and clams was found at this site. A mesophilic, hydrogenotrophic methanogen, strain FWC-SCC2, was isolated from deep-sea sediment obtained at the C5-6 station at Four Way Closure Ridge region by the R/V Ocean Researcher III during ORIII-1900 cruise in 2015. Phylogenetic analysis revealed that strain FWC-SCC2 was most closely related to Methanofollis tationis Chile 9T (98.2% 16S rRNA gene sequence similarity) and share 96-98 % 16S rRNA gene sequence similarity with other valid Methanofollis species. Genome relatedness between strain FWC-SCC2 and Methanofollis genus was computed using both average nucleotide identity (ANI) and genome-to-genome distance analysis (GGDA) with values of 78.2-79.8% and 17.8-23.8%, respectively. Based on the morphological, phenotypic and phylogenetic characteristics presented here, it is suggested that strain FWC-SCC2 represents a new species of genus Methanofollis. The cells were irregular cocci, non-motile with 0.8-1.2 μm in diameter. The Mr of surface-layer protein was 116.4 kDa. Strain FWC-SCC2 used H2/CO2 or formate as catabolic substrates. The growth conditions were at 20-40C, 0-0.85 M NaCl and pH 5.9-8.2. Comparative genomic analysis between strain FWC-SCC2 and other Methanofollis reveals strain FWC-SCC2 have 38 unique COGs, included ABC-type iron transport system FetAB, quinol monooxygenase YgiN, two type aerotolerant COGs and phage shock protein A that can maintain cell membrane integrity.
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Lee, Jia-Fang, and 李佳芳. "Applying seismic attribute analysis for gas hydrate distribution and characterization in the Yung-An Ridge area offshore southwestern Taiwan." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/49169200001571881895.
Full textAbstract:
碩士國立臺灣大學
海洋研究所
100
Yung-An Ridge is a structural high located in the accretionary complex of the Luzon subduction-collision system offshore southwestern Taiwan. Bottom simulating reflectors (BSRs) are widespread in the region, and combined geophysical and geochemical investigations have revealed that large amount of gas hydrates and free gases are accumulated beneath the ridge and adjacent slope basins on both sides of the Yung-An Ridge where high priority drilling sites for gas hydrate investigation are proposed. It is thus important to have a good understanding of the potential gas hydrate reservoir characters there. This study applies seismic attribute analysis (SAA) technique to analyse a 3D seismic volume data and three large offset multi-channel seismic reflection data in the Yung-An Ridge area. Seismic attribute analyses of the 3D seismic data help us to better constrain the geological features identified in the 3D seismic volume. The reflection strength analyses show that in addition to the high amplitude character of BSRs, we have also observed some very strong reflection signals below BSRs in the slope basins on both sides of the Yung-An Ridge. Instantaneous frequency images show that there are low frequency patches beneath BSRs which may reflect gas-bearing strata. The analyses of instantaneous phase images help to identify faults easily. The SAA results suggest that there is little or no gas hydrate presence beneath the Penghu Canyon, while in the slope basin to the west of the Yung-An Ridge, characters of buried channel deposits are clearly visible. There are widely distributed high amplitude reflections in the slope basin to the east of the Yung-An Ridge suggesting the presence of large amount of free gases. A fault structure has been identified at the eastern edge of the slope basin which terminates the high amplitude reflections. The gas chimney character of the fault feature suggest that this fault forms a good conduit for gas migration.
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Wei, Wen-Hsin, and 魏文心. "Isolation and characterization of genus Methanoculleus species and their viruses from deep sea marine sediment offshore SW of Taiwan." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/mw9qr3.
Full textAbstract:
碩士國立中興大學
生命科學系所
106
Viruses infect all Three Domains of lifes, however the knowledge of archaeal viruses is limited. Lately, the diverse virus morphology and the independent virus development outside the extreme thermophilic/acidophilic archaeal host attracted the attention on archaeal virus investigations. Currently, over 100 archaeal viruses have been discovered, most related to thermophilic Crenarchaea and extreme halophilic Euryarchaea. However, almost none methanoarchaeal virus was reported for the past two decades. From the core sediment on the top of gas hydrate habitat in the deformation front site offshore south-western Taiwan, Methanoculleus taiwanensis CYW4T was enriched, isolated and characterized. Cell lysis was observed at stationary phase and a lytic virus which caused the lysis of strain CYW4T was observed under TEM. The spherical shape virion, about 100 nm, with the icosahedral capsids and envelope was named as VMta (Virus of Methanoculleus taiwanensis). VMta is a dsDNA virus which contained 70,262 bp with a mol% G+C content of 54.5 and 101 putative open reading frames (ORFs). Base on the VMta genome information and analysis through BLASTX and HHpred, it was suggested that the VMta may injected the DNA into the host by the puncture protein and replicated their genomes through the rolling-circle replication (RCR) mechanism. The viral DNAs were packed into the empty capsid by the terminase enzymes and virons left host cell with the endolysin disruption. Methanoculleus sp. CWC-02 were enriched from the marine sediment of the Good weather ridge. Phylogenetic analysis revealed that strain CWC-02 was closely related to Methanoculleus marisnigri JR1T (98.4% 16S rRNA gene sequence similarity). Genome relatedness between strain CWC-02 and Methanoculleus marisnigri JR1T was computed using both average nucleotide identity (ANI) and genome-to-genome distance calculator (GGDC) with values of 86.81% and 32.50%, respectively. According to genomic data, it is patent the strain CWC-02 may the novel new species. Strain CWC-02 used H2 plus CO2, formate, 2-propanol and 2-butanol as catabolic substrates. The optimum growth temperature was 37℃. The stationary phase growth of strain CWC-02 cells also observed virus-like particles under TEM. The occurrence of methanoarchaeal viruses at the methane (gas) hydrate ecosystems indicated that viruses may play a role in acceleration of the carbon and nutritional cycling.
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Chen, Yu-Wei, and 陳宇維. "Isolation and Characterization of Genus Methanoculleus strain FWC-SCC1 from Marine Cold Seep at Four-Way Closure Ridge Offshore SW Taiwan." Thesis, 2019. http://ndltd.ncl.edu.tw/cgi-bin/gs32/gsweb.cgi/login?o=dnclcdr&s=id=%22107NCHU5105050%22.&searchmode=basic.
Full textAbstract:
碩士國立中興大學
生命科學系所
107
A mesophilic, hydrogenotrophic methanogen, strain FWC-SCC1, was isolated from deep-sea sediment from the C5-6 station at Four-Way Closure Ridge offshore southwestern Taiwan by the Ocean Researcher Ⅲ cruiser, OR3-1900, in 2015. Through the analyses of high-resolution bathymetry, deep-towed sidescan sonar imagery, high-resolution seismic profiling and towed video observation of seafloor, etc. Taiwan gas hydrate research team demonstrated the geological structure of Four-Way Closure Ridge should have rich methane hydrate accumulation. In addition, this area was confirmed with intensive methane leakage to form a typical cold seep, which include chemosynthetic microbial community and the organism symbiosis with the methane-oxidation microbes. Phylogenetic analysis revealed that strain FWC-SCC1 was most closely related to Methanoculleus taiwanensis CYW4T (97.22% 16S rRNA gene sequence similarity). Genome relatedness between strain FWC-SCC1 and Methanoculleus taiwanensis CYW4T was computed using both average nucleotide identity (ANI) and genome-to-genome distance analysis (GGDA) with values of 81.4% and 23.5%. Above genome analyses support strain FWC-SCC1 should be a new species of Methanoculleus. Cells of strain FWC-SCC1 were irregular cocci, with 0.8-1.2 μm in diameter and with flagella. The Mr of surface-layer protein was 120 kDa. The methanogenic substrates utilized by strain FWC-SCC1 were formate and H2/CO2. The growth conditions were at 15-45°C (optimum, 37°C), 0-1.17 M NaCl (optimum, 0.085 M) and pH 5.64-7.98 (optimum, pH 5.64). The gemone size of strain FWC-SCC1 was 3.16 Mb and the G+C content of the chromosomal DNA as determined by genome sequencing, was 61.16 mol%. There was one CRISPR/Cas system in the genome of strain FWC-SCC1, indicated that the sample was infected by virus before. Based on the morphological, phenotypic and phylogenetic characteristics, it is evident that strain FWC-SCC1 represents a novel species of the genus Methanoculleus. The optical density of FWC-SCC1 culture dropped abruptly upon entering the late-log phase and the virus-like particles on the cells were observed under TEM. These results demonstrated strain FWC-SCC1 may be infected by virus. Methanosarcina and Methanoculleus were the major methanogens found in cold seep of Four-Way Closure Ridge offshore SW Taiwan. These methanogens are considered to be the suppliers of methane for marine methane hydrate.
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Kılıç, Cem Okan. "Characterization and quantification of middle Miocene reservoirs of starfak and tiger shoal fields, offshore Louisiana, using genetic sequence stratigraphy and neural-networks." Thesis, 2004. http://hdl.handle.net/2152/1342.
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Kılıç, Cem Okan Fisher W. L. "Characterization and quantification of middle Miocene reservoirs of starfak and tiger shoal fields, offshore Louisiana, using genetic sequence stratigraphy and neural-networks." 2004. http://repositories.lib.utexas.edu/bitstream/handle/2152/1342/kilicc91229.pdf.
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Iranpour, Mohammad. "FATIGUE CHARACTERIZATION OF RISERS AND PIPELINES UNDER REALISTIC VARIABLE AMPLITUDE LOADING AND THE INFLUENCE OF COMPRESSIVE STRESS CYCLES." Thesis, 2013. http://hdl.handle.net/10222/50472.
Full textAbstract:
One of the most prominent factors affecting the performance and longevity of risers is vortex induced vibration (VIV), which can cause severe fatigue damage, especially in risers used in deep waters. The available approaches for analyzing VIV induced fatigue in risers mainly focus on the VIV aspect of the problem; indeed less attention has been paid on the effect of VIV on a riser’s fatigue life and in prediction of fatigue life using various models.
This dissertation first demonstrates how one can characterize fatigue of pipes and risers using an equivalent plate specimen as opposed to using a pipe specimen, thereby simplifying the task, yet obtaining good accuracy. Actual variable amplitude loadings (VAL) are used to study the fatigue crack growth in risers’ material with a focus on the various influencing parameters. Extensive experimental investigations are performed, followed by analytical and computational nonlinear finite element analyses. It is shown that the higher harmonics do cause significant fatigue damage, thus their influence should not be ignored. The influence of load interaction effects is also investigated, focusing on the fatigue crack growth retardation effects due to tension overloads, as well as the acceleration effects due to compression underloads. The crack closure concept is then used to explore into both the fatigue retardation and acceleration effects within a VAL scenario. An effective method for calculation of the stress intensity factor is proposed, which considers only the tensile portion of the stress range, while proposing another effective approach for accounting for the influence of compressive stress cycles.
Moreover, a two-parameter approach is used in this dissertation, relating the fatigue crack growth rate (FCGR) to the crack tip opening displacement (CTOD). It is shown that the CTOD provides adequate information for calculating the FCGR under VAL, and it can be effectively used to account for the influence of the compressive stress cycles. The experimental investigation also considers the retardation effect resulting from the applied peak tensile overload cycles (TOLC) and the influence of various so-called “clipping” levels, demonstrating the significant influence of the TOLC on crack growth retardation in VAL.