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Investigation Of The Interaction Of Co2 And Ch4 Hydrate For The Determination Of Feasibility Of Co2 Storage In The Black Sea SedimentsOrs, Oytun 01 September 2012 (has links) (PDF)
Recently, carbon dioxide injection into deep sea sediments has become one of the carbon dioxide mitigation methods since carbon dioxide hydrates are stable at the prevailing pressure and temperature conditions.
The Black Sea, which is one of the major identified natural methane hydrate regions of the world, can be a good candidate for carbon dioxide storage in hydrate form. Injected carbon dioxide under the methane hydrate stability region will be in contact with methane hydrate which should be analyzed thoroughly in order to increase our understanding on the gaseous carbon dioxide and methane hydrate interaction.
For the storage of huge amounts of CO2, geological structure must contain an impermeable barrier. In general such a barrier may consist of clay or salt. In this study, sealing efficiency of methane hydrate and long term fate of the CO2 disposal under the methane hydrate zone is investigated.
In order to determine the interaction of CO2 and CH4 hydrate and the sealing efficiency of CH4 hydrate, experimental setup is prepared and various tests are performed including the CH4 hydrate formation in both bulk conditions and within sand particles, measurement of the permeability of unconsolidated sand particles that includes 30% and 50% methane hydrate saturations and injection of CO2 into the CH4 hydrate.
Results of the experiments indicate that, presence of hydrate sharply decreases the permeability of the unconsolidated sand system and systems with hydrate saturations greater than 50% may act as an impermeable layer. Also, CO2-CH4 swap within the hydrate cages is observed at different experimental conditions. As a result of this study, it can be concluded that methane hydrate stability region in deep sea sediments would be a good alternative for the safe storage of CO2. Therefore, methane hydrate stability region in the Black Sea sediments can be considered for the disposal of CO2.
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Etude de la formation de l'hydrate de méthane par turbidimétrie <i>in situ</i>Herri, Jean-Michel 02 February 1996 (has links) (PDF)
Lors du transport ou du traitement des effluents pétroliers, on peut observer la cristallisation de particules solides formées à partir d'eau et d'hydrocarbures gazeux : Les hydrates de gaz. Leur formation peut être évitée par ajout d'alcools ou de sels qui déplacent la température de formation (mais qui posent des problèmes de recyclage et de coût compte tenu des quantités utilisées) ou de faibles quantités de polymères qui bloqueraient les mécanismes de cristallisation. Afin d'étudier l'influence des additifs, nous avons développé un appareillage original permettant de mesurer in situ la turbidité d'une suspension de particules dans un réacteur pressurisé. A partir de cette mesure et de la connaissance de l'indice de réfraction des particules, il est possible de calculer la distribution en taille au moyen d'outils mathématiques que nous présentons. Nous donnons également une méthode de calcul théorique de l'indice de réfraction des hydrates de gaz que nous validons expérimentalement avec les hydrates de méthane. Nous étudions ensuite la formation des hydrates de méthane dans un réacteur agité semi fermé de deux litres à partir d'eau liquide et de méthane gazeux. La gamme de température est [0-2°C], la gamme de pression est 30-100 bars et la gamme de vitesse d'agitation est [0-600 rpm]. nous proposons une étude expérimentale du suivi de la vitesse d'absorption du gaz dans le liquide, de la période de latence précédant la formation des premiers cristaux puis de la taille et du nombre des particules en fonction de la pression et de la vitesse d'agitation. Nous étudions également l'influence de l'ajout d'additifs tels que le sable, le chlorure de potassium ou d'un surfactant tel que la polyvinylpyrrolydonne. Nous proposons ensuite une modélisation des mécanismes de cristallisation prenant en compte la germination, la croissance, l'agglomération et la flottaison des particules. Nous validons ce modèle à partir des resultats expérimentaux concernant l'influence complexe de la vitesse d'agitation. À partir des conclusions du modèle, nous examinons ensuite l'influence des additifs.
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Gas production from hydrate-bearing sediments:geo-mechanical implicationsJung, Jongwon 10 November 2010 (has links)
Gas hydrate consists of guest gas molecules encaged in water molecules. Methane is the most common guest molecule in natural hydrates. Methane hydrate forms under high fluid pressure and low temperature and is found in marine sediments or in permafrost region. Methane hydrate can be an energy resource (world reserves are estimated in 20,000 trillion m3 of CH4), contribute to global warming, or cause seafloor instability. Research documented in this thesis starts with an investigation of hydrate formation and growth in the pores, and the assessment of formation rate, tensile/adhesive strength and their impact on sediment-scale properties, including volume change during hydrate formation and dissociation. Then, emphasis is placed on identifying the advantages and limitations of different gas production strategies with emphasis on a detailed study of CH4-CO2 exchange as a unique alternative to recover CH4 gas while sequestering CO2. The research methodology combines experimental studies, particle-scale numerical simulations, and macro-scale analyses of coupled processes.
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HYDRATE PROCESSES FOR CO2 CAPTURE AND SCALE UP USING A NEW APPARATUS.Englezos, Peter, Ripmeester, John A., Kumar, Rajnish, Linga, Praveen 07 1900 (has links)
One of the new approaches for capturing carbon dioxide from treated flue gas (post-combustion capture)
and fuel gas (pre-combustion capture) is based on gas hydrate crystallization. The presence of small amount
of tetrahydrofuran (THF) substantially reduces the hydrate formation pressure from a flue (CO2/N2) gas
mixture and offers the possibility to capture CO2 at medium pressures [1]. A conceptual flow sheet for a
medium pressure hydrate process for pre-combustion capture from a fuel gas (CO2/H2) was also developed
and presented. In order to test the hydrate-based separation processes for pre and post combustion capture
of CO2 at a larger scale a new apparatus that can operate with different gas/water contact modes is set up
and presented.
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GEOLOGIC AND ENGINEERING CONTROLS ON THE PRODUCTION OF PERMAFROST–ASSOCIATED GAS HYDRATE ACCUMULATIONSCollett, Timothy S. 07 1900 (has links)
In 1995, the U.S. Geological Survey made the first systematic assessment of the in-place natural
gas hydrate resources of the United States. That study suggested that the amount of gas in the gas
hydrate accumulations of northern Alaska probably exceeds the volume of known conventional
gas resources on the North Slope. Researchers have long speculated that gas hydrates could
eventually be a commercial resource yet technical and economic hurdles have historically made
gas hydrate development a distant goal rather than a near-term possibility. This view began to
change over the past five years with the realization that this unconventional resource could be
developed in conjunction with conventional gas fields. The most significant development was gas
hydrate production testing conducted at the Mallik site in Canada’s Mackenzie Delta in 2002.
The Mallik 2002 Gas Hydrate Production Research Well Program yielded the first modern, fully
integrated field study and production test of a natural gas hydrate accumulation. More recently,
BP Exploration (Alaska) Inc. with the U.S. Department of Energy and the U.S. Geological Survey
have successfully cored, logged, and tested a gas hydrate accumulation on the North Slope of
Alaska know as the Mount Elbert Prospect. The Mallik 2002 project along with the Mount Elbert
effort has for the first time allowed the rational assessment of the production response of a gas
hydrate accumulation.
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BOTTOM SIMULATING REFLECTORS ON CANADA?S EAST COAST MARGIN: EVIDENCE FOR GAS HYDRATE.Mosher, David C. 07 1900 (has links)
The presence of gas hydrates offshore of eastern Canada has long been inferred from estimated
stability zone calculations, but the physical evidence is yet to be discovered. While geophysical
evidence derived from seismic and borehole logging data provides indications of hydrate occurrence
in a number of areas, the results are not regionally comprehensive and, in some cases, are
inconsistent. In this study, the results of systematic seismic mapping along the Scotian and
Newfoundland margins are documented. An extensive set of 2-D and 3-D, single and multi-channel,
seismic reflection data comprising ~45,000 line-km was analyzed for possible evidence of hydrate.
Bottom simulating reflectors (including one double BSR) were identified at five different sites,
ranging between 300 and 600 m below the seafloor and in water depths of 1000 to 2900 m. The
combined area of the five BSRs is 1720 km2, which comprises a small proportion of the theoretical
stability zone area along the Scotian and Newfoundland margins (~635,000 km2). The apparent
paucity of BSRs may relate to the rarity of gas hydrates on the margin or may be simply due to
geophysical limitations in detecting hydrate.
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GAS HYDRATES AND MAGNETISM: COMPARATIVE GEOLOGICAL SETTINGS FOR DIAGENETIC ANALYSISEsteban, Lionel, Enkin, Randolph J., Hamilton, Tark. 07 1900 (has links)
Geochemical processes associated with gas hydrate formation lead to the growth of iron
sulphides which have a geophysically-measurable magnetic signature. Detailed magnetic
investigation, complemented by petrological observations, were undertaken on cores from a
permafrost setting, the Mackenzie Delta (Canadian Northwest Territories) Mallik region, and
two marine settings, IODP Expedition 311 cores from the Cascadia margin off Vancouver
Island and the Indian National Gas Hydrate Program Expedition 1 from the Bengal Fan.
Stratigraphic profiles of the fine scale variations in bulk magnetic measurements correspond to
changes in lithology, grain size and pore fluid geochemistry which can be correlated on local to
regional scales. The lowest values of magnetic susceptibility are observed where iron has been
reduced to paramagnetic pyrite, formed in settings with high methane and sulphate or sulphide
flux, such as at methane vents. High magnetic susceptibility values are observed in sediments
which contain detrital magnetite, for example from glacial deposits, which has survived
diagenesis. Other high magnetic susceptibility values are observed in sediments in which the
ferrimagnetic iron-sulphide minerals greigite or smythite have been diagenetically introduced.
These minerals are mostly found outside the sediments which host gas hydrate. The mineral
textures and compositions indicate rapid disequilibrium crystallization. The unique physical
and geochemical properties of the environments where gas hydrates form, including the
availability of methane to fuel microbiological activity and the concentration of pore water
solutes during gas hydrate formation, lead to iron sulphide precipitation from solute-rich brines.
Magnetic surveying techniques help delineate anomalies related to gas hydrate deposits and the
diagenesis of magnetic iron minerals related to their formation. Detailed core logging
measurements and laboratory analyses of magnetic properties provide direct ties to original
lithology, petrophysical properties and diagenesis caused by gas hydrate formation.
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HIGH-FLUX GAS VENTING IN THE EAST SEA, KOREA, FROM ANALYSIS OF 2D SEISMIC REFLECTION DATA.Haacke, R. Ross, Park, Keun-Pil, Stoian, Iulia, Hyndman, Roy D., Schmidt, Ulrike 07 1900 (has links)
Seismic reflection data from a multi-channel streamer deployed offshore Korea reveal evidence of hydrateforming
gases being vented into the ocean. Numerous, localised vent structures are apparent from reduced
seismic reflection amplitude, high seismic velocities, and reflector pull-up. These structures penetrate
upward from the base of the gas hydrate stability zone (GHSZ) and are typically several hundred metres
wide, and only a few hundred metres high. Underlying zones of reduced reflection amplitude and low
velocities indicate the presence of gas many kilometers below the seabed, which migrates upward through
near-vertical conduits to feed the vent structures. Where the local geology and underlying plumbing
indicates a high flux of gases migrating through the system, the associated vent structures show the greatest
change of reflector pull-up (the greatest concentration of hydrate) to be near the seabed; where the local
geology and underlying plumbing indicates a moderate flux of gases, the greatest change of reflector pullup
(the greatest concentration of hydrate) is near the base of the GHSZ. The distribution of gas hydrate in
the high-flux gas vent is consistent with the recent salinity-driven model developed for a rapid and
continuous flow of migrating gas, while the hydrate distribution in the lower-flux vent is consistent with a liquid-dominated system. The high-flux vent shows evidence of recent activity at the seabed, and it is likely
that a substantial amount of gas is passing, or has passed, through this vent structure directly into the
overlying ocean.
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ANALYSIS ON CHARACTERISTICS OF DRILLING FLUIDS INVADING INTO GAS HYDRATES-BEARING FORMATIONNing, Fulong, Jiang, Guosheng, Zhang, Ling, Bin, Dou, Xiang, Wu 07 1900 (has links)
Formations containing gas hydrates are encountered both during ocean drilling for oil or gas, as
well as gas hydrate exploration and exploitation. Because the formations are usually permeable
porous media, inevitably there are energy and mass exchanges between the water-based drilling
fluids and gas hydrates-bearing formation during drilling, which will affect the borehole’s
stability and safety. The energy exchange is mainly heat transfer and gas hydrate dissociation as
result of it. The gas hydrates around the borehole will be heated to decomposition when the
drilling fluids’ temperature is higher than the gas hydrates-bearing formation in situ. while mass
exchange is mainly displacement invasion. In conditions of close-balanced or over-balanced
drilling, the interaction between drilling fluids and hydrate-bearing formation mainly embodies
the invasion of drilling fluids induced by pressure difference and hydrate dissociation induced by
heat conduction resulting from differential temperatures. Actually the invasion process is a
coupling process of hydrate dissociation, heat conduction and fluid displacement. They interact
with each other and influence the parameters of formation surrounding the borehole such as
intrinsic mechanics, pore pressure, capillary pressure, water and gas saturation, wave velocity and
resistivity. Therefore, the characteristics of the drilling fluids invading into the hydrate-bearing
formation and its influence rule should be thoroughly understood when analyzing on wellbore
stability, well logging response and formation damage evaluation of hydrate-bearing formation. It
can be realized by establishing numerical model of invasion coupled with hydrate dissociation.
On the assumption that hydrate is a portion of pore fluids and its dissociation is a continuous
water and gas source with no uniform strength, a basic mathematical model is built and can be
used to describe the dynamic process of drilling fluids invasion by coupling Kamath’s kinetic
equation of heated hydrate dissociation into mass conservation equations.
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PALEO HYDRATE AND ITS ROLE IN DEEP WATER PLIO-PLEISTOCENE GAS RESERVOIRS IN KRISHNA-GODAVARI BASIN, INDIAKundu, Nishikanta, Pal, Nabarun, Sinha, Neeraj, Budhiraja, IL 07 1900 (has links)
Discovery of natural methane hydrate in deepwater sediments in the east-coast of India
have generated significant interest in recent times. This work puts forward a possible
relationship of multi-TCF gas accumulation through destabilization of paleo-hydrate in
Plio-Pleistocene deepwater channel sands of Krishna-Godavari basin, India. Analysis of
gas in the study area establishes its biogenic nature, accumulation of which is difficult
to explain using the elements of conventional petroleum system. Gas generated in
sediments by methanogenesis is mostly lost to the environment, can however be
retained as hydrate under suitable conditions. Longer the time a layer stayed within the
gas hydrate stability zone (GHSZ) greater is the chance of retaining the gas which can
be later released by change in P-T conditions due to sediment burial. P-T history for
selected stratigraphic units from each well is extracted using 1-D burial history model
and analyzed. Hydrate stability curves for individual units through time are generated
and overlain in P-T space. It transpired that hydrate formation and destabilization in
reservoir units of same stratigraphic level in different wells varies both in space and
time. Presence of paleo hydrates is confirmed by the occurrence of authigenic carbonate
cement and low-saline formation water. We demonstrate how gas released by hydrate
destabilization in areas located at greater water depths migrates laterally and updip
along the same stratigraphic level to be entrapped in reservoirs which is outside the
GHSZ. In areas with isolated reservoirs with poor lateral connectivity, the released gas
may remain trapped if impermeable shale is overlain before the destabilization of
hydrate. The sequence of geological events which might have worked together to form
this gas reservoir is: deposition of organic rich sediments → methanogenesis → gas
hydrate formation → destabilization of hydrate and release of gas → migration and
entrapment in reservoirs.
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