| NO. |
Title |
Presented at
&
Date |
Author |
Project Team / Research Division |
| Abstract |
| 11094 |
Real-time Seismic Cable System |
EGU General Assembly 2006
2006/4/2-7 |
Eichi Asakawa(JGI, Inc.), Yuji Kawai(Nippon Salvage Co., Ltd.), Hiroo Takahashi(OCC Corporation), Yukitoshi Ogasawara(Kokusai Cable Ship Co., Ltd.), Tatsuo Saeki(Japan Oil, Gas and Metals National Corporation)
|
Geology & Geophysics Research Team |
[Abstract] A new real-time seafloor seismic observation system has been developed by NSC, OCC and KCS. It was initially intended for large scale terrestrial crustal structure survey, and has since been modified for oil/gas exploration with the support of the JOGMEC. The system is named "Real-time Seismic Cable System(RSCS)". It is a series of 3-component geophones and telemetry opto-electronics equipped into a high pressure resistant housing, which are connected by optical submarine cable. The seismic data is immediately transferred to observation ship through the cable during acquisition. This system enables us to monitor the sensor's data stream in real time. By changing the sensors spacing, it can be used for refraction seismic surveys with a large spacing of around 3km, for reflection seismic surveys with a short spacing of 50m, and for natural seismic observation with spacing up to 20km.
RSCS has great advantages over the conventional OBS system, such as(1)Real-time data acquisition, (2)Accurate positioning, (3)Precise timing with GPS link on board and (4)Superior sensor directivity. Moreover this system can be operated in ultra deep sea up to 8000m, whereas the current industrial OBC system has a maximum operation depth of 2000m.
A refraction seismic survey has already been carried out, and natural seismic activity is currently being monitored at the seabed. Further, a reflection seismic survey will be tested very soon. The data quality so far is very good compared to the conventional OBS systems. The RSCS has a great potential as a seabed observation system.
|
|
|
| 11089 |
Study of rock drilling by laser-induced underwater shock
waves |
The Third International Symposium on Interdisciplinary
Shock Wave Research
2006/3/1 |
K. Ohtani, D. Numata, S.H.R. Hosseini, M. Sun, K. Takayama(Tohoku
University), A. Abe, M. Katayama(CRC Solution Corp.), T. Kobayashi,
K. Otomo(Japan Drilling Co., LTD.) |
Petroleum Engineering Research Team |
[Abstract] Related to the laser induced shock wave
research we recently became interested in application
of high-power laser to rock drilling. Reed et al. [1]
used 1.6 kW pulsed Nd: YAG laser to drill a rock specimen
submerged in a 2 mm thick water layer. The rock was molten
rather than cracked by spalling. The molten rock surface
was quickly solidified to form a glassy layer and nullified
further increase of drilling effects. The elongated laser
exposure time did not significantly deepen the drilling
hole but simply heated up the rock specimen. We have been
interested in the application of laser-induced underwater
shock waves through their focusing or jet forming effects
to rock drilling. Such uses of underwater shock waves
are closely related to the extension of the medical applications
of extracorporeal shock wave lithotripsy (ESWL) and pulsed
Ho: YAG laser induced liquid jet [2].
This paper reports a preliminary result of laser-induced
underwater shock wave applied to rock drilling. Experimental
results were compared with AUTODYN numerical simulations.
Time resolved shadowgraph of underwater shock wave focusing
from a truncated ellipsoidal cavity is shown in Fig.1.
The ellipsoidal cavity made of brass had major radius
of 35.25 mm and minor radius of 25.0 mm. Q-switched Ruby
laser of 670 mJ, wavelength of 69.4 nm, 25ns pulse duration
was deposited in the focal point inside the cavity. We
observed the process of shock focusing to the second focal
point outside the cavity and high pressure formation by
using a high-speed digital video recording (HPV-1, SHIMADZU
Corp., frame rate up to 1,000,000 f/s, spatial resolution
of 312 pixel x 260 pixel). Consequently, the high pressures
built up at the second focus point cracked the rock specimen
without creating thermal damages. We plan further parametric
studies by increasing laser energy in muddy sea water |
|
|
| 11087 |
Characterization of Physical Properties of Methane Hydrate-bearing
Zone |
The 10th International Symposium on Recent Advances
in Exploration Geophysics(RAEG2006)
2006/3/30-31 |
Masami Hato, Yosuke Minami (Kyoto University), Takao
Inamori (Japan Oil, Gas and Metals National Corporation),
Toshifumi Matsuoka (Kyoto University) |
Methane Hydrate Research Project Team |
| [Abstract] In order to understand a mechanism of peculiar phenomena
on the seismic section such as frequency-dependency of
BSR appearance and blanking, we have tried to model the
elastic velocity in the methane hydrate-bearing layer
in the Nankai Trough area by referring to the well logging
information. By detailed investigation on the velocity
extracted from the sonic date, we found that we can delineate
the methane hydrate-bearing zone as a random heterogeneous
media which can be written by bi-modal Gaussian velocity
distribution and von Karman-type autocorrelation function.
After modeling the physical model of the media by specific
values of elastic parameters such as P-and S-wave velocity,
we carried out elastic wave simulation and then compared
the synthetic seismogram with real seismic date. As a
result, we found fine similarity between synthetic and
real date. These results show us assumption of physical
model of methane hydrate-bearing zone reasonable. |
|
|
| 11086 |
Hydrogen Production by Steam Reforming of Dimethyl Ether
over Single Type Copper Catalysts |
1st International Symposium on Hydrogen from Renewable
Sources and Refinery Applications
2006/3/28 |
Kaoru Takeishi, Akane Arase (Shizuoka University) |
Research Project Team on Emerging Gas Technologies |
| [Abstract] Dimethyl ether (DME) is expected as one of clean fuels,
and DEM is one of substitutes of diesel fuels and LPG.
Infrastructures of LPG will be able to use for DEM. Then,
DEM steam reforming for hydrogen production was studied.
Copper alumina catalysts prepared by a sol-gel method
produced large quantities of H2 and CO2 at 300 ℃. Other
metal alumina catalysts produced H2 and CO2, but also
produced large quantities of CO. Our studies showed that
copper is the best metal for the production of H2 while
producing less CO. Á-alumina for DEM hydrolysis into methanol,
and copper for methanol steam reforming to H2 and CO2
coexist on the surfaces of catalysts prepared by the sol-gel
method, and the catalysts produce more H2 from DEM than
impregnation catalysts, mixed catalysts, and so on. We
have developed a great potential for H2 supply from DEM. |
|
|
| 11085 |
JOGMEC's Current GTL Research and Development for Utilization
in the Future |
Gas-to-Liquids & Coal to-Liquids Conference (AJM(The
Australian Journal of Mining))
2006/3/23 |
Yoshifumi Suehiro (Japan Oil, Gas and Metals National
Corporation) |
Research Project Team on Emerging Gas Technologies |
E Introduction
E JOGMEC-GTL
E A-ATG
E D-CPOX
E Conclusions |
|
|
| 11081 |
Evaluation of Experiment Program 2004:Natural Hydrate
Exploration Campaign in the Nankai-Trough Offshore Japan |
2006 IADC/SPE Drilling Conference
2006/2/21-23 |
Maki Matsuzawa, Satoru Umezu (Japan Drilling Co., Ltd.)
, Koji Yamamoto (Japan Oil, Gas and Metals National Corporation) |
Methane Hydrate Research Project Team |
[Abstract] Ministry of Economy, Trade and Industry (METI) of Japan
has decided to carry out the 16 years research and development
program of natural methane hydrate (MH) resources and
set up the Research Consortium for Methane Hydrate Resources
in Japan (MH21) in 2001.
In 2004, a multi-well exploration campaign in the Nankai-Trough
was conducted as a national project led by METI. It was
organized by Japan Oil, Gas and Metals National Corporation
(JOGMEC) in collaboration with Japan Petroleum Exploration
Co., Ltd. (JAPEX) and Teikoku Oil Co., Ltd. (TOC) as drilling
operators. All scheduled programs were performed with
deepwater research vessel "JOIDES Resolution"
operated by Transocean. There were 30 wells drilled mainly
for geological research purposes and 2 wells drilled for
engineering experiment purposes during this campaign.
The purpose of experiment was to obtain the engineering
data and to verify technologies which would be required
for the future possible production from the natural hydrate
offshore of Japan. The following experiments, which were
1) Drilling fluids applicability for borehole stability,
2) Monitoring the downhole pressure and temperature while
drilling, 3) Cementing, 4) Formation / fracture pressure
measurements, 5) Capability to horizontally drill unconsolidated
formations and hydrate layers in very shallow section
below the seabed, was conducted by drilling 2 wells in
19 days. This experiment program was undertaken by Japan
Drilling Co., Ltd. (JDC) under contract with JOGMEC for
the planning and for the analysis of obtained data, and
with JAPEX for the operation.
As a result of the experiment, effectiveness of the drilling
fluids which ware used to the borehole stability was confirmed.
The specially designed cement slurry covered up the hydrate
formations. The pressure measurement executed at several
points including the hydrate formations by using Cased
Hole Dynamics Tester (CHDT*) acquired effective data.
The horizontal well was executed almost on the planned
path and it was able to drill 300m length of the hydrate
layers including 100m length of horizontal section at
340mTVD below the seabed.
A further research and development is scheduled to be
promoted with the method completion of the production
test well. |
|
|
11075
|
Hydrogen production with steam reforming of dimethyl
ether over copper alumina single-type catalyst
|
PACIFICHEM 2005
2005/12/16 |
Kaoru Takeishi, Yoshimi Akaike(Shizuoka University) |
Research Project Team on Emerging Gas Technologies
|
| [Abstract] Dimethyl ether (DME) is expected as one of clean fuels,
and DME is one of substitutes of diesel fuels and LPG.
Infrastructures of LPG will be able to use for DME. Then,
DME steam reforming for hydrogen production was studied.
Copper alumina catalysts prepared by a sol-gel method
produced large quantities of H2 and CO2 at 300 ℃. Other
metal alumina catalysts produced H2 and CO2, but also
produced large quantities of CO. Our studies showed that
copper is the best metal for the production of H2 while
producing less CO. Á-alumina for DME hydrolysis into methanol,
and copper for methanol steam reforming to H2 and CO2
coexist on the surfaces of catalysts prepared by the sol-gel
method, and the catalysts produce more H2 from DME than
impregnation catalysts, mixed catalysts, and so on. We
have developed a great potential for H2 supply from DME. |
|
|
11073
|
Current status of DME - reforming system for PEFC and
Comparison of hydrogen supply methods for Fuel Cell Vehicles
|
INTERGAS III
2005/12/20
|
Osamu Okada(Renaissance Energy Research Corporation),
Tetsuya Takemoto(Osaka Gas Co., Ltd.), Kengo Tsukahara(Mitsubishi
Gas Chemical Co., Inc.), Hiroshi Hashimoto(JGC Corporation),
Naohiko Matsuda(Mitsubishi Heavy Industries, Ltd.), Shinichi
Suzuki(Japan Oil, Gas and Metals National Corporation)
|
Research Project Team on Emerging Gas Technologies
|
[Abstract] Current status of DME-reforming
system for PEFC and comparison of hydrogen supply methods
for Fuel Cell Vehicles
1. Comparison of Generation Systems -Conventional Method
2. Utilization of Natural Gas (NG) - well and the Technology
of GTL and DME
3. DME is one of the most suitable feedstock for the hydrogen
production.(Methanol is also suitable, but it is toxic
and hard to handle one.)
4. Implementation system of this study
5. Comparison of methanol and DME in steam reforming reaction
on Cu-Zn type catalyst
6. Carbon Containing Gas Composition after DME Steam Reforming
at 350℃(except H2, H2O)
7. Reaction activity of DME steam reforming on improved
catalyst
8. Durability test of Cu-Zn-Al-type catalyst - Reaction
temperature;350℃, GHSV;2000h-1, H2O/DME;5
9. Reforming methods for on-board reforming FCV
10. Scale up of the production method of Cu/Zn precipitate
of DME reforming catalyst
11. Reforming reactor(structure)
12. Structure of auto-thermal reformer (new development)
13. Volume and weight of H2 supply system
14. Schedule
15. Example of Hydrogen Storage Metal Hydride Container
16. Improved Design of Hydrogen Storage Metal Hydride
Container
17. Well-to-Wheel Efficiency for Various Vehicle Scenarios
18. Conclusion |
|
|
11072
|
Multiphase Flow Meter for Intensive Water Cut Monitoring
at Abu Dhabi
|
KIPCE (Second Kuwait International Petroleum Conference
& Exhibition) 2005
2005/12/11 |
Tomoko Watanabe(Japan Oil, Gas and Metals National Corporation),
Marwan Hamad (Zakum Development Company), Teiji Saito
(Japan Oil Development Co., Ltd.), Zhenyan LI (OVAL Corporation)
|
Petroleum Engineering Research Team
|
[Abstract] Vertical sweep efficiency in
heterogeneous carbonate reservoirs is one of the largest
uncertainties of the reservoir management for five-spot-pattern
water flooding in Abu Dhabi. The continuous water cut
monitoring is one of key elements to understand the water
breakthrough mechanism, the heterogeneity of the reservoirs,
and fluid flow in well bores and to optimize reservoir
management by water flooding operation in these reservoirs.
Installation of multiphase flow meters (MPFMs) may enable
to provide the operators with continuous and real-time
water cut data. To establish a program to utilize JOGMEC/OVAL
MPFM for reservoir monitoring, the two sets of the JOGMEC/OVAL
MPFM were installed and commissioned in a giant offshore
oil field in Abu Dhabi, and the monitoring of well streams
was conducted from August 2002 to December 2004.
The MPFMs apply a new turbine system consisting of twin-rotors
with spring and one mixer, which has succeeded cost reduction
by removing gamma ray densitometry, and its compact size
achieves easy installation.
The MPFMs custom-made for the liquid production range
of 5,300-8,100 BLPD continuously measured oil and gas
rates within +/-10% relative error and water cut within
+/-3% error. The high accuracy of the MPFM monitoring
liquid and gas rate was confirmed by the referential test
separator data. However further confirmation is required
for water cut monitoring by MPFMs, because enough referential
sampling data were not available for comparison of water
cut. On the other hand, it was confirmed that the accuracy
of the reference data directly affects the water cut.
Therefore, more samples of accurate reference data are
indispensable for good result of MPFM monitoring and also
the MPFM needs to take measures for reducing the error
of the water cut.
It was learned from the experience of this field trial
that the most important point for the improvement of any
MPFM is for MPFM vendors and operators to confirm the
ability of MPFMs with using “the accurate reference data”
in the same fields. It will enable operators to confirm
the true ability of MPFMs in the fields and use MPFMs
as a reliable reservoir-monitoring tool for better reservoir
management. |
|
|
11070
|
Temperature distribution and variation in methane hydrate
bearing sediments in the eastern Nankai Trough, Japan
|
2005 AGU (American Geophysical Union) Fall Meeting
2005/12/8 |
Tetsuji Fujii, Sadao Nagakubo, Tatsuji Kawasaki (Japan
oil, Gasand Metals National Corporation), Masafumi Fukuhara,
Kasumi Fujii (Schlumberger)
|
Methane Hydrate Research Project Team
|
[Abstract] In the Nankai Trough, seismic
data indicates widespread existence of BSR, which is interpreted
as an indicator of bottom boundary of methane hydrate
bearing zone. Methane hydrate is regarded as future possible
natural gas resource, however the mechanisms of its occurrence
and distribution have been poorly understood. In order
to obtain data for the understanding of methane hydrate
occurrence and natural reserves estimation, METI exploratory
test wells efTokai-oki to Kumano-nada” were drilled from
January to May in 2004 in the eastern Nankai Trough, offshore
central Japan. As a part of this project, continuous formation
temperature measurement in hydrate bearing sediments in
ocean area, the first attempt in the world, was carried
out in order to investigate in-situ temperature condition
in hydrate bearing sediments and to obtain basic data
to evaluate methane hydrate occurrence.
Optical fiber sensor was used for the measurement of
temperature distribution. Sensor cable was set in the
borehole, with the measurement system (data logger) set
above the seafloor. 2 kinds of sensor cable, DTS (Distributed
Temperature Sensor) and FBG (Fiber Bragg Grating), were
set in the borehole. Continuous temperature distribution
data for 50 days was obtained successfully at the location
where pore space type hydrate was confirmed in sand layers
by well logging and coring. Averaged temperature depth
profile was constructed after analysis such as data conversion,
quality control, evaluation of temperature stability,
temperature correction and depth correction (Fukuhara
et al., 2005).
The thermal gradient obtained from temperature depth
profile showed good matching with expected thermal gradient
in this area (3C/100m), below hydrate bearing zone. On
the other hand, apparent lower thermal gradient was observed
in hydrate bearing zone and the vicinity of lower BSR.
Preliminary estimation of bottom depth of a hydrate stability
zone (BGHS) from phase diagram with measured temperature
data suggested significant depth discrepancy between theoretical
BGHS and BSR. The variation of thermal gradient within
and below hydrate bearing zone could be brought by the
exothermic or endothermal reactions accompanied by hydrate
formation or dissociation. Further analysis using core,
well log and seismic data would bring us useful information
for understanding this complicate temperature variation.
This study was conducted as a part of research consortium
for methane hydrate resources in Japan (MH21). |
|
|
11069
|
BSR pull-up phenomena in the Kumano Basin
|
2005 AGU (American Geophysical Union) Fall Meeting
2005/12/5-9 |
Tatsuo Saeki, Takao Inamori (Japan Oil, Gas and Metals
National Corporation), Sumito Morita (National Institute
of Advanced Industrial Science and Technology, AIST)
|
Methane Hydrate Research Project Team
|
| [Abstract] Conventionally, the BSR (bottom simulating reflector),
which is considered to be a bottom of the gas hydrate
bearing sediment, has been used for delineation of horizontal
distributions of gas hydrate layers and their base structures.
Through the BSR interpretation study of the Kumano Basin
in the Eastern Nankai Trough, Japan using the 3D seismic
cube, BSR pull-up phenomena were detected. Most remarkable
BSR pull-up phenomenon occurred in the small circle area
of which diameter was 400m and its center was closed to
the sea-floor in which the pock-mark existed. Strictly
speaking, the pull-upped reflector canft be called as
the BSR, because it dose not simulate the sea-bottom.
However, it may suggest the local change of the phase
boundary depth due to the thermal condition or some other
reasons. At the meeting, we will show details of phenomena
and technical discussions. |
|
|
11068
|
Time structure analysis of BSRs using 3D seismic data
in the Eastern Nankai Trough, Japan
|
2005 AGU (American Geophysical Union) Fall Meeting
2005/12/7 |
Sadao Nagakubo, Takao Inamori, Toshiaki Kobayashi, Tetsuya
Fujii (Japan Oil, Gas and Metals National Corporation)
|
Methane Hydrate Research Project Team
|
| [Abstract] According to the result of METI Exploratory Wells "Tokai-Oki
to Kumano-nada" conducted in FY2003 in Japan, it
is suggested that methane hydrate bearing layers in the
Eastern Nanakai Trough distribute heterogeneously above
BSRs (Bottom Simulating Reflectors). To understand the
heterogeneity of distribution of methane hydrate bearing
layers and explore concentrated hydrate bearing layers,
we conducted a detailed analysis of time-structure map
of BSR using 3D seismic survey data acquired in the Eastern
Nankai Trough. Since P-wave velocity of hydrate bearing
layers are high, it was expected that two-way-time from
sea bottom to BSR is short above concentrated hydrate
bearing layers compared to hydrate bearing zones. Although
significant anomalies are recognized on time-structure
map, it seems that anomalies are corresponding to heterogeneous
thermal-structure in preference to distribution of hydrate
bearing layers around surveyed area. It should be considered
that these thermal anomalies are depending on fluid migration
with hydrocarbons through faults, unconformities and permeable
sand layers from deeper formations. Since occurrences
of methane hydrates are strongly restricted by temperature
and pressure, analysis of time-structure of BSR acquired
by seismic data could be helpful to understand the accumulation
mechanism of methane hydrates in sediments. |
|
|
11067
|
Origin of Methane Gas and Migration Through The Gas
Hydrate Stability Zone Beneath The Permafrost Zone
|
2005 AGU (American Geophysical Union) Fall Meeting
2005/12/5 |
Takashi Uchida, Amane Waseda (Japan Petroleum Exploration
Co., Ltd.), Takatoshi Namikawa (Japan Oil, Gas and Metals
National Corporation)
|
Methane Hydrate Research Project Team
|
[Abstract] In 1998 and 2002 Mallik wells
were drilled at Mackenzie Delta in the Canadian Arctic
that clarified the characteristics of gas hydrate-dominant
sandy layers at depths from 890 to 1110 m beneath the
permafrost zone. Continuous downhole well log data as
well as visible gas hydrates have confirmed pore-space
hydrate as intergranular pore filling within sandy layers
whose saturations are up to 80% in pore volume, but muddy
sediments scarcely contain.
Plenty of gas hydrate-bearing sand core samples have been
obtained from the Mallik wells. According to grain size
distributions pore-space hydrate is dominant in medium-
to very fine-grained sandy strata. Methane gas accumulation
and original pore space large enough to occur within host
sediments may be required for forming highly saturated
gas hydrate in pore system. The distribution of a porous
and coarser-grained host rock should be one of the important
factors to control the occurrence of gas hydrate, as well
as physicochemical conditions. Subsequent analyses in
sedimentology and geochemistry performed on gas hydrate-bearing
sandy core samples also revealed important geologic and
sedimentological controls on the formation and concentration
of natural gas hydrate. This appears to be a similar mode
for conventional oil and gas accumulations. It is necessary
for investigating subsurface fluid flow behaviors to evaluate
both porosity and permeability of gas hydrate-bearing
sandy sediments, and the measurements of water permeability
for them indicate that highly saturated sands may have
permeability of a few millidarcies. The isotopic data
of methane show that hydrocarbon gas contained in gas
hydrate is generated by thermogenic decomposition of kerogen
in deep mature sediments. Based on geochemical and geological
data, methane is inferred to migrate upward closely associated
with pore water hundreds of meters into and through the
hydrate stability zone partly up to the permafrost zone
and the surface along faults and permeable sandy pathways.
It should be remarked that there are many similar features
in appearance and characteristics between the terrestrial
and deep marine areas such as Nankai Trough with observations
of well-interconnected and highly saturated pore-space
hydrate. |
|
|
11063
|
Development of a Highly-Active DME Steam Reforming Catalyst
|
Fuel Cell Seminar 2005
2005/11/15 |
Tetsuya Takemoto(Osaka Gas Co., Ltd.), Kengo Tsukahara(Mitsubishi
Gas Chemical Co., Inc.), Naohiko Matsuda(Mitsubishi Heavy
Industries, Ltd.), Hiroshi Hashimoto(JGC Corporation),
Osamu Okada(Renaissance Energy Research Corporation),
Shinichi Suzuki(Japan Oil, Gas and Metals National Corporation)
|
Research Project Team on Emerging Gas Technologies
|
[Abstract] Dimethyl ether (hereinafter referred
to as “DME”) is a promising synthetic fuel with high chemical
stability, extremely low toxicity and physical properties
similar to liquefied petroleum gas. DME can also be a
favorable energy carrier enabling effective utilization
of small and medium-scale gas fields untapped due to economic
constraints, such as high transport costs. To take advantage
of these excellent characteristics, extensive efforts
have been made to develop and improve DME synthesis and
utilization techniques. Focusing our attention on DME
for fuel cell use, we have been developing a compact and
highly efficient fuel cell system using DME as a fuel.
We have been developing (1) DME steam reforming catalysts
with high activity and selectivity, (2) a highly efficient
heat removal system of a CO removal reactor, and (3) a
total fuel cell system. The DME steam reforming reaction
is generally expressed by Eq. (1). The process proceeds
through a sequence of two reactions as follows. The first
reaction is the hydrolysis of DME to methanol as expressed
by Eq. (2) and the second is the steam reforming of methanol
to carbon dioxide and hydrogen as expressed by Eq. (3).
Carbon monoxide is generated by the reverse water-gas
shift reaction (WGSR) as expressed by Eq. (4).
DME steam reforming CH3OCH3 + 3H2O =6H2 + 2CO2 -123.84kJ/mol
(1)
DME Hydrolysis CH3OCH3 + H2O =2CH3OH -24.68kJ/mol (2)
Methanol steam reforming CH3OH + H2O =3H2 + CO2 -49.58kJ/mol
(3)
Reverse WGSR CO2 + H2 = CO + H2O -41.17 kJ/mol (4)
We have developed a highly-active DME steam reforming
catalyst with high activities of DME hydrolysis and methanol
steam reforming. The addition of a certain kind of alumina
to a Cu-Zn catalyst improved the steam reforming performance
of DME. |
|
|
11062
|
Development of Low-temperature DME Steam Reforming System
for Fuel-cell Vehicles
|
Fuel Cell Seminar 2005
2005/11/15 |
Naohiko Matsuda(Mitsubishi Heavy Industries, Ltd.),
Hiroshi Hashimoto(JGC Corporation), Osamu Okada(Renaissance
Energy Research Corporation), Tetsuya Takemoto(Osaka Gas
Co., Ltd.), Kengo Tsukahara(Mitsubishi Gas Chemical Co.,
Inc.), Shinichi Suzuki(Japan Oil, Gas and Metals National
Corporation)
|
Research Project Team on Emerging Gas Technologies
|
[Abstract] DME, Dimethyl Ether is one type
of effective fuel for producing hydrogen because of its
non-sulfur, low reforming temperature and non-toxicity.
Fig.1 shows the characteristic features of DME in a fuel
processor with other fuels. Japan Oil, Gas and Metals
National Corporation has launched a program to develop
an on-board reforming system with optimized performance
characteristics (volume, weight and efficiency) starting
in FY2003, to FY2006. Other projects before this program
developed DME reforming catalysts with low temperature
activity. Using these catalysts, we have improved two
types of fuel processors, an autothermal type equal to
30kWe and an external-heating type equal to 5kWe. Fig.2
shows the schematics for these fuel processors.
Simultaneously, we have researched superiority of the
DME reforming system in comparison with other vehicular
hydrogen storage systems in the aspect of weight, size
and efficiency. |
|
|
11056
|
Seal Materials for Dimethylether (DME) and Liquefied
Petroleum Gas (LPG)
|
International Rubber Conference 2005 YOKOHAMA
2005/10/24-28 |
Kinro Hashimoto, Kazuo Nishimoto, Takumi Arisawa(Nichias
Corporation), Mitsuo Namba, Takeshi Kondo(The High Pressure
Gas Safety Institute of Japan)
|
Research Project Team on Emerging Gas Technologies
|
| [Abstract] DME is the simplest ether without carbon-carbon bonds
in its molecule and does not include any sulfur compounds.
Therefore, DME is expected to spread as a sootless fuel.
As the physical properties of DME resemble to those of
LPG, DME can be used with the facilities of LPG. However,
the chemical properties of DME are different from those
of LPG. So, it is necessary to investigate the possibility
of actual use of various seal materials in DME. Rubbers
and plastics were individually immersed in DME and LPG,
and their volume changes, compression sets and leak rates
were measured. Polytetrafluoroethylene (PTFE), compressed
sheet gaskets and perfluoro elastomer (FFKM) are promising
against both DME and LPG. However, butyl rubber (IIR),
nitrile rubber (NBR), and other elastic materials are
necessary to be evaluated in both DME and LPG before using. |
|
|
11055
|
Hydrogen Production with Steam Reforming of Dimethyl
Ether
|
15th International Symposium on Fine Chemistry and Functional
Polymers (FCFP-XV) & IUPAC 1st International Symposium
on Novel Materials and Synthesis (NMS-I)
2005/10/18 |
Kaoru Takeishi, Akane Arase(Shizuoka University)
|
Research Project Team on Emerging Gas Technologies
|
| [Abstract] Steam reforming of methanol and gasoline is actively
researched as hydrogen supply methods for fuel cells of
vehicles, and so on. However, these materials have problems
such as the infrastructure, toxicity, difficulty of reforming,
and so forth. Dimethyl ether (DME) is expected as one
of clean fuels, and DME is one of substitutes of diesel
fuels and LPG. Infrastructures of LPG will be able to
use for DME. Therefore, we have been studying on DME steam
reforming for hydrogen production. Copper alumina catalysts
prepared by a sol-gel method produced large quantities
of H2 and CO2 with DME steam reforming at 300 ℃. Other
metal alumina catalysts prepared by the sol-gel method
produced H2 and CO2, but also produced large quantities
of CO. Our studies showed that copper is the best metal
for the production of H2 while producing less CO. Á-alumina
for DME hydrolysis into methanol, and copper for methanol
steam reforming to H2 and CO2 coexist on the surfaces
of catalysts prepared by the sol-gel method, and the catalysts
produce more H2 from DME than impregnation catalysts,
mixed catalysts, and so on. We have developed a great
potential for H2 supply from DME. |
|
|
11048
|
Hydrogeology of Methane and Pore Water Accumulation
in Sandy Sediments: Implications for Forming Highly-Saturated
Gas Hydrate in Pore System
|
2005 GSA (Geological Society of America)
2005/10/16-19 |
Takashi Uchida, Amane Waseda(Japan Petroleum Exploration
Co., Ltd.), Takatoshi Namikawa(Japan Oil, Gas and Metals
National Corporation)
|
Methane Hydrate Research Project Team
|
[Abstract] Plenty of gas hydrate-bearing
sand core samples have been obtained from the Mallik wells
at Mackenzie Delta as well as the Nankai Trough wells.
The chloride content anomalies in extracted pore waters,
core temperature depression, core observations, visible
gas hydrates as well as continuous downhole well log data
confirm the presence of pore-space hydrate as intergranular
pore filling within moderate to thick sand layers, which
clarified the characteristics of subsurface natural gas
hydrate beneath the deep sea floor and the permafrost
zone. It should be ramarked that there are many similarities
in appearance and occurrence between the Mallik and Nankai
Trough areas with observations of well-interconnected
and highly saturated pore-space hydrate within sandy sediments.
According to grain size distributions of host sediments
gas hydrates are dominantly contained in medium- to very
fine-grained sandy strata, whose hydrate saturations are
evaluated up to 80 % in pore volume throughout most hydrate-dominant
sand layers, and concentrations of gas hydrate may need
gas accumulation and original pore space large enough
to occur within host sediments. Supplying methane for
deep marine gas hydrate is commonly attributed to microbial
conversion of organic material within the zone of stability
or to migration of methane-containing fluids from a deeper
source area to the gas hydrate stability zone, which should
be closely associated with pore water flow through faults/fractures
and in intergranular pore system of sediments. The distribution
of porous and coarser-grained host sediments should be
one of the important factors to control the occurrence
of gas hydrate, as well as physicochemical conditions.
This appears to be a similar mode for conventional oil
and gas accumulations, and it is necessary for evaluating
subsurface fluid flow behaviors to know both of porosity
and water permeability of gas hydrate-bearing sediments.
Subsequent analyses in sedimentology and geochemistry
performed on gas hydrate-bearing sandy core samples also
revealed important geologic and sedimentological controls
on the formation and preservation of natural gas hydrate.
These knowledge and information are crucial to predicting
the location of other hydrate deposits and their eventual
energy resource. |
|
|
11043
|
PORE-SPACE RECONSTRUCTION OF ROCKS USING MULTIPLE-POINT
STATICS
|
11th Formation Evaluation Symposium of Japan
2005/10/6 |
Hiroshi Okabe(Japan Oil, Gas and Metals National Corporation)
|
Petroleum Engineering Research Team
|
[Abstract] Pore-scale network modeling can
predict multiphase flow properties with arbitrary wetting
conditions if the network represents the geology of the
sample accurately. Such pore-scale modeling uses topologically
disordered networks that realistically represent the pore
structure. To generate the network it is first necessary
to have a three-dimensional voxel-based pore-space representation
that is constructed by either a direct imaging technique
such as micro-CT scanning, stochastic methods, or object-based
approaches.
Multiple-point statistics (MPS) on a two-dimensional (2D)
thin section image are used to generate a three-dimensional
(3D) pore space image with an assumption of isotropy for
orthogonal planes. The method gives images that preserve
typical patterns of the void space seen in thin section.
Using only single and two-point statistics in the reconstruction
often underestimates the void connectivity, especially
for low porosity materials; however, multiple-point statistics
method significantly improves the void connectivity. The
method is tested on sandstone and carbonate samples. Permeability
is predicted directly on the 3D images using the lattice
Boltzmann method (LBM). The numerically estimated results
are in good agreement with experimentally measured permeability.
Furthermore, the method provides an important input for
the creation of geologically realistic networks for pore-scale
modeling to predict multiphase flow properties. |
|
|
11041
|
Application of Wireline Conveyed Through Casing Formation
Tester to Methane Hydrate Research in Japan
|
11th Formation Evaluation Symposium of Japan
2005/10/5-6 |
Koji Yamamoto, Masato Yasuda, Masaru Nakamizu(Japan
Oil, Gas and Metals National Corporation), Khong Chee
Kin(Schlumberger Oilfield Services, China), Koji Kusaka(Schlumberger
Oilfield Services, Nagaoka, Japan)
|
Methane Hydrate Research Project Team
|
[Abstract] Several countries are eagerly
examining methane hydrate as a next-generation energy
resource. Among them, governmental and private sectors
of Japan have launched the Research Consortium for Methane
Hydrate Resources in Japan (MH21) for the methane hydrate
resource study in marine sediments.
Effective exploitation of methane hydrate resources requires
an understanding of the mechanical earth model. Geomechanical
data such as in-situ stresses and rock strengths are important
to a wide range of applications. At present, the only
reliable, accurate measurements of in-situ stress come
from induced micro-fracturing experiments. These data
are obtained using openhole wireline-conveyed formation
testers, but this method is not suitable for unconsolidated
methane hydrate reservoirs that degrade when borehole
temperature rise.
Japan Oil, Gas and Metals National Corporation (JOGMEC)
drilled about 30 wells in an early-2004 research drilling
campaign in the Nankai Trough area in southeastern Japan.
The main objectives of this campaign were to evaluate
resource potential in the area and to understand various
properties related to methane hydrate. In the campaign,
JOGMEC created a team that included oil company, drilling
contractor, and service company engineers to evaluate
the best options to acquire these important geomechanical
data.
An innovative wireline-conveyed throughcasing formation
tester was proposed. The tool seals against the casing
and uses a flexible drill shaft to penetrate through the
casing and the cement into the formation. It is capable
of measuring multiple pressures and sampling fluid in
a single trip. The tool can also be configured to pump
wellbore fluid into the formation for microfracturing
experiments.
The tool was used successfully to acquire reservoir pressure,
mobility, and minimum stress data at the methane hydrate
zone of a cased deepwater well. In this paper, the prejob
planning and modeling process as well as the test results
will be presented. |
|
|
11040
|
Current status of DME - reforming system for PEFC and
Comparison of hydrogen supply methods for Fuel Cell Vehicles
|
9th Grove Fuel Cell Symposium
2005/10/5 |
Osamu Okada(Renaissance Energy Research Corporation),
Tetsuya Takemoto(Osaka Gas Co., Ltd.), Kengo Tsukahara(Mitsubishi
Gas Chemical Co., Inc.), Hiroshi Hashimoto(JGC Corporation),
Naohiko Matsuda(Mitsubishi Heavy Industries, Ltd.), Shinichi
Suzuki(Japan Oil, Gas and Metals National Corporation)
|
Research Project Team on Emerging Gas Technologies
|
[Abstract] DME is a promising synthetic
fuel from Natural Gas. So, extensive efforts have been
made to develop and improve DME manufacturing techniques,
and develop application technologies to promote the use
of DME. Focusing our attention on DME, which is expected
to offer extensive applications, we are developing a compact
and high-efficiency reforming system for PEFC that uses
DME as a fuel. To this end, our efforts have been focused
on the development of a DME reforming unit, and the downsizing
and improved efficiency of existing reforming systems.
We have been conducting research and development on: 1)
a DME reforming catalyst, 2) a comprehensive DME reforming
system.
Based on result of such R&D activities, we started
development of advanced DME- reforming system for automobile.
This presentation reports the present status of the development.
To accelerate wider commercialization of Fuel Cell Vehicles(FCV),
it is very important to develop practical on-board hydrogen
supply methods for FCV.
So, we compared total volume, total weight and total energy
efficiency of various hydrogen supply systems for FCV.
In the compression hydrogen method, it is difficult to
extend the mileage at present pressure (35MPa) from the
limit on the size, and total energy efficiency decreases
at higher compression pressure (70MPa). In the metal hydride
(MH) tank method, hydrogen storage rate per weight is
small and the weight of metal hydride only is 200kg (3%
MH). And improvement of hydrogen storage density does
not always make total size compact, because larger heat
transfer area is needed when reaction heat is larger.
On the other hand, DME reforming method is advantageous
in total energy efficiency and total size of it is also
small. Though start-up time is slow, DME reforming method
seems to be the most suitable for hydrogen supply system
for FCV, when FCV total system including reforming system
is optimized. |
|
|
11039
|
Geochemistry of gas hydrate in the Nankai Trough, Japan
|
8th International Conference on Gas Geochemistry
2005/10/2-8 |
Amane Waseda, Takashi Uchida(Japan Petroleum Exploration
Co., Ltd.), Takatoshi Namikawa(Japan Oil, Gas and Metals
National Corporation)
|
Methane Hydrate Research Project Team
|
[Abstract] In 2004, multiple shallow drillings
for gas hydrate exploration were conducted in the eastern
Nankai Trough, offshore central Japan. Gas hydrate-bearing
sediments were recovered from three sites. Prior to the
drillings, a 2355 mbsf (m below seafloor) deep well (MITI
Nankai Trough) was drilled for gas hydrates and conventional
oil and gas exploration in late 1999-early 2000.
Carbon and hydrogen isotope compositions of methane and
hydrocarbon compositions in gas hydrates and gas hydrate-bearing
shallow sediments were measured to investigate the origin
of the gas in hydrates. In two sites, the gas molecular
and isotopic data suggest that the methane is generated
by microbial reduction of CO2 with no contribution of
thermogenic hydrocarbons. On the other hand, minor contribution
of thermogenic methane is recognized at one site located
near mud volcanoes based on the heavier carbon isotope
compositions of methane.
The measured TOC (total organic carbon) in the Nankai
Trough is around 0.5%, which is considered too low for
in situ formation of gas hydrate. However, geophysical
and geochemical data suggest that the saturation of gas
hydrate in pore space in the hydrate-bearing sediments
is high, up to 80%. Consequently, some gas migration and
accumulation processes are required for the concentrated
formation of the gas hydrates in the Nankai Trough. This
process may be related to the geological setting of the
Nankai Trough, where fluid flow containing methane is
active through thrust systems within Nankai accretionary
prism sediments. The sediments are composed mainly of
sand and shale layers and gas hydrates are concentrated
only in sand layers, suggesting that the gas migrated
and accumulated selectively to permeable sand layers.
Little or no indication of thermogenic gases in shallow
sediment including the hydrate-bearing intervals suggests
that the fluid migration is rather local and restricted
to the shallow sediments. However, the existence of the
thermogenic gases in deep sediments confirmed in the deep
MITI well suggests that gas hydrates of thermogenic origin
could form in some areas where permeable conduits such
as large fault systems develop in the sediments.
This study was performed as a part of the Research Consortium
for Methane Hydrate Resources in Japan. |
|
|
11038
|
Current Status of R&D for the DME Utilization Technologies
by the JOGMEC Programs
|
2nd Asian DME Conference
2005/9/19 |
Shinichi Suzuki(Japan Oil, Gas and Metals National Corporation)
|
Research Project Team on Emerging Gas Technologies
|
[Abstract] Japanese private companies have
been developing DME Utilization Technologies such equipment
as turbines for power plants, diesel engines for distributed
power generation and vehicles, and reforming equipment
to produce methane for SNG (Substitute Natural Gas) and
hydrogen for PEFC under the program of Japan Oil, Gas
and Metals Corporation (JOGMEC)fs Technology-Developing
Scheme.
In the coming few years, various DME utilization technologies
will be feasible for practical use thanks to the vigorous
efforts currently rendered by the various Japanese organizations.
Keyword: Dimethyl Ether, utilization technologies, power
generation, gas turbine, boiler, diesel engine, diesel
vehicle, substitute natural gas, fuel cell |
|
|
11033
|
OCEAN BOTTOM SEISMOMETER WIDE-ANGLE REFLECTION STUDY
OF GAS HYDRATE ACCUMULATIONS IN NANKAI TROUGH, OFFSHORE
TOKAI, JAPAN
|
AAPG International Conference and Exhibition 2005
2005/9/11-14 |
Eiichi Asakawa, Peter Ward(JGI Inc.), Maarten Vanneste, Stephanie
Guidard, Juergen Mienert(University of Tromso, Norway),
Tatsuo Saeki(Japan Oil, Gas and Metals National Corporation)
|
Methane Hydrate Research Project Team
|
[Abstract] In 1996 and 1997, 4-component
ocean bottom seismometer (OBS) data were acquired in the
Nankai Trough, offshore Tokai, Japan. We analyzed these
data in combination with multi-channel seismic (MCS) data
to study the distribution and characteristics of methane
hydrates in the sediments. The seismic data reveals a
very complex and dynamic sedimentation history, dominated
by dipping turbidite deposits, active channels, folds,
and high-angle faults. Despite this, the bottom-simulating
reflection (BSR), indicative for the presence of gas hydrates,
is easily recognized as a laterally-variable amplitude
reflection.
We applied an imaging technique to the OBS reflection
data and obtained results that have good agreement with
the MCS section. We also applied modeling and inversion
procedures to reveal the detailed velocity structure.
The OBS data allowed us to construct a 9 layer geophysical
model for the uppermost 700 m of sediments in the eastern
Nankai Trough, in water depths of 930 to 1160 m. Travel-time
inversion gives elevated P-wave velocities, reaching values
of up 2100 m/s. Such high P-wave velocities can be explained
by a partial hydrate saturation of pore space of up to
20%. The BSR at `320 mbsf coincides with a significant
drop in P-wave velocity to values between 1580 and 1750
m/s. This lower-velocity layer is `80 m thick.
The S-wave velocities were subsequently derived by event
correlation, time picking and forward modeling of the
wide-angle data, and are up to 700-750 m/s in the hydrate
zone. We observe a small decrease of S-wave velocity underneath
the BSR. This might indicate a weak hydrate cementation
of the sedimentary matrix. In the deeper section however,
the high P- and S-wave velocities indicate over-consolidated
sediments, attributed to the particular compressional
tectonic setting. |
|
|
11029
|
BRIDGING PORE TO CORE-SCALE FLOW PROPERTIES USING PORE-SCALE
MODELING AND COREFLOOD SIMULATION
|
International Symposium of the Society of Core Analysis
2005/8/24 |
Hiroshi Okabe(Japan Oil, Gas and Metals National Corporation, Imperial
College London)
|
Petroleum Engineering Research Team
|
[Abstract] Simulating a coreflood experiment
is more than a good exercise. It is the only way to deduce
flow properties of a heterogeneous rock or when the capillary
effects are important. Numerical simulation is very often
a better approach than the traditional method such as
JBN, especially for heterogeneous rock samples, to understand
detailed flow behavior. Since many parameters are involved
during history matching of the experiment, the matching
process becomes more complicated as the core-scale heterogeneity
is increased. In order to optimize matching parameters
efficiently, an automated history-matching program using
the Genetic Algorithm has been developed. The program
is used to interpret coreflood displacements on heterogeneous
carbonate cores and successfully predicts a reasonable
set of relative permeability and capillary pressure curves
within given pore-types, which are the representative
classes of void structures of the rock. Although the program
numerically estimates flow properties for each pore-type,
it is better if these properties are explained using pore-scale
modeling, which supports these flow properties derived
by the coreflood simulation.
Core-scale heterogeneity is assigned by the key pore-types
that are characterized by petrographical and petrophysical
analysis. Pore-scale modeling simulates multiphase flow
through each pore-type. Predicted flow properties using
pore-scale modeling are consistent with those derived
by the coreflood simulation using the Genetic Algorithm.
The combination of pore and core-scale analyses improves
the understanding of flow through heterogeneous porous
media and the method bridges pore to core-scale analysis.
|
|
|
11027
|
Climate-controlled stratigraphic correlations and sedimentary
facies variability of fluvial reservoirs- from outcrop
to subsurface
|
8th International Conference on Fluvial Sedimentology
2005/8/7-12 |
Swie Djin Nio, M. De Jong (ENRES International), D.
Smith(ENRES UK), Osamu Takano(Japan Oil, Gas and Metals
National Corporation)
|
Geology & Geophysics Research Team
|
[Abstract] One of the main problems in alluvial-fluvial
reservoirs is the construction of a detailed time-related
stratigraphic correlation. Such a high-resolution stratigraphic
framework is essential to understand the relationship
between the different reservoir unit and subsequent reservoir
modelling. The problem is mainly caused by the absence
of good biostratigraphic information. Other stratigraphic
methods, such as chemostratigraphy are often constraint
by problems in resolution.
An alternative correlation technique is to use periodic
climatic changes as the main controlling mechanism in
stratigraphic variation through space and time. The premise
is that periodic climatic changes contribute to the variance
in most (if not all) sedimentary strata. Alluvial-fluvial
facies associations are especially very sensitive to climatic
changes. Exploitation of this information for the subsurface
requires the use of frequency-based method of analysis,
such as spectral analysis of facies-sensitive wireline
logs. A specially designed algorithm is able to calculate
attributes from the spectral analysis of log data, showing
the cyclic (or periodic) succession of the different stratigraphic
packages and the frequency content which shows the depositional
trends in time. The calculations generate a curve which
is defined as the Spectral Trend Attribute or INPEFA curve.
INPEFA curves from the Upper Carboniferous of the Southern
North Sea show a consistent pattern of a cyclic pattern
of fluvial channel belts and floodbasin fines. It also
shows distinct depositional patterns and the log data
also indicate a variance in alluvial-fluvial facies.
With this information, outcrop analogues were studied
for evaluating the relationship between climatic changes
and alluvial-fluvial facies variability.
Specially selected areas in the Eocene Southern Pyrenees
foreland basin were studied in detail and climate-related
alluvial-fluvial depositional facies models were constructed.
Briefly, these models consist of alluvial-fluvial “cycles”
which can be differentiated into three stages representing
rising base levels due to progressively increasing humidity:
1. The entrenchment stage (relatively low humidity and
low base level); a basal erosional channel is formed,
later filled by coarse clastics and generally representing
straight or very low sinuous channels
2. The expansion stage (rising humidity and higher base
level); formation of a laterally extensive channel sandbody,
generally representing low-sinuous sandy braided channels.
Periodic avulsions cause shifting of the channels and
hence a lateral dispersion of the sand.
3. The confinement stage (high humidity and high base
levels): formation of mixed-load high-sinuous channels
in a single meandering river or a meander belt.
By applying this information to the subsurface, a detailed
near-synchronous stratigraphic framework can be constructed
together with the alluvial-fluvial facies variations in
time.
The example from the Upper Carboniferous of the Chiswick
Field shows such a detailed reservoir correlation and
also give information on reservoir quality. |
|
|
11014
|
Velocity Structure of the Kumano Basin in the Nankai
Trough
|
5th International Conference on Gas Hydrates
2005/6/13-16 |
Tatsuo Saeki, Masao Hayashi, Takao Inamori, Osamu Takano(Japan
Oil, Gas and Metals National Corporation), Jun Matsushima
, Sumito Morita(National institute of Advanced Industrial
Science and technology, AIST)
|
Methane Hydrate Research Project Team
|
[Abstract] BSR (bottom simulating reflector)
is considered as a bottom of methane hydrate bearing sediments,
commonly thought to have free gas layers below. Therefore,
BSR interpretation on reflection seismic profiles has
been used for delineation of horizontal distributions
of methane hydrate layers and their base structures. On
the other hand, velocity structure analysis using seismic
data is also expected to provide additional knowledge
(vertical distributions of methane hydrate layer, concentration
rate etc.), because the P-wave velocity of methane hydrates
is higher than that of surrounding sediments.
The velocity structure of the Kumano basin in the eastern
Nankai Trough was analyzed using seismic data. In the
portion of the survey area, only 2D seismic data was available.
Because of complex geological structure in the survey
area and large feathering angle occurrence in the data
acquisition, 2D conventional seismic velocity analysis
produced a considerable amount of artificial high and
low velocity anomalies. Against the above problem, the
pseudo-3D diffraction stacking method with multi 2D lines
data was applied successfully for the velocity analysis.
Results based on both of BSR interpretation and velocity
analysis suggested that methane hydrate distributions
in the Kumano basin might be under the control of some
geological settings. |
|
|
11013
|
Ocean Bottom Seismometer Wide-Angle Reflection Study
of Gas Hydrate Accumulations in Nankai Trough, Offshore
Tokai, Japan
|
5th International Conference on Gas Hydrates
2005/6/13-16 |
Eiichi Asakawa, Peter Ward(JGI Inc.), Maarten Vanneste, Stephanie
Guidard, Juergen Mienert(University of Tromso, Norway),
Tatsuo Saeki(Japan Oil, Gas and Metals National Corporation)
|
Methane Hydrate Research Project Team
|
[Abstract] In 1996 and 1997, 4-component
ocean bottom seismometer (OBS) data were acquired in the
Nankai Trough, offshore Tokai, Japan. We analyzed these
data in combination with multi-channel seismic (MCS) data
to study the distribution and characteristics of methane
hydrates in the sediments. The seismic data reveals a
very complex and dynamic sedimentation history, dominated
by dipping turbidite deposits, active channels, folds,
and high-angle faults. Despite this, the bottom-simulating
reflection (BSR), indicative for the presence of gas hydrates,
is easily recognized as a laterally-variable amplitude
reflection.
We applied an imaging technique to the OBS reflection
data and obtained results that have good agreement with
the MCS section. We also applied modeling and inversion
procedures to reveal the detailed velocity structure.
The OBS data allowed us to construct a 9 layer geophysical
model for the uppermost 700 m of sediments in the eastern
Nankai Trough, in water depths of 930 to 1160 m. Travel-time
inversion gives elevated P-wave velocities, reaching values
of up 2100 m/s. Such high P-wave velocities can be explained
by a partial hydrate saturation of pore space of up to
20%. The BSR at `320 mbsf coincides with a significant
drop in P-wave velocity to values between 1580 and 1750
m/s. This lower-velocity layer is `80 m thick.
The S-wave velocities were subsequently derived by event
correlation, time picking and forward modeling of the
wide-angle data, and are up to 700-750 m/s in the hydrate
zone. We observe a small decrease of S-wave velocity underneath
the BSR. This might indicate a weak hydrate cementation
of the sedimentary matrix. In the deeper section however,
the high P- and S-wave velocities indicate over-consolidated
sediments, attributed to the particular compressional
tectonic setting. |
|
|
11012
|
Case Study of Cross-Dipole Sonic Anisotropy and Dispersion
Analysis in a Gas Hydrate Resevoir
|
5th International Conference on Gas Hydrates
2005/6/13-17 |
Doug Murray, Osamu Osawa, Bikash Sinha(Schlumberger),
Koji Yamamoto(Japan Oil, Gas and Metals National Corporation)
|
Methane Hydrate Research Project Team
|
[Abstract] The acquisition of cross dipole
borehole sonic waveform data has become an established
practice for the identification of acoustic anisotropy
in conventional oil and gas reservoirs. Recent advances
in the interpretation of dipole shear slownesses and their
dispersive characteristics (frequency vs. slowness) have
been used to improve the understanding of the types of
acoustic anisotropy (intrinsic or stress-induced), identify
zones of near-wellbore alteration and to make estimates
of the geomechanical horizontal stresses.
The use of the latest borehole sonic acquisition and interpretation
techniques is of importance to the evaluation and potential
development of gas hydrate reservoirs, which by their
nature, are often found in shallow, unconsolidated offshore
sediments.
This paper presents a review of the dispersion analysis
technique and its related answer products with a special
emphasis on its application to gas hydrate reservoirs.
It clearly identifies zones of near-wellbore alteration,
acoustic anisotropy and is a key component in the estimation
of the geomechanical horizontal stresses, a good understanding
of which are an important requirement for well placement,
well completion and fluid production. The paper also highlights
some of the interesting features of borehole sonic logs
acquired in gas hydrate reservoirs and contrasts this
with the acoustic responses of surrounding non-hydrate
bearing rocks. |
|
|
11011
|
Geomechanical Condition of Deep Water Unconsolidated
and Hydrate Related Sediments off the Pacific Coast of
Central Japan
|
5th International Conference on Gas Hydrates
2005/6/13-17 |
Koji Yamamoto, Masato Yasuda(Japan Oil, Gas and Metals
National Corporation), Osamu Osawa(Schlumberger)
|
Methane Hydrate Research Project Team
|
| [Abstract] During the MITI Nankai-trough (1999-2000) and METI Tokai-oki
to Kumano-nada (2004) drilling campaigns, much geomechanical
information was obtained. Well log data such as compressional
and shear sonic velocity, resistivity images and wireline
pressure tests as well as core samples of the hydrate
and non-hydrate bearing shallow, unconsolidated formations
were obtained. Petroleum geomechanics analytical methods
were applied to the data, much geomechanical information
like field formation stresses were obtained. Some of those
data show the unique feature of the hydrate related sediments.
Furthermore, those data are valuable for the future safe
and effective hydrate resource development. |
|
|
11010
|
Active Downhole Thermal Property Measurement System
for Characterization of Gas Hydrate Bearing Formations
|
5th International Conference on Gas Hydrates
2005/6/13-16 |
Masafumi Fukuhara, Kasumi Fujii, Vladimir Tertychnyi,
Alexander Shandrygin(Schlumberger), Yuri Popov(MSGPU),
Osamu Matsubayashi(National Institute of Advanced Industrial
Science and Technology, AIST), Koji Kusaka, Masato Yasuda(Japan
Oil, Gas and Metals National Corporation)
|
Methane Hydrate Research Project Team
|
[Abstract] Gas hydrates dissociate or form
when temperature and/or pressure conditions cross the
equilibrium border. When we consider gas hydrates as an
energy resource, understanding those parameters is very
important for developing efficient production schemes.
Therefore, thermal measurement is one of the key components
of the characterization of the gas hydrate-bearing formation-not
only statistically but also dynamically.
To estimate thermal properties such as thermal conductivity
and diffusivity of subsurface formations, the conventional
method has been to monitor temperature passively at several
underground locations and interpret collected information
with assumptions such as steady heat flow or relaxation
from thermal disturbance by fluid flow, etc. Because the
thermal properties are estimated based on several assumptions,
these passive measurement methods sometimes leave a lot
of uncertainties. On the other hand, active thermal property
measurement, which could minimize those uncertainties,
is commonly used in a laboratory and many types of equipment
exist commercially. The concept of measurement is very
simple: creating a known thermal disturbance with a thermal
source and then monitoring the response of the specimen.
However, simply applying this method to subsurface formation
measurement has a lot of technical and logistical difficulties.
In this paper, newly developed active subsurface thermal
property measurement equipment and its measurement methodology
are described. Also discussed are the theoretical background
for the application of the methodology to a gas hydrate-bearing
formation through numerical simulation and the experimental
results of laboratory mockup in a controlled environment. |
|
|
11009
|
Delineation of gas hydrate-bearing sediments by multi
seismic attributes using 3D seismic survey, offshore Tokai,
Japan
|
5th International Conference on Gas Hydrates
2005/6/13-16 |
Takao Inamori(Japan Oil, Gas and Metals National Corporation),
Masami Hato(JGI, Inc.), Tatsuo Saeki(Japan Oil, Gas and
Metals National Corporation)
|
Methane Hydrate Research Project Team
|
| [Abstract] In order to estimate the amount of gas hydrate accurately,
we have to get the more detailed reservoir parameters
such as the gas hydrate saturation, the porosity or the
thickness of the gas hydrate reservoir layer. We found
the relationship between the gas hydrate and P-wave interval
velocity from the NMO velocity analysis and P-wave impedance,
S-wave impedance, pseudo Poisson's ratio, attenuation
of seismic wave from the seismic attributes analysis using
the 3D seismic survey data. We applied the hybrid method
and KSOM (Kohonen Self-Organizing Map) method to integrate
seismic attribute results. We compared hybrid and KSOM
results with borehole logging data. We found good correlations
between integrated seismic attributes such as a hybrid
attribute and KSOM attributes, and the range of hydrate-bearing
sediments estimated from logging data. We delineated the
extension of gas hydrate-bearing sediments, offshore Tokai,
Japan by the seismic attributes analysis. |
|
|
11008
|
Modes of occurrence and accumulation mechanism of methane
hydrate in the Nankai Trough, southern offshore Japan
-Result of METI exploratory test wells “Tokai-oki to Kumano-nada-”
|
5th International Conference on Gas Hydrates
2005/6/13-16 |
Tetsuya Fujii, Takatoshi Namikawa, Masaru Nakamizu,
Yoshihiro Tsuji (Japan Oil, Gas and Metals National Corporation),
Toshiharu Okui (Tokyo Gas Co., Ltd.), Masayuki Kawasaki
(Japan Drilling Co., Ltd.), Koji Ochiai (Japan Oil, Gas
and Metals National Corporation (presently INPEX Corporation)
)
|
Methane Hydrate Research Project Team
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[Abstract] In the Nankai Trough, southern
offshore Japan, seismic data indicates widespread existence
of BSR, which is interpreted as an indicator of bottom
boundary of methane hydrate bearing zone. Methane hydrate
is regarded as future possible natural gas resource, although
the modes of its occurrence and distribution have not
been poorly understood. In order to obtain data for the
understanding of methane hydrate occurrence and natural
reserves estimation, METI exploratory test wells efTokai-oki
to Kumano-nada” were drilled from January to May in 2004.
As a first step, LWD (Logging While Drilling) was carried
out at 16 sites that were selected based on 2D and 3D
seismic interpretation. Secondly, coring was carried out
at 4 sites where high concentration of methane hydrate
was expected based on resistivity log curve. In addition,
continuous formation temperature measurement was carried
out in order to investigate in-situ temperature condition
in hydrate bearing sediments. Coring was carried out using
both ODP type core sampler and PTCS (Pressure Temperature
Core Sampler). PTCS coring were mainly focused on the
hydrate bearing zone.
Hydrate was confirmed in the pore space of turbidity
sandstone layer in two of these sites, while it was confirmed
as nodules in mudstone layer in others. Coring results
suggest that most of hydrate were concentrated in relatively
thick sandstone layers in the alternation of sand and
clay. The evidence may indicates permeable sandstone is
ideal for hydrate accumulation. Hydrate decomposition
and gas measurement test on board was also carried out
and natural hydrate saturation data, which may calibrate
logging results, was obtained.
These observations will be integrated with the numerical
simulation, and accumulation mechanism of gas hydrate
in the Nankai Trough will be considered. |
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11007
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Thermal Regime Long-Term Monitoring for Marine Gas Hydrate-Bearing
Sediments
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5th International Conference on Gas Hydrates
2005/6/13/16 |
Masafumi Fukuhara, Kasumi Fujii, Juei Igarashi, Vladimir
Tertychnyi, Alexander Shandrygin (Schlumberger), Osamu
Matsubayashi (National Institute of Advanced Industrial
Science and Technology, AIST), Tetsuya Fujii(Japan Oil,
Gas and Metals National Corporation) |
Methane Hydrate Research Project Team
|
[Abstract] Gas hydrates dissociate or form
when temperature and/or pressure conditions cross the
equilibrium border. Therefore, temperature measurement
is one of the key components to evaluate the characteristics
of gas hydrate-bearing sediment.
Using recent technology, a precise in-situ temperature
measurement system was developed and deployed in deep
water offshore Japan. The temperature in hydrate-bearing
sediment was monitored in the deepwater well for 1.5 months.
The primary purpose of the temperature measurement was
to evaluate the thermal regime of marine hydrate-bearing
sediment, seeking such answers as the definition of the
hydrate stability zone, delineations of the geothermal
gradient if it is affected by heterogeneous distribution
of hydrates, and the cause of Double Bottom Simulating
Reflector [1 and 2] if a thermal anomaly exists. In addition,
seasonal seafloor temperature changes relating tidal changes
were observed within the precision of the temperature
measurement range.
Because the measurements were collected over sufficient
duration, the quasi steady-state downhole temperature
after relaxation from drilling and the sensor inclusion
effect on original formation temperature were easily defined
through observation of the dynamic movement. Distinctive
thermal gradient was observed at the hydrate-bearing zone.
The seafloor temperature was affected and correlated by
tidal motion with a few degrees Celsius variation.
Keywords: temperature, long-term monitoring, DTS |
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11006
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What is BSR (Bottom Simulating Reflector)? - A hypothesis
based on the result of multi-well drilling campaign METI
“Tokai-oki to Kumano-nada”
|
5th International Conference on Gas Hydrates
2005/6/13/16 |
Takatoshi Namikawa, Tetsuya Fujii, Masaru Nakamizu,
Yoshihiro Tsuji (Japan Oil, Gas and Metals National Corporation)
|
Methane Hydrate Research Project Team
|
[Abstract] BSR is well known as an indicator
of natural methane hydrate bearing layer below sea floor.
It is considered that acoustic impedance contrast between
hydrate bearing zone and lower unconsolidated sediments
or “Free gas” raise this characteristic seismic reflector.
Japan Oil, Gas and Metals National Corporation (JOGMEC)
have carried out a multi-well drilling campaign METI ”Tokai-oki
to Kumano-nada” from January to May 2004. 16 sites have
drilled to confirm various statuses of hydrate indications,
including “Double BSR”. It is found that BSR doesnft always
indicate an existence of thick methane hydrate concentration
zone. On the other hand, significant wellbore breakout
and acoustic low velocity zone always existed below estimated
hydrate stability zone. Those are correlate to the lower
part of “broad BSR” on seismic section. We have confirmed
the lower BSR is completely below hydrate stability zone.
We need a new interpretation for BSR to explain those
findings.
Major distributions of BSR in Japan are situated in accretion
belt, and it is easy to imagine the sediments was uplifted
intermittently. When sediments include tectonic movement,
lower limit of the methane hydrate stability zone also
move to upward, uplift methane hydrate. The concentrated
methane hydrate is dissociated and looses the sediment
bonding; as a result acoustic low velocity sediments are
remained. Considering those geological setting, a hypothesis
of BSR origin is now proposed although farther discussion
is needed. |
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11005
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Observation of methane hydrate dissociation behavior
in methane hydrate bearing sediments by X-ray CT Scanner
|
5th International Conference on Gas Hydrates
2005/6/13-16 |
Tatsuji Kawasaki, Yoshihiro Tsuchiya, Masaru Nakamizu(Japan
Oil, Gas and Metals National Corporation), Toshiharu Okui(Tokyo-gas
Co., Ltd.)
|
Methane Hydrate Research Project Team
|
[Abstract] The dissociation behaviour of
methane hydrate (MH) in synthetic core samples, composed
of very fine- to fine-grained sand of which MH saturation
is 60%, was experimentally investigated in this study
using X-ray computed tomography (CT scanning) under in-situ
conditions. The dissociation examination was carried out
in a depressurized condition (10 ℃, 6.5 MPa). Laboratory
CT scanning successfully imaged the dissociation behaviour
of MH. It was observed that MH began to dissociate near
the surface of the core immediately after depressurization.
With progress of time, the expansion of the dissociated
gas is observed at middle part of the core and that of
water at both sides of the core.
As the result of the additional water injection at rate
of 0.05 ml/min after the above-mentioned experiment, it
is suggested that the injected water has pushed out dissociated
gas that has been kept within the core to the opposite
side.
Keywords: Methane hydrate, dissociation, X-ray, CT, depressurization,
and water injection |
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11004
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Model based Temperature Measurement System Development
for Marine Methane Hydrate-Bearing Sediments
|
5th International Conference on Gas Hydrates
2005/6/13-16 |
Masafumi Fukuhara, Hitoshi Sugiyama, Juei Igarashi,
Kasumi Fujii, Onodera Shun'etsu, Vladimir Tertychnyi,
Alexander Shandrygin (Schlumberger), Viacheslav Pimenov,
Valery Shako (Moscow State Geological Prospecting University),
Osamu Matsubayashi (National Institute of Advanced Industrial
Science and Technology, AIST), Koji Ochiai (Japan Oil,
Gas and Metals National Corporation (presently INPEX Corporation))
|
Methane Hydrate Research Project Team
|
[Abstract] To understand the detailed profile
of geothermal gradients in marine methane hydrate sediment
and to study double BSR (DBSR), a high-precision temperature
measurement system incorporating three different techniques
was installed in a deepwater well. One of the key techniques
is the distributed temperature sensing system (DTS), which
utilizes Raman band backscattering of fiber optics and
can produce seamless temperature profiling in the entire
hydrate stability zone.
Numerical modeling was performed to validate a thermal
measurement method that considered thermal effects of
the drilling parameters, the vertical spatial smoothing
effect of the temperature profile caused by different
well contents, and temperature relaxation time after drilling.
Based on those modeling results, a sensor placement scheme
and an unconventional deployment method were designed
for the project. All the measurement equipment was packaged
in the pressure housing and placed at the seafloor with
battery operation. The system was deployed offshore Japan
and measured the temperature of methane hydrate sediment
for 50 days.
This paper describes the effect of the sensor installation
on the temperature of the hydrate-bearing sediments through
modeling, how the system was deployed in Nankai Trough
area in Japan, and the features of the marine methane
hydrate temperature measurement system.
Keywords: temperature, measurement system, modeling, DTS |
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11003
|
Formation Evaluation Techniques to Estimate Gas Hydrate
Saturation
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5th International Conference on Gas Hydrates
2005/6/13-16 |
Doug Murray, Osamu Osawa, Robert Kleinberg (Schlumberger),
Takatoshi Namikawa (Japan Oil, Gas and Metals National
Corporation)
|
Methane Hydrate Research Project Team
|
[Abstract] Several formation evaluation
techniques have been developed to evaluate the fluid saturation
of gas hydrate reservoirs. Resistivity, DMR (density-magnetic
resonance) and sonic are the most common techniques. The
resistivity technique is based on the well-known Archie
principles relating porosity and saturation to resistivity;
the DMR technique compares the density porosity to NMR
porosity; and the sonic technique relies on a comparison
of sonic derived porosities with those from other porosity
devices that are relatively unaffected by the presence
of hydrate. While the computed saturations of each technique
often agree and validate the results of the others, there
are occasions where they are inconsistent. On these occasions
the source of the inconsistency can usually be traced
to either an erroneous assumption or to a limitation in
the physics of the underlying measurement. Inconsistencies
are often the source of additional information that improves
the understanding of the reservoir. This paper presents
a review of the various hydrate reservoir saturation techniques,
along with their benefits and limitations, and suggests
an optimal workflow for the estimation of hydrate saturation.
Keywords: gas hydrate, well logging, porosity, saturation |
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11002
|
Concentration of Gas Hydrate in Sandy Sediments: Implications
for Subsurface Occurrence and Methane Accumulation
|
5th International Conference on Gas Hydrates
2005/6/13-16 |
Takashi Uchida, Amane Waseda(Japan Petroleum Exploration
Co., Ltd.), Takatoshi Namikawa(Japan Oil, Gas and Metals
National Corporation)
|
Methane Hydrate Research Project Team
|
[Abstract] Plenty of gas hydrate-bearing
sand core samples have been obtained from the Mallik wells
at Mackenzie Delta as well as the Nankai Trough wells.
The chloride content anomalies in extracted pore waters,
core temperature depression, core observations, visible
gas hydrates as well as continuous downhole well log data
confirm the presence of pore-space hydrates as intergranular
pore filling within moderate to thick sand layers, which
clarified the characteristics of subsurface natural gas
hydrate beneath the deep sea floor and the permafrost
zone. It should be noted that there are many similarities
in appearance and occurrence between the Mallik and Nankai
Trough areas with observations of well-interconnected
and highly saturated pore-space hydrate within sandy sediments.
According to grain size distributions gas hydrates are
dominant in medium- to very fine-grained sandy strata,
whose hydrate saturations are evaluated up to 80 % in
pore volume throughout most hydrate-dominant sand layers,
and concentrations of gas hydrate may need gas accumulation
and original pore space large enough to occur within host
sediments. The distribution of a porous and coarser-grained
host rock should be one of the important factors to control
the occurrence of gas hydrate, as well as physicochemical
conditions. This appears to be a similar mode for conventional
oil and gas accumulations, and it is necessary for evaluating
subsurface fluid flow behaviors to know both of porosity
and water permeability of gas hydrate-bearing sediments.
Subsequent analyses in sedimentology and geochemistry
performed on gas hydrate-bearing sandy core samples also
revealed important geologic and sedimentological controls
on the formation and preservation of natural gas hydrate.
These knowledge and information are crucial to predicting
the location of other hydrate deposits and their eventual
energy resource. |
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11001
|
The Characteristics of Gas Origin and Migration in Marine
and Terrestrial Gas Hydrate Deposits
|
5th International Conference on Gas Hydrates
2005/6/13-16 |
Amane Waseda, Takashi Uchida(Japan Petroleum Exploration
Co., Ltd.), Takatoshi Namikawa(Japan Oil, Gas and Metals
National Corporation)
|
Methane Hydrate Research Project Team
|
| [Abstract] Gas origin and migration in marine gas hydrate-bearing
sediments in the Nankai Trough, and terrestrial gas hydrate-bearing
sediments in the Mackenzie Delta are investigated using
gas molecular and isotopic data. Carbon and hydrogen isotope
compositions of methane and hydrocarbon compositions in
gas hydrates and gas hydrate-bearing shallow sediments
in the Nankai Trough show that the methane is generated
by microbial reduction of CO2, although minor contribution
of thermogenic methane was recognized at one site located
near mud volcanoes. In the Mackenzie Delta, the isotopic
data show that the gas in gas hydrate is generated by
thermogenic decomposition of kerogen. Gas isotope profiles
in the Nankai Trough suggest progressive decrease in microbial
activity with depth and upward gas migration through the
sediment column. Based on the geochemical and geological
data, gas migration processes are inferred to be active
flow to permeable sand layers in the Nankai Trough, and
long migration of thermogenic gas generated in deep mature
sediments through faults in the Mackenzie Delta. |
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11000
|
Hydrogen production with steam reforming of dimethyl
ether^Poster
|
EXPO World Conference on Wind Energy, Renewable Energy,
Fuel Cell & Exhibition
2005/6/7 |
Takeishi Kaoru, Akane Arase(Shizuoka University)
|
Research Project Team on Emerging Gas Technologies
|
| [Abstract] Steam reforming of methanol and gasoline are actively
researched as hydrogen supply methods for fuel cells of
vehicles, and so on. However, these materials have problems
such as the infrastructure, toxicity, difficulty of reforming,
and so forth. Dimethyl ether (DME) is expected as one
of clean fuels, and DME is one of substitutes of diesel
fuels and LPG. Infrastructures of LPG will be able to
use for DME. Therefore, we have been studying on DME steam
reforming for hydrogen production. Copper alumina catalysts
prepared by a sol-gel method produced large quantities
of H2 and CO2 with DME steam reforming at 300 ℃. Other
metal alumina catalysts prepared by the sol-gel method
produced H2 and CO2, but also produced large quantities
of CO. Our studies showed that copper is the best metal
for the production of H2 while producing less CO. Á-alumina
for DME hydrolysis into methanol, and copper for methanol
steam reforming to H2 and CO2 coexist on the surfaces
of catalysts prepared by the sol-gel method, and the catalysts
produce more H2 from DME than impregnation catalysts,
mixed catalysts, and so on. We have developed a great
potential for H2 supply from DME. |
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