The energy sources and their utilizations seem to become diverse and make a continued shift from oil to natural gas. Technology developments to monetize natural gas such as CNG and NGH pursuing higher transportation efficiency and those of GTL, DME and GTW which transform from gas to other energy form have been progressed. Some of these options have achieved commercial applications. Floating LNG is also seriously studied to apply offshore gas development scheme. This paper describes features of these options and international trends of each technology.
Technologies concerning LNG carrier has been developed more than 50 years since 1950's. About 240 LNG carriers are in operation in 2007 and have an excellent long record of safety and stable LNG transportation at sea since 1959. In Japan, successful safety LNG transportation has been continued since the first import from Alaska in 1969 and 63 million tons LNG are imported in FY2006. Under huge demand of LNG, more than 350 LNG carriers including under construction shall shoulder important role of safety and economical LNG transportation around 2010. Recently, several innovative technologies about LNG carriers have been developed and designed to modern LNG carriers. As a viewpoint of LNG buyer, Charterer and Owner of LNG carrier, this review highlights these technologies as follows. LNG containment systems such as Moss, SPB and Membrane, new propulsion systems such as slow-speed diesel driven with natural gas reliquefaction, medium-speed dual fuel diesel generator with electric motor and high efficient steam turbine, large-scale LNG carrier up to 260,000m3 of LNG tank capacity, condition assessment program, natural gas fuel ship in EU and “LNG FPSO”.
The main way for natural gas transportation is pipeline all over the world. However there are some remote areas from LNG terminal where pipeline investment is too expensive to supply natural gas. For these areas, as an alternative means, LNG has been moved in Liquids by tank trucks since 1970 in Japan, so called LNG satellite system. This presentation introduces Japex's LNG satellite system including tank truck and tank container railway operation in Niigata and the small scale liquefaction plant in Hokkaido.
Teikoku Oil Co., Ltd. (TOC) completed Shizuoka-line (Koufu to Gotenba-City, 81km) at the end of 2006. Also, Shizuoka Gas Co., Ltd. (SZG), Tokyo Gas Co., Ltd. and TOC completed the Minamifuji-pipeline (Gotenba to Fuji-City, 31km) at that time. Those pipelines are in series and, with those completion, natural gas pipeline system between the Japan Sea and the Pacific Ocean was realized connecting with the Minami-nagaoka natural gas field (also with the Sekihara underground gas storage) in Niigata prefecture and the Sodeshi LNG receiving terminal of SZG in Shizuoka prefecture. Since domestic gas and imported gas (LNG) can be fed into the pipeline system, it is strongly expected that gas supply in the eastern area of Honshu Island becomes more flexible and reliable.
The BTC crude oil pipeline runs 1,768 km from the Sangachal Terminal near Baku in Azerbaijan, via Tbilisi in Georgia, through to the Ceyhan Marine Terminal on Turkish Mediterranean coast. The pipeline has started its operation on June 2006 and exported around 220 million barrels as of the end of September 2007. This presentation introduces the outline of drag reducing agent (DRA) which is currently evaluated for the purpose of increasing the pipeline capacity, and the sophisticated leak detection system (LDS) installed in the system.
Traditionally, natural gas is transported by pipelines or by ships as liquefied natural gas (LNG). Because of large costs of liquefaction plants and carriers for natural gas, LNG transportation system has been applied only to very large gas fields. For meeting the increasing demand and stable supply of natural gas, small and medium size gas fields need to be utilized. To enable the utilization of small and medium size gas fields, it is necessary to develop another transportation system for natural gas, with lower initial costs. Gas hydrate is a crystalline solid which consists of gas molecules each surrounded by a cage of water molecules. Use of gas-hydrates for transportation of natural gas was first proposed by Gudmundsson et al. (Norway) in 1996. The temperature of natural gas hydrate (NGH) through transportation remains higher than that of liquefied natural gas (LNG), and accordingly, transportation of NGH is expectably more flexible in terms of its facilities and equipments. NGH can be a medium for natural gas transportation for comparatively small gas fields to which LNG transportation system is not economically applicable. The development of the NGH transportation system started in year 2001. This paper outlines the system and results of current study.
LNG has been the major oversea transportation means since the era of 1970. The development costs of LNG plant, export and import terminals and LNG carriers have been very expensive, then only huge gas fields more than several Tcf reserves have been developed which enables initial cost recovery. Technical innovation, clean energy demand and the current oil price ascent are leading the stranded gas fields development by use of new gas transportation technology. Among them CNG (compressed natural gas) is one of the means which has low energy loss in the CNG processing compared to chemical transformation such as GTL (gas to liquid) and is capable to supply gas directly to the gas pipeline grid by easily re-gasification on board CNG carrier. This paper describes technical and economical characteristics of CNG and its application among many gas transportation systems.
GTL (Gas-to-Liquids) is the key strategic technology to secure natural gas resources as alternative source of liquid fuel and its products are expected to have high qualities as clean fuel and lubricant base oil. Nippon GTL Technology Research Association and JOGMEC launched a joint demonstration project last year to verify the process performance of unique JAPAN-GTL technology on the scale of 500B/D, which is the final step toward commercial use of the technology. In the project, scaling-up methods, from demonstration to commercial scale (more than 15,000B/D/train), will be also studied with the goal of developing both technically and economically competitive GTL technology.
To mitigate the global climate change due to excess carbon dioxide emission, geologic sequestration by carbon dioxide injection in the subsurface has been proposed. To monitor and verify the long-term safe storage in the subsurface, 4D or time-lapse 3D seismic technology is the most effective to spatially and efficiently detect the change of fluid saturation and pore pressure in the target aquifer and others. In RITE/METI Nagaoka carbon dioxide injection test field, 4D seismic survey was conducted to monitor injected carbon dioxide as a collaborative research of Japex and RITE/METI. It was the first 4D seismic survey for onshore aquifer injection monitoring in the world. Target reservoir in saline aquifer is at approximately 1100m deep. Carbon dioxide saturation was observed with approximately 6m thick by logging survey. To estimate the saturation zone by 3D seismic surveys, I had to overcome the problems of data acquisition and processing, i.e., 1) irregular 3D geometry in the land 3D seismic surveys, and 2) to enhance data resolution to meet the thinner target reservoir. In order to detect and highlight 4D anomaly zones, for relatively high noise content data, it is inadequate to simply subtract baseline and monitor seismic data as there are no ways to discriminate the noises from geological changes by this volume alone. It turns out that 4D anomaly detectability is improved if supervised pattern recognition technology is implemented in the multi-attributes approach. Estimated anomaly pattern is consistent with the observation of time-lapse wireline data and total amount of injected carbon dioxide incorporated with probability of distribution. It has improved the results of visual inspection of simple math difference of 3D seismic volume. 3D data were evaluated using well synthetics data and impedance inversion data to estimate several physical parameters such as porosity and permeability combined with the wireline data and geological constraints. Estimated high permeability zone by baseline data prior to the repeat survey showed a correlation with the detected 4D anomalies. The first onshore 4D seismic monitoring of the injected carbon dioxide in aquifer was successfully conducted, though there were difficulties caused by the irregular 3D geometry and thinner target reservoir. It provides the prototype approach to the similar onshore carbon dioxide monitoring.