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Many kinds of refining processes are used in the steelmaking industry. Molten metal contained in the bath of the processes is strongly agitated by gas injection. Meal droplets are carried up into the upper molten slag layer due to the gas-lift effect. Each metal droplet falls and finally returns to the lower metal layer although it is captured for a while at the metal-slag interface due to the interfacial effect. The behavior of molten metals near the interface is closely associated with the refining efficiency and metal loss. The residence time at the interface was investigated in this study. An analytical equation was derived for the residence time and a water model study was carried out to validate the equation. Water and silicone oil were used for the models of molten metal and slag, respectively. [ABSTRACT FROM AUTHOR]

A system for recovery of methane hydrate from the deep ocean floor has not been established. As one possible recovery system, a gas-lift system was investigated. Experiments were performed with a gas-lift system of 5 m height and 100 mm in diameter to determine the relationship between injected gas quantity and pumped water quantity. Vertical flow in the gas-lift pipe was calculated with a compressible one-dimensional two-fluid model to analyze flow in the recovery pipe of methane hydrate from the deep ocean floor. Basic equations were mass conservation equations and momentum conservation equations of each phase, the relation of volume fractions and the state equation of the gas phase. The calculation showed that optimal gas injection depths exist. Thus, the gas-lift system can be economically effective the recovery of methane hydrate from the deep ocean floor. Abstract A system for recovery of methane hydrate from the deep ocean floor has not been established. As one possible recovery system, a gas-lift system was investigated. Experiments were performed with a gas-lift system of 5 m height and 100 mm in diameter to determine the relationship between injected gas quantity and pumped water quantity. Vertical flow in the gas-lift pipe was calculated with a compressible one-dimensional two-fluid model to analyze flow in the recovery pipe of methane hydrate from the deep ocean floor. Basic equations were mass conservation equations and momentum conservation equations of each phase, the relation of volume fractions and the state equation of the gas phase. The calculation showed that optimal gas injection depths exist. Thus, the gas-lift system can be economically effective the recovery of methane hydrate from the deep ocean floor. [ABSTRACT FROM AUTHOR]

The society of petroleum engineers (SPE), established in 1957 and the world's largest academic society in the E&F industry, launched the distinguished lecturer (DL) program in 1961. Annually in recent 3 decades, around 30 DLs selected from all over the world provide special lectures to local section members. The author was selected as the first Japanese national DL in the program's 60-year history. In the year 2021-22, total 3 lecture tours were held as 2 virtual and 1 in-person programs due to the COVID-19 situation. The report summarizes the overview of SPE DL program and the author's experience of DL activities. [ABSTRACT FROM AUTHOR]

This paper presents a basic study for developing a new adhesion improvement method for railway vehicles, focusing on the tangential force characteristics between wheels and rails. In our previous studies, the following phenomena have been confirmed. First, the tangential force of the wheel/rail is increased by repeated rolling and sliding frictional force, and the tangential force is stabilized by the oxide film covering the contact surface. In addition, the tangential force under the condition where the humidity around the contact surface is low tends to be larger than that under high humidity condition. And finally, these phenomena indicate that the friction coefficient of wheel/rail can be increased by instantaneously reducing the humidity around the contact surface. Therefore, in this paper, we propose a method for improving the frictional force that reflects the above-mentioned results in our previous studies. In the proposed method, assuming that it is applied to re-adhesion control of railway vehicles, the frictional force of the wheel/rail contact is temporarily increased by lowering the humidity around the contact surface by injecting dry nitrogen gas less than 30% humidity. To verify the proposed method, using a pair of the small cylindrical specimen, tangential force was measured under the conditions with different humidity. In addition, in order to confirm the effect on the braking performance of actual railway vehicle, numerical analysis was carried out. As a result, the experimental result showed the frictional force is increased by up to approximately 40% under high humidity condition, and it was confirmed by the numerical analysis that the proposed method has an improvement effect on the reduction of braking distance during dry nitrogen gas injection even if the humidity condition around the contact surface is high.

Iwafune-Oki field is the unique offshore field currently under operation in Japan. It was discovered in 1983 and has been producing from several oil and gas reservoirs since 1990. Because the decline of oil production had been confirmed after plateau period, we started to examine IOR application to Zone 2100 m, which was main reservoir of this field. This study indicated that natural gas IOR, using the abundant gas contained in the other zone, was effective. The pilot injection test was started in December 2004. The transition from the test to regular operation was decided in 2006 with confirming the increment of production oil. We have continued the production operation with the success of this IOR, though our prediction suggested that we couldn't continue the production after 2009 without the IOR. By the end of 2015, the oil recovery ratio of Zone 2100 m was 4% higher than without the IOR. In addition, the profit limit of Iwafune-oki field was extended. [ABSTRACT FROM AUTHOR]

YuriHara oiL field，AKiTa was Discovered in 1981.THe peak rate was over 350 KL/Day, But the production is going down constantly because the plant processing capacity depends on gas sales. The preference of the customers Is sHIFTIng to LlquefieD naturaL gas, and the naturaL gas sales tend to Be Down. For solving the productivity Restriction，we starteD to inject tHe excessive gas into tHe reservoir, expecting tHe increase of oiL proDuction. THe target reservoir consists oF BasaLt witH HigH Heterogeneity. We are trying to Forecast tHe oiL production aFter tHe gas injection witH geo-statisticaL models, But It's still Difficult to estimate the facies DistrlBution and permeaBiLity DistrlBution on the compLicated volcanic reservoir. THereFore, we Focus on tHe materiaL BaLance oF gas injection in order to investigate tHe reLationsHip oF weLL connectivity. WatchinG the production history of each well, we successfully specified the Injector-producer connectivity In some extent. After that, we are planning to do interference test in order to optimize the injection rate of each injector. [ABSTRACT FROM AUTHOR]