• Proceedings of the Korean Society for Rock Mechanics Conference
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• 2002.10a
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• pp.1-15
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• 2002

동복터널의 현장지질은 편마암과 석탄층(Coal Beds)이 협재된 암질이 매우 불량한 편암으로 구성되어 있으며, 설계 시에는 석탄층의 발달이 확인되지 않아 그 영향을 충분히 고려되지 않았다. 석탄층(두께 2~8m)은 편암의 Rock Cleavage와 같은 방향과 45~55도의 경사를 가지며 pinch out and swelling 형태로 발달이 불규칙하다. 하행선굴착 중 약 290m구간에 걸쳐 석탄층이 나타났으며, 90m 구간은 천단 및 측벽부에서 집중 발달되어 쳐대일변위가 20mm이상인 지점이 발생하는 등 상반굴착 시 111.2mm의 수평방향 내공변위가, 하반굴착 시에는 최대 127.8mm의 내공변위가 발생하였고 하반관통이후 수렴되었다. 내공변위 과다발생에 대한 대책으로 지보타입을 하향 조정하였고 측벽부는 하향 록볼트를 포함한 추가록볼트 보강을 실시하였다. 한편 터널 바닥부의 석탄층은 도로포장 후 침하문제가 예상되어 인버트를 기존 강지보공과 H-beam으로 연결.폐합한 후 콘크리트로 치환(140m구간)하여 추가변위를 최소화하였으며 무근콘크리트로 설계된 라이닝은 철근콘크리트 라이닝으로 변경 시공하였다.

• Economic and Environmental Geology
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• v.47 no.4
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• pp.455-466
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• 2014

We investigated reservoir properties of coalbed methane and typical development of drilling, completion, and stimulation methods. We optimized selection technique for development methods by consifering characteristics of coalbed methane resercoir in the San Juan, Black Warrior and Powder River basins of United States. Finally, well-optimized development methods for coalbed methane in the Barito Basin, Indonesia are suggested. This study may be useful to select economical and efficient drilling, completion, and stimulation methods in coalbed methane development especially in Indonesia.

• Journal of the Korean Institute of Gas
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• v.18 no.2
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• pp.1-9
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• 2014

To develop a coalbed methane(CBM) reservoir, it is important to apply production methods such as drilling, completion, and stimulation which coincide with coal properties. However, the reliability of the selected resulted in most of CBM field is not enough to accept because the selection of production method has been done by empirical decision. As the result, the empirical decision show inaccurate results and need to prove using simulation whether it was true exactly. In this study, the intelligent system has been developed to assist the selection of CBM production method using artificial neural network(ANN). Before the development of the system, technical screening guideline was analyzed by literature survey and the system to select drilling and completion method, and hydraulic fracture fluid was developed by utilizing the guideline. The result as a validation of the developed system showed a high accuracy. In conclusion, it has been confirmed that the developed system can be utilized as a effective tool to select production method in CBM reservoir.

• Economic and Environmental Geology
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• v.55 no.3
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• pp.261-271
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• 2022

Six gas samples were collected from coal and coaly shale from core AA-1, which was acquired from the Asem-Asem Basin, southeast Kalimantan, Indonesia. These coalbed gas samples were analyzed for the molecular composition, carbon isotope (δ¹³C_CH4, δ¹³C_C2, and δ¹³C_CO2), hydrogen isotope (δD_CH4), hydrocarbon index (C_HC), and carbon dioxide-methane index (CDMI) to document their origin and methanogenic pathways. Core AA-1 successively consists of lower clastic sedimentary rocks (Sedimentary Unit-1, SU-1) containing coal and coaly shale, and upper limestone (Sedimentary Unit-2, SU-2), unconformably underlain by serpentinized basement interpreted as part of the Cretaceous Meratus subduction complex (MSC). The coal and coaly shale (SU-1) were deposited in a marshes nearby a small-scale river. Compositions of coalbed gases show that methane ranges from 87.35 to 95.29% and ethane ranges from 3.65 to 9.97%. Carbon isotope of coalbed methane (δ¹³C_CH4) ranges from -60.3 to -58.8‰, while hydrogen isotope (δD_CH4) ranges from -252.9 to -252.1‰. Carbon isotope of coalbed ethane (δ¹³C_C2) ranges from -32.8 to -31.2‰, carbon isotope of coalbed carbon dioxide (δ¹³C_CO2) ranges from -8.6 to -6.2‰. The coalbed CO₂ is interpreted to be an abiogenic origin based on a combination of δ¹³C_CO2 and CDMI and could have been transported from underlying CO₂ bearing MSC through faults. The methanogenic pathways of coalbed gases are interpreted to have originated from primary methyl-type fermentation and mixed with CO₂ reduction, affecting thermogenic non-marine coal-type gases based on analyses of isotopic ratios and various indexes.

• Proceedings of the KSEEG Conference
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• 2003.04a
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• pp.213-216
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• 2003

1990년대에 들어와서 미국을 비롯한 석탄자원 부국들은 석탄층메탄가스자원을 에너지로 이용하는데 성공하였으며 현재 그 생산과 이용규모를 빠르게 확대해 나가고 있다. 우리나라의 경우 약 15억 톤의 무연탄자원이 확인되지만 수요처 상실로 1980년대 후반부터 석탄합리화 과정을 통해 석탄생산량은 2700만 톤/년에서 400만 톤/년 이하로 급감 했으며 가행탄광 수도 350여 개에서 10개로 감소됐다. 이러한 추세로 보면 국내무연탄자원은 사실상 사장 화 될 처지에 놓이게 된 것이다. (중략)

• Journal of the Korean Institute of Gas
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• v.27 no.2
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• pp.39-48
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• 2023

This study presents the experimental results to measure the adsorption amount of methane gas by coal according to the conditions of a coalbed methane (CBM) reservoir. Adsorbed gas to coal seam particles was measured under reservoir conditions (normal pressure ~ 1,200 psi pressure range, temperature range15 ~ 45℃) using coal samples obtained from random mines in Kalimantan Island, North Indonesia. The obtained amount of absolute adsorbed gas was applied to triangular with linear interpolation to calculate the maximum amount of adsorbed gas according to temperature and pressure change, at which no experiment was performed. As a result, it was revealed that the amount of adsorbed gas to coal particles increased as the pressure increased and temperature decreased, but the increase of the amount of adsorbed gas decreased at more than an appropriate depth(1,000 ft). In the cleat permeability and cleat porosity for each depth of the coal bed considering the effective stress, the cleat permeability was 28.86 ~ 46.81 md, and the cleat porosity was 0.83 ~ 0.98%. This means that the gas productivity varies significantly with the depth because the reduction of the permeability according to the depth in the coal seam is significant. Therefore, a coalbed depth should be considered essential when designing the spacing of production wells in a coalbed methane reservoir in further study.

• Economic and Environmental Geology
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• v.46 no.4
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• pp.351-358
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• 2013

Methane burns more clearly than any other fossil fuels. Coalbed methane(CBM) is natural gas contained in coal beds. This gas is usually producted from coal that is either too deep or too poor-quality to be mined commercially. While global coalbed methane resource estimates are rough, they indicate between 84 and 377tcm, which compares with proven natural gas reserves of 180tcm. Coalbed methane resources are currently only produced on a major scale in the United States, Canada, Australia and China. In this study, we analysed total 109 published papers for the CBM during the 1990~2012 periods by the programs of 'web of science'. The results of analysis, the CBM study led by the United States, the follow India and Australia. In subject area(web of sciences), Energy Fuels is 57, Engineering 58 and Geology 41 papers, respectively.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.115.1-115.1
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• 2010

석탄 가스화기술은 기존의 연소 방식에서 발생하는 공해 물질은 줄이면서 발생되어지는 합성가스를 이용하여 직접 사용하거나, IGCC나 CTL 공정등에서 원료로서 사용할 수 있다는 장점을 가지고 있어 석탄의 환경친화적인 이용을 위하여 오래전에 개발된 기술임에도 불구하고 최근 각광받고 있는 기술이다. 분류층 가스화기는 미분화된 석탄을 고온에서 가스화하는 방식으로 용량의 대형화가 가능하여 석탄가스화복합발전(IGCC)용으로 이용되고 있다. 석탄슬러리를 원료로 사용하는 습식 분류층 가스화기는 기술적으로 상당히 안정적이어서 가장 많이 보급되어진 가스화기 형태이다. 본 연구에서는 1.0T/D급 습식 분류상 가스화 장치의 가압 운전 특성 및 가스화 특성, 운전 조건을 파악하기 위하여 실험을 실시하였다. 실험에 사용된 반응기는 운전 압력 30bar로 설계되었으며, Fuel의 공급량은 50~70kg/hr로 공급하였으며, $O_2$/fuel Ratio를 0.7~1.1까지 변경하여 Fuel 주입량에 따른 내부온도 분포와 $O_2$/Fuel 비율에 따른 합성가스의 조성, 탄소 전환율, 냉가스효율 변화 특성을 알아보았다.

• Journal of the Korean Institute of Gas
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• v.23 no.3
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• pp.7-19
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• 2019

In this study, a model was developed for estimating deliverability considering the pressure dependent permeability and predicting production profile with Material Balance Equation(MBE) for Coalbed Methane(CBM) fields. The estimated deliverability was compared with the conventional deliverability based on CBM well testing data with coefficient of determination($R^2$). As a result, the former was 0.76 and the latter was 0.69. It was confirmed that the deliverability which consider the pressure dependent permeability is more adoptable when representing the productivity of CBM fields. Through this process, in order to calculate pressure dependent permeability when well testing data exist, a method to infer reservoir pressure within the radius of investigation was proposed. The production profile of 31 gas wells was predicted for 15 years, using the estimated deliverability and the MBE. After that, the results was compared with simulation results of the literature. The simulation results did not account the pressure dependent permeability and the developed model results considered that. As the applied field permeability rised 1.17 times, field production rate was increased approximately 15% than the literature results. According to other researches, the permeability of CBM fields can be rise 6 ~ 25 times. For these cases, the production profiles may have significant difference with conventional gas fields.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 2000.11a
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• pp.61-66
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• 2000

분류층 건식 석탄가스화 방식을 택하고 있는 아주대학교 내 BSU 가스화기는 반응 후 회분을 용융상태의 슬랙으로 처리하여 가스화기 하단으로 배출하고, 생성된 석탄가스는 가스화기 상부로 배출시켜 생성된 석탄가스로의 슬랙 유입을 최소화한 디자인이다. 이러한 분류층 가스화기는 고정층이나 유동층 방식의 가스화기에 비해 가스화기 출구에서의 온도가 130$0^{\circ}C$이상의 고온이 유지되므로, 미분탄을 사용하는 분류층 가스화방식에서는 미립 입자 일부가 비말동반되어서 미분탄내의 회재를 100% 용융 슬랙으로 처리하기는 불가능하고, 수 % 정도는 생성 석탄가스와 함께 가스화기 밖으로 배출된다.(중략)