가스하이드레이트 개발과정에서의 단층 재활성화 해석

김형목,김아람,Kim, Hyung-Mok,Kim, A-Ram 한국암반공학회 2016 터널과지하공간 Vol.26 No.2

본 논문에서는 해저 하이드레이트 퇴적층에서의 메탄가스 생산 과정에서 발생 가능한 생산정 주변 단층의 재활성화 가능성을 수치해석을 통해 평가하고 재활성화에 따른 미소지진 규모를 예측한 결과를 소개하였다. 가스 생산에 의한 하이드레이트 퇴적층의 유효응력 변화 및 역학적 변형은 TOUGH+Hydrate 코드와 FLAC3D 코드를 순차적으로 연계해석함으로써 시뮬레이션하였다. 단층면 재활성화 기준은 모어쿨롱(Mohr-Coulomb)법칙이 유효한 것으로 가정하였다. 30일간의 시험생산 해석 결과, 감압에 의한 공극압력 감소 및 유효응력의 증가가 주변 단층의 활성화를 일으킬 가능성은 크지 않은 것으로 나타났다. 초기응력 조건에 따른 활성화 가능성을 활동마찰각으로 평가한 결과로부터 수평응력에 비해 수직응력이 상대적으로 큰 정단층 응력조건(normal fault stress regime)에서 단층 재활성화 가능성이 상대적으로 큰 것으로 파악되었다. 또한, 정단층 응력조건에서 단층 재활성화에 기인한 유도지진 발생규모를 모멘트 크기(moment magnitude)로 추정할 경우, 모두 음(-)의 값을 보여 인간이 감지하지 어려운 수준의 미소지진에 해당하는 결과를 보였다. 다만, 본 해석은 하이드레이트 생산과정에서의 단층재활성화 가능성 평가를 목적으로 한 해석기법 구축 및 그 적용성을 소개할 목적으로 상당히 단순화된 지질구조 모델을 가정한 결과이므로, 향후 하이드레이트 시험 생산 및 상업 생산 지역에서의 상세 지질구조, 입력 물성 및 생산 설계조건을 반영한 해석에서는 상이한 결과를 보일 수 있을 것이다. In this paper, we perform a numerical analysis to evaluate the potential of fault reactivation during gas production from hydrate bearing sediments and the moment magnitude of induced seismicity. For the numerical analysis, sequential coupling of TOUGH+Hydrate and FLAC3D was used and the change in effective stress and consequent geomechanical deformation including fault reactivation was simulated by assuming that Mohr-Coulomb shear resistance criterion is valid. From the test production simulation of 30 days, we showed that pore pressure reduction as well as effective stress change hardly induces the fault reactivation in the vicinity of a production well. We also investigated the influence of stress state conditions to a fault reactivation, and showed that normal fault stress regime, where vertical stress is relatively greater than horizontal, may have the largest potential for the reactivation. We tested one simulation that earthquake can be induced during gas production and calculated the moment magnitude of the seismicity. Our calculation presented that all the magnitudes from the calculation were negative values, which indicates that induced earthquakes can be grouped into micro-seismic and as small as hardly perceived by human beings. However, it should be noted that the current simulation was carried out using the highly simplified geometric model and assumptions such that the further simulations for a scheduled test production and commercial scale production considering complex geometric conditions may produce different results.

복공식 지하 압축공기에너지 저장공동 기밀시스템 설계변수의 민감도 해석

김형목(Hyung-Mok Kim),Jonny Rutqvist,류동우(Dong-Woo Ryu),선우춘(Choon Sunwoo),송원경(Won-Kyong Song) 한국암반공학회 2011 터널과지하공간 Vol.21 No.4

본 연구에서는 압축공기에너지 지하저장을 위한 복공식 암반공동의 기밀성능을 평가할 목적으로 다상유체 열유동 해석을 수행하였다. 기밀성능은 저장공동으로부터 누출되는 공기질량으로 평가하였으며, 저장공동 내부에 콘크리트 라이닝 기밀시스템을 설치하고 저장공동은 비교적 천심도인 지하 100m 심도에 위치하는 것으로 가정하였다. 저장공동 내 질량수지분석 결과, 콘크리트 라이닝 및 주변 암반의 투과계수가 누기량 및 저장공동의 장기적 기밀성능에 미치는 영향이 큰 것으로 파악되었으며 콘크리트 라이닝의 투과계수가 1.0 × 10?¹? ㎡ 이하 일 경우, 저장공동 운영압력이 5 ㎫에서 8 ㎫ 사이일 때 누기량은 1%이하 인 것으로 계산되었다. 또한, 콘크리트 라이닝의 초기포화도에 따른 공기누출량 계산결과, 라이닝 수분포화도를 증가시킬수록 누기량은 감소하고 저장공동 기밀성능이 향상됨을 확인하였다. We performed a numerical modeling study of thermodynamic and multiphase fluid flow processes associated with underground compressed air energy storage (CAES) in a lined rock cavern (LRC). We investigated air tightness performance by calculating air leakage rate of the underground storage cavern with concrete linings at a comparatively shallow depth of 100 m. Our air-mass balance analysis showed that the key parameter to assure the long-term air tightness of such a system was the permeability of both concrete linings and surrounding rock mass. It was noted that concrete linings with a permeability of less than 1.0 × 10?¹? ㎡ would result in an acceptable air leakage rate of less than 1% with the operational pressure range between 5 and 8 ㎫. We also found that air leakage could be effectively prevented and the air tightness performance of underground lined rock cavern is enhanced if the concrete lining is kept at a higher moisture content.

CO₂ 지하저장과 연계한 원유회수증진 기술

김형목(Hyung-Mok Kim),배위섭(Wi-Sup Bae) 한국암반공학회 2013 터널과지하공간 Vol.23 No.1

본 고에서는 CO₂ 지중저장과 연계한 원유회수증진 기술을 소개하였다. 원유회수증진을 목적으로 CO₂를 저류층 내에 주입하는 CO₂ EOR 기술은 장기적인 관점에서 CO₂를 지하 심부 암반에 저장하는 CCS 기술로 전환할 수 있다. CCS와 연계한 CO₂ EOR 기술은 EOR에 필요한 대규모 CO₂ 공급원을 확보할 수 있는 장점이 있으며 원유 회수율 증진에 따른 편익 발생으로 CCS를 위한 일련의 프로세스 중, 특히 포집 분야에 경제성을 부가할 수 있는 장점이 있다. 이러한 CCS와 연계한 CO₂ EOR 기술의 특징 및 시장 전망을 살펴보고 국외의 대표사례로 Weyburn CO₂ EOR 프로젝트를 소개하였다. 또한, 안정적이고 경제적인 CO₂ EOR 실시에 필요한 제반 기술 요소를 분석하고 CO₂ 주입중 및 주입후 장기운영과정에서의 미소진동 계측, CO₂의 최소혼화압력 및 최대주입압력의 사전설계 등의 암반공학적 쟁점들을 소개하였다. Enhanced oil recovery (EOR) technology coupled with underground carbon dioxide sequestration is introduced. CO₂ can be injected into an oil reservoir in order to enhance oil production rate and CO₂ EOR can be turned into CCS in a long term sense. Coupling CO₂ EOR with CCS may secure a large scale and consistent CO₂ source for EOR, and the CO₂ EOR can bring an additional economic benefit for CCS, since the benefit from enhanced oil production by CO₂ EOR will compensate costs for CCS implementation. In this paper, we introduced the characteristics of CO₂ EOR technology and its market prospect, and reviewed the Weyburn CO₂ EOR project which is the first large-scale CO₂ EOR case utilizing an anthropogenic CO₂ source. We also introduced geotechnical elements for a successful and economical implementation of CO₂ EOR with CCS and they were a miscroseismic monitoring during and after injection of CO₂, and determination of minimum miscible pressure (MMP) and maximum injection pressure (MIP) of CO₂.

매쉬-심 용접 판재의 성형 한계

김형목(Hyung-Mok, Kim),허영무(Young-Moo, Heo),양대호(Dae-Ho, Yang),서대교(Dae-Gyo, Seo) 한국소성가공학회 1997 한국소성가공학회 학술대회 논문집 Vol.1997 No.5

점토질 퇴적암 내 굴착영향영역 투수특성의 시간경과 변화 파악을 위한 수치해석기법에 대한 고찰

김형목(Hyung-Mok Kim),박의섭(Eui-Seob Park) 한국암반공학회 2020 터널과지하공간 Vol.30 No.6

본 고에서는 점토질 퇴적암 부지에 건설되는 처분갱도 주변 굴착영향영역에서의 투수특성을 평가하기 위한 수치해석기법을 검토하였다. 팽창성 점토를 함유한 퇴적암에 형성된 굴착영향영역 내 균열은 포화과정에서 점진적으로 간극을 상실하고 주변 모암의 투수계수에 수렴해 가는 자기 치유(self-healing) 혹은 자기 밀봉(self-sealing) 특성을 보이는 것으로 알려져 있다. 본고에 소개된 수치해석기법은 실내 및 현장실험을 통해 관측된 균열의 자기 치유 거동을 고려함으로써 처분장 건설 후 장기 운영과정에서 예상되는 굴착영향영역 투수계수의 시공간적 변화를 파악할 수 있는 특징이 있다. 지하연구시설 내 굴착 갱도 주변에서 현장투수시험을 통해 획득한 투수계수 측정치와 수치해석에 의한 결과를 비교 분석함으로서 활용타당성을 검증하였다. We reviewed numerical approaches to assess a hydraulic properties of excavation-disturbed zone (EDZ)created in argillaceous sedimentary rocks. It has been reported that fractures in the sedimentary rocks containing expansive clays are gradually closing due to swelling and their permeabilities are evolving to the level of in-tact rock, which is known as a self-healing or self-sealing process. The numerical approaches introduced here are capable of simulating spatio-temporal variation of EDZ permeability during long-term operation of a repository by including the self-healing characteristics of fractures, which wa observed in laboratory as well as in-situ experiments, The applicability of the numerical approaches was verified from the comparison to in-situ measurements of EDZ permeability at underground research laboratories.

업무 시나리오를 기반으로 한 소프트웨어 개선 프로세스의 모델링 및 활용에 관한 연구

김형목(Hyung-Mok Kim),류성열(Sung-Yul Rhew) 한국컴퓨터정보학회 2013 韓國컴퓨터情報學會論文誌 Vol.18 No.8

오늘날, 기업에서 업무의 80%이상이 정보시스템을 통해서 이루어짐에 따라 정보시스템은 복잡해지고 대형화되면서 이를 사용하는 사용자의 영역 또한 다양화 및 전문화 되고 있다. 그리고 최근 경영전략이 실시간 기업에 초점이 맞춰지면서 기업의 조직구조가 빈번하게 변화하고 있다. 이러한 상황에서 비즈니스의 연속성을 확보하기 위해서 유지보수자와 사용자의 업무 이해의 차이(Gap)를 해소하여 업무의 누락을 방지하는 것은 무엇보다 중요하다. 본 연구에서는 이러한 문제를 해결하기 위해서 사용자의 실제 업무 수행 규칙과 절차를 업무 시나리오로 작성하고 이를 최적화하고 정형화한 결과를 소프트웨어 유지보수 프로세스의 활동으로 전환하는 모델링 기법을 제안한다. 본 모델은 변경구현 결과에 대한 반복적인 피드백 체계를 통해서 점진적 상세화(fine-grained)를 유도하여 재사용성과 활용성을 높인다. 그리고 실무 적용을 통한 유효성 여부를 검증한다. As more than 80 percent of tasks within corporations are performed through information systems, they have become large in scale and complicated, which make the range of the system users diverse and specialized. and as recent corporate strategies focus on the real-time environment in businesses, the organizational structure within companies tend to show frequent changes. In order to ensure the business continuity in this environment, the most important aspect is to prevent incompleteness of business by narrowing the gap of understanding of business process between the system users and the maintenance managers. In order to address this problem, this study suggests a modeling method that utilizes business scenarios reflecting actual business rules and procedures which ultimately transforms the optimized and standardized form of business scenarios into the actual software maintenance activities. This modeling method improves reusability and usability through the repeated feedback mechanism for modified software by leading to gradual fine-grained process. The feasibility of this is to be proven by applying the modeling method to the real business environment.

대한제국기 인천지역 근대교육운동 주체와 성격

김형목(Kim, Hyung-Mok) 인천대학교 인천학연구원 2004 인천학연구 Vol.3 No.-

It was Younghwa Women s School that started modern education first in Incheon. For the first time, there was a little attention and no one made a noticeable result. However many opportunities to meet foreigners made people need modern education and government tried to make a good circumstances to modern education through running public schools. Enlightenment group like the DaeHanJaGang academic society(大韓自强會) led the Private school-establishing movements and Night school movements after the Treaty of 1905(乙巳條約). The athletic game with the neighbor regions was the chance to improve the Spirit of enhancing the military. The military gymnastic and military games were a kind of military excercise as like real one. The curriculums of those school were similar to public school s. They made the form of education manual according to their reality such as teachers, students and economy etc. Night school emphasized the teaching Japanese because Incheon is the port. The subject of founding and running schools were most protestants and the notable men in their rural and regions. The wide spectrum of the member showed the varieties of the goals and ideals. However Japanese education proved the limited reality recognition that they couldn t figure the Japanese cultural policy of colonizing Korean people. Incheon s modern education increased the sense of crisis of the educated. Moreover Younghwa Women s school was the center of early women education in

복공식 지하 압축공기에너지 저장공동의 열역학적 에너지수지 분석

김형목(Hyung-Mok Kim),박도현(Dohyun Park),류동우(Dong-Woo Ryu),최병희(Byung-Hee Choi),송원경(Won-Kyong Song) 한국암반공학회 2011 터널과지하공간 Vol.21 No.4

본 연구에서는 지하 압축공기에너지 저장공동 주변 지하수 및 압축공기의 유체유동과 열전달 거동 해석을 위한 다상다성분 열유동 해석 결과를 이용하여 지하 저장공동의 열역학적 에너지수지 분석을 통한 에너지 효율평가를 실시하였다. 복공재인 콘크리트 라이닝이 충분한 기밀성능을 발휘할 경우, 주입 · 압축과정에서 저장공동으로부터 손실되는 에너지의 대부분은 콘크리트 라이닝 및 주변 암반에의 열전도를 통해 발생함을 확인하였다. 지하 압축공기에너지 저장공동의 에너지 효율은 압축공기 주입온도에 민감한 결과를 보였으며, 주입온도가 주변 암반의 온도에 근사할 경우, 손실된 에너지의 대부분이 토출 · 팽창과정에서 저장공동으로 유입 · 회수되는 결과를 보였다. 한편, 콘크리트 라이닝의 열전도특성이 저장공동의 에너지효율에 미치는 영향은 크지 않았다. In this paper, we performed thermodynamic energy balance analysis of the underground lined rock cavern for compressed air energy storage (CAES) using the results of multi-phase heat flow analysis to simulate complex groundwater-compressed air flow around the cavern as well as heat transfer to concrete linings and surrounding rock mass. Our energy balance analysis demonstrated that the energy loss for a daily compression and decompression cycle predominantly depends on the energy loss by heat conduction to the concrete linings and surrounding rock mass for a sufficiently air-tight system with low permeability of the concrete linings. Overall energy efficiency of the underground lined rock caverns for CAES was sensitive to air injection temperature, and the energy loss by heat conduction can be minimized by keeping the air injection temperature closer to the ambient temperature of the surroundings. In such a case, almost all the heat loss during compression phase was gained back in a subsequent decompression phase. Meanwhile, the influence of heat conductivity of the concrete linings to energy efficiency was negligible.

온실가스(CO₂) 지중저장과 암반공학적 기술요소

김형목(Hyung-Mok KIM),박의섭(Eui-Seob PARK),신중호(Joong-Ho SYNN),박용찬(Yong-Chan PARK) 한국암반공학회 2008 터널과지하공간 Vol.18 No.3

본 고에서는 온실가스 감축방안으로 배출 CO₂를 지하심부에 격리저장시키는 지중저장기술의 국내외 기술동향을 살펴보고 지반 및 암반공학적 관련기술로서 CO₂ 주입에 따른 대상지층의 역학적 안정성 및 누출경로 평가를 위한 열-수리-역학적 연계해석기술 및 적용사례,기술개발요소를 소개하였다. In this study, state-of-the-art of CO₂ geological sequestration as a method of greenhouse gas reduction was reviewed. Thermal-Hydraulic-Mechanically(THM) coupled simulation technology and its application to a stability analysis of geological formation due to CO₂ injection as well as a leakage path analysis were investigated and introduced.

韓未 海西地方 夜學運動의 實態와 運營主體

金炯睦(Kim, Hyung-mok) 백산학회 2001 白山學報 Vol.- No.61

Night School Movement(夜學運動) in the region Haeseo(海西) developed in the form of founding private school. The central figures were government officials, teachers, rich persons, students in the higher education and so on. These were members of Seobuk academic society (西北學會) and Heaseo education general meeting(海西敎育總會), also mostly Christians. jeon, Bong-Hun(全鳳薰), county headman of Baechon(白川), and Lee, Yong-Pil(李容弼), county headman of Jaeryeong(載寧), as provincial officials, led not only Night School(夜學) but also campaign for enlightenment Kim, Ku(金九), educational affair inspector of Heaseo education general meeting at that time, took the lead not only in this region but in region Seobuk. So Yangsan School(楊山學校) and opening of summer institute reflected this. The scale of student number of Night School had a large variation from 10 to 180. The number of most Night School student was from 20 to 60. However Night Schools over 100 were the system similar to official education, made up of director, head teacher, teachers and employees. The number of persons, indebted to Night School, amounted to thousands at least This was never small than public schools. Learning period was continued mostly from six months to two years. However learning period of the Night Schools, supported by provincial officials and inhabitants, more prolonged relatively. Managing expense depended to more contribution than school fee. Unusually this expense was made up of duty educational fee, which inhabitants shared in according to level of life, The learning places for Night Schools made mostly use of private Schools and Town halls. Of course private houses also were used to Night Schools. Like this, the scale and equipment of Night Schools was not enough. Desire to learn, however, was not behind that of public schools. Sincerity of teachers, founders and supporters was main cause for the students desire to learn. The most of curriculums was made up of learning of Korean Letter, elementary Chinese Letter and arithmetic. The learning of Korean Letter would be the means of inspiring of national spirit, beyond merely crusade against illiteracy. Especially, physical exercises were importance to them with martial spirit. According to composition of learners and local conditions, moreover, curriculums were adopted and performed in various forms. Opening of Athletic meets made use of the moment of concentrating inhabitants on the one hand and the space of lecture meetings on the other hand. Activists of enlighten in the region Haeseo laid stress upon movement of founding private schools. Compared to the Night School Movement in other region, such as Gyunggido(京畿道), Pyungyangdo(平安道) and Seoul, these activities, however, prevented them from activating of the Movement. Along with reinforcing of military ruling, so-called Anak incident(安岳事件) brought about decisive weakening of overall national movement not to mention education movement After 3ㆍ1 Movement, the expansion of culture movement made chance of rise of Night School Movement Though, Night School Movement had problems such as tendency of opportunism in relation with national liberation movement. The critique of preparation argument of Shin, Chaeho(申采浩) had connection with the real state of affairs.