초록 ▼

연차 목표
◦심지층에서의 CO₂ 거동특성 평가기술 개발
◦CO₂ 지화학적 모니터링 파라미터 산정 및 모니터링 절차 작성
◦지질구조 및 응력장 분석 기반 CO₂ 저장특성 및 안정성 검토
◦탄성파 모니터링 기법의 성능 평가 및 분석기법 기초 확립
◦잠재 CO₂저장부지의 물성, 지질조건, 유동특성 분석을 통해 부지특성을 고려한 최적 모니터링 시스템 구축 방안 제시
개발내용 및 결과
◦시뮬레이션을 이용한 다중 지층에서 CO<

연차 목표
◦심지층에서의 CO₂ 거동특성 평가기술 개발
◦CO₂ 지화학적 모니터링 파라미터 산정 및 모니터링 절차 작성
◦지질구조 및 응력장 분석 기반 CO₂ 저장특성 및 안정성 검토
◦탄성파 모니터링 기법의 성능 평가 및 분석기법 기초 확립
◦잠재 CO₂저장부지의 물성, 지질조건, 유동특성 분석을 통해 부지특성을 고려한 최적 모니터링 시스템 구축 방안 제시
개발내용 및 결과
◦시뮬레이션을 이용한 다중 지층에서 CO₂와 염수의 거동 특성 평가
◦용존이온, 동위원소, noble gas 등을 적용하여 CO₂ 거동 해석
◦모니터링 시나리오 별 적정 지화학 파라미터 선정
◦지화학 모니터링 항목별 목표, 시료채취/분석방법, 모니터링 주기, 공간적 범위 등에 대한 내용을 포함하는 매뉴얼 도출
◦공극률 및 공극구조에 따른 CO₂ 저장성/잔류성 및 CO₂ 모니터링을 위한 암석물리 연구
◦포항분지 단층암 대상 실내 물성 측정 및 CO₂주입후 단층 재활성 가능성 분석
◦실내실험 결과를 통한 CO₂ 유동과의 상관 관계 특성 분석(코어 실험/분석)
◦CO₂ 거동/누출 시나리오에 기반한 탄성파 모니터링 기술의 평가 기법 도출(모델링)
기대효과
◦CO₂ 모니터링 기술 자립도 향상을 통한 국내 산업 기반 및 경쟁력 확보
◦CO₂ 모니터링 핵심기술개발을 통해 CO₂ 배출권 확보를 위한 산업
-경제적 독립성 확보
◦저장 안정성 평가 기반기술 개발을 통한 CO₂ 지중저장의 대중적 인정(public acceptance) 확인
적용분야
◦파일럿 규모 CO₂저장 실증
◦CO₂포집 연계 상용화 규모 통합 CCS 플랜트

Abstract ▼

In this study, Pressure distribution and CO₂ plume migration are two major interests in CO₂ geologic storage as they determine the injectivity and storage capacity. In this study, we adopted a three-layer model comprising a storage formation and the over- and underlying seals a

In this study, Pressure distribution and CO₂ plume migration are two major interests in CO₂ geologic storage as they determine the injectivity and storage capacity. In this study, we adopted a three-layer model comprising a storage formation and the over- and underlying seals and determined three distinct flow regions based on the vertical flux exchange of CO₂ and native brine. Regions 1 and 2 showed CO₂ flowing from the storage formation to adjacent seals with counter-flowing brine.The characteristics of these fluxes inRegion 1were governed by permeability change due to salt precipitation whereas buoyancy force controlled the flux pattern in Region 2. Region 3 showed brine flowing from storage formation toward the overand underlying seals, which enabled the displaced brine to escape from the storage formation and make room for CO₂ to store as well as reduce the pressure build-up. In the multi-layered model, the counter-flowing brine in flow Region 1 resulted in localized salt precipitation at the upper and lower boundary of storage formation. We assessed the bottom-hole pressure and CO₂ mass in caprock with respect to reservoir size. While the formation thickness influenced the bottom-hole pressure in the early stage of injection, the horizontal extension of the reservoir was more influential to pressure build-up during the injection period, and to the stabilized pressure during the post-injection period. The CO₂ mass in caprock gently increased during the injection period as well as during the post-injection period and reached about 4–5% of injected CO₂. The percentage of escaped brine from the storage formation ranged from 80–100% of the CO₂ mass stored in the storage formation depending on the reservoir scale.
Geochemical parameters such as pH and DIC which were directly reflect the changes of geochemistry after injection of the large amount of CO₂ could be used for indicator of geochemical monitoring. However, indirect parameters such as the changes of dissolved ion and isotopic composition could be useful when direct parameters were discriminate the changes of geochemistry of the storage reservoir. Site characterization information such as mineral composition of target formation and cap rocks, hydrological condition were needed for using indirect parameters for monitoring. Soil CO₂ monitoring on the storage site and its periphery is important because soil layer could be a terminal leakage pathway and effect the human and near-surface environment. Soil monitoring classified into surface soil CO₂ flux monitoring and vadose zone gas monitoring. KIGAM’s CO₂ research team have established the method of soil CO₂ monitoring could be applied in CO₂ storage project. Standard method for soil CO₂ monitoring should be established by testing the applicability of soil CO₂ monitoring system.
The injection of carbon dioxide into a porous reservoir leads to the increase of its pore-pressure. In many cases, discontinuous planes such as faults and joints exist in the vicinity of a candidate site for geological CO₂ storage. The increase of pro-pressure in the reservoir above a threshold value may cause a reactivation of the preexisting faults, which may result in a leakage of injected CO₂. Therefore, the risk of reactivation of preexisting faults should be assessed during the stage of site characterization. For the assessment one need to collect data such as 3D fault geometry, in-situ stress orientation and magnitude, and frictional strength of the fault. In this study, we have carried out a set of double direct shear tests with the fault gauges collected from the outcrops of the faults existing in the candidate site for geological CO₂ storage and located in SE, Korea. For all the fault gauge samples, we have observed a common frictional strength behavior that shows strength weakening or elasto-plastic behavior in relatively lower normal stresses (5 and 10MPa), however, strength hardening in relatively higher normal stresses (20MPa). The friction coefficients are measured in the range of 0.2 to 0.5, and an extremely lower friction coefficient, about 0.2, has been observed in the samples (Ocheon 2-1, 2-2 and Bokyungsa 3-1). It appears that such a low friction coefficient is associated with relatively smaller grain size, lower content of crystalline minerals, and relatively higher total clays and amorphous content.
To understand potential geological processes in sedimentary strata caused by the buildup of abnormal fluid pressure, we conducted detailed observation of clastic sediment injection structures found in an outcrop of the Pohang basin. Mudrocks occur dominantly in the outcrop, and thin sand layers are only locally intercalated with them. The sediment injection structures found in the outcrop are characterized by the upward movement and infilling of unconsolidated mud into tensile fractures in the mudrocks. Both the mud injection structures observed in the outcrop and some sand dykes found in other places of the Pohang basin appear to indicate that hydrofracturing caused by abnormal fluid pressure buildup may be accompanied with sediment injections and fluid leakage.
We have conducted experimental simulations of dryout zone forms when CO₂ is injected into saline aquifers in order to understand whether injectivity can be impaired by salt precipitation in the form of the change in the structure and shape of pores. After the measurement of basic properties of Berea sandstone samples; porosity by the dry and wet densities and mercury porosity, and gas permeability, we saturated the samples with NaCl solution with different concentrations (3w%, 4w%, and 5w%). In order to simulate the dryout zone by CO₂ injection, the samples were located in an oven with 60° C for 24 hours, then used for the measurement of porosity and gas permeability. Mercury porosimetry gives the change in pore size distribution. When the saline-saturated samples were dried, the porosity was reduced by the salt precipitation, and so was the permeability. Based on the change in pore size distribution, the salt precipitation affects the pore throats by reducing their sizes, Our experimenal results agree with other various model studies that injectivity is impaired by salt precipitation near the injection well during CO₂ injection.
To evaluate the behaviour of the injected CO₂ under the ground, development of the integration technology of the laboratory experiment on the CO₂ injected core, the numerical reservoir simulation, and seismic modelling was investigated. First, we established and upgraded the previous experiment system by fixing the temperature inconsistency problem. In addition, CO₂ injection test was performed on Berea sandstone for verification of the core experiment system. Second, CO₂ injection field scale reservoir simulation and a format conversion of the reservoir simulation output data to the input for the seismic modeling were performed. Third, poro-elastic modeling algorithm which connects the petro-physical properties to geophysical or seismic attributes is developed and test.

목차 Contents

• 표지 ... 1
• 제 출 문 ... 3
• 연차보고서 요약서 ... 5
• 요약문 ... 6
• SUMMARY ... 12
• CONTENTS ... 15
• 목 차 ... 16
• 제 1 장 연구개발과제의 개요 ... 19
• 1.1. 연구개발의 목적 ... 19
• 1.2. 연구개발의 필요성 ... 21
• 1.2.1. 연구개발의 과학기술, 사회경제적 중요성 ... 21
• 1.3. 연구개발의 범위 ... 22
• 제 2 장 국내외 기술개발 현황 ... 24
• 2.1. 국내 기술개발 현황 ... 24
• 2.2. 국외 기술개발 현황 ... 26
• 제 3 장 연구개발 수행 내용 및 결과 ... 29
• 3.1. 심지층내 CO2 거동 특성 평가 ... 29
• 3.1.1. 서언 ... 29
• 3.1.2. 연구방법 ... 30
• 3.1.3. 연구결과 ... 33
• 3.1.4. 토의 ... 42
• 3.1.5. 결언 ... 43
• 3.2. 실시간, 원위치 지구화학 모니터링 시스템 ... 44
• 3.2.1. 서언 ... 44
• 3.2.2. 지구화학 모니터링 자연유사 사례 연구 ... 45
• 3.2.3. 지구화학 모니터링 프로토콜 ... 50
• 3.2.4. 결언 및 토의 ... 68
• 3.3. 한반도 동남부 일대에 분포하는 단층비지 전단특성 연구 ... 70
• 3.3.1. 서언 ... 70
• 3.3.2. 연구지역 ... 70
• 3.3.3. 연구방법 ... 71
• 3.3.4. 연구결과 ... 73
• 3.3.5. 결언 ... 78
• 3.4. CO2 주입에 따른 수압파쇄 자연유사 연구 ... 81
• 3.4.1. 연구배경 ... 81
• 3.4.2. 연구대상 ... 82
• 3.4.3. 연구결과 ... 82
• 3.4.4. 결언 ... 87
• 3.5. CO2 주입에 의한 저장층의 물리역학적 반응 및 모니터링 응용 ... 89
• 3.5.1. 서언 ... 89
• 3.5.2. 실험방법 ... 90
• 3.5.3. 실험결과 및 토의 ... 92
• 3.5.4. 결언 ... 95
• 3.6. 탄성파 모니터링 기법의 성능 평가 및 분석 기법 기초 확립 ... 96
• 3.6.1. 서언 ... 96
• 3.6.2. CO2 유동 특성 및 탄성파 특성 계측 심화 분석을 위한 실내 코어 물성 및 탄성파 특성 계측 실험 ... 98
• 3.6.3. 저류층 시뮬레이션의 유체 유동 모델링 기법을 이용한 탄성파 특성 변화 모델링 입력자료 생성 ... 102
• 3.6.4. 저류층 시뮬레이션-탄성파 특성 변화 모델링 연계를 위한 특성 변환 ... 106
• 제 4 장 목표달성도 및 관련분야에의 기여도 ... 110
• 4.1. 당해연도 연구성과 ... 110
• 4.1.1. 논문, 지재권, 기술이전 성과물 ... 110
• 4.1.2. 논문, 지재권, 기술이전 이외의 정량적 성과물 ... 114
• 4.1.3. 과제와 관련하여 창출된 기타 정성적 성과물 ... 115
• 4.2. 연구실적의 경제적 공공적 파급효과 ... 120
• 4.2.1. 정책적 측면 ... 120
• 4.2.2. 과학기술적 측면 ... 120
• 4.2.3. 경제 산업적 측면 ... 120
• 4.2.4. 국민생활과 사회 수준 향상에의 기여 측면 ... 121
• 제 5 장 연구개발결과의 활용계획 ... 122
• 5.1. 기대 효과 ... 122
• 5.2. 활용계획 ... 123
• 제 6 장 참고문헌 ... 124
• 부록 ... 131
• 끝페이지 ... 235