초록 ▼

국내 육상 퇴적분지에서 1만톤급 CO₂ 지중저장소 확보를 위해 육상 퇴적층 지표지질조사, 심부 지층 물리탐사/물리검층/시추를 수행하여 저장소 평가를 위한 양질의 자료를 확보하였다. 유망성 평가를 위해 지층의 암상 및 지화학적, 지구물리적, 암석역학적 분석 결과들을 도출하였다. 연구 지역인 태백산분지, 음성분지, 경상분지, 포항분지, 장기분지에 대한 CO₂ 지중저장 적합성 분석 결과, 국내 육상 퇴적분지에서 파일럿 규모의 이산화탄소 지중저장 후보지로 장기분지가 유망하며, 장기분지 심부의 장기역암

국내 육상 퇴적분지에서 1만톤급 CO₂ 지중저장소 확보를 위해 육상 퇴적층 지표지질조사, 심부 지층 물리탐사/물리검층/시추를 수행하여 저장소 평가를 위한 양질의 자료를 확보하였다. 유망성 평가를 위해 지층의 암상 및 지화학적, 지구물리적, 암석역학적 분석 결과들을 도출하였다. 연구 지역인 태백산분지, 음성분지, 경상분지, 포항분지, 장기분지에 대한 CO₂ 지중저장 적합성 분석 결과, 국내 육상 퇴적분지에서 파일럿 규모의 이산화탄소 지중저장 후보지로 장기분지가 유망하며, 장기분지 심부의 장기역암층이 유망 지층으로 가능하다. 1단계 연구에서 장기분지의 유망성을 확인하였고, 향후 추가 탐사와 시추를 보강하여 상세 지층 특성화 연구를 수행한 후에 최종 주입지 선정이 가능하게 되었다.

Abstract ▼

Ⅳ. Main results
○ Regional study on potential CO₂ storage in Taebaeksan Basin
- For assessing CO₂ storage potential in Taebaeksan Basin, regional stratigraphy and structures were reviewed and new-viewed in terms of integrated stratigraphy and structure.
- Thrust system

Ⅳ. Main results
○ Regional study on potential CO₂ storage in Taebaeksan Basin
- For assessing CO₂ storage potential in Taebaeksan Basin, regional stratigraphy and structures were reviewed and new-viewed in terms of integrated stratigraphy and structure.
- Thrust system observed in Yeongwol area was described and interpreted in detail. Thrust system contains structural closures with varying extent.
- The lowest part of Sambangsan Formation, mainly consisting of sandstones, is likely to be suitable for CO₂ storage because the sandstones are laterally thick enough to be reservoir.
- Major risk to store CO₂ in the lowest part of the Sambangsan Formation is its poor quality of sandstone reservoirs; porosity seems to be very low.
- It is necessary to investigate more details of the lower Sambangsan Formation in order to figure out where porous and permeable zones with structural closure are distributed.
○ Regional study on potential CO₂ storage in Eumseong Basin
- Based on outcrop studies including MT surveys, two potential sites are suggested for pilot-scale CO₂ storage.
- Potential sites have targets of coarse-grained sedimentary successions, which are very thick and are commonly interbedded with mudstone.
These association provides good reservoir-seal pairs.
- However, the extent of the basin is small and lateral change in facies are complicated. In addition, some sandstone samples show low porosity less than 5%. Volcanic activities caused decrease in porosity in the lower part of the basin
○ Regional study on potential CO₂ storage in Gyeongsang Basin
- For investigation of potential sites for CO₂ storage, geological and geophysical data were obtained from outcrop, well logs, seismic reflection, gravity, magnetic, and MT surveys in Uiseong, Euiryeong, and Jinju areas.
- Regional field works suggest that braided-channel sandstone bodies appear to be good reservoirs. The sandstone bodies are predominant in the upper part of the Nakdong Formation and the lower-middle part of Hasandong Formation. Porosity measured from sandstone samples taken in outcrops ranges from 4 to 8 % in Uiseong area, and 8 to 10% at Jinju area.
- 12 sedimentary facies are identified from description of three cores (YB-1, YB-2, and ER-1). They are organized into 3 facies associations. The facies associations 1, 2, and 3 represent channel, crevasse-splay and lake environments, respectively. Facies association 1 is interpreted as reservoir rock formed in braided-channel environments whereas facies association 2 and 3 as seal formation. Sandstones sampled from core have porosity of 0.8–8.7% (average 2.4%), 1.1–6.5% (average 2.6%), 1.6–2.7% in YB-1, YB-2, and ER-1 wells, respectively.
- Some sandstones with porosity more than 8% are marked at interval of 100-200m, 960m in YB-1 and ER-1, respectively. However, they seem to be impermeable and not to be common in the entire well.
- The effective porosity was estimated to be about 1.5% of the average value and be no more than about 1.2% in the Well YB-1, using the temperature/conductivity, natural gamma ray, and sonic logs.
- The result of the inversion of the MT survey shows that it is likely to be concordant successions and tilted toward the east expect the fracture zones along the NNW-SSE valley.
- Seismic data acquired in the Uiryeong and Uiseong area do hardly show the consistent and continuous successions because it is hard to distinguish the events of the reflection. One of the reasons why the mappable reflectors are not shown is that the contrast of the acoustic impedance has little difference due to similar high velocity (5.33 km/s). It is attributed to the high degree of the consolidation and compaction.
- Uiryeong area, where ER-1 was drilled, is likely to be one of the CO² geological storage compared with Uiseong area (YB-1 and YB-2) because the interval of 680-980m predominantly consists of sandstones with relatively high porosity (8%) zones.
○ Regional study on potential CO² storage in Janggi Basin
- The Miocene Janggi Basin in SE Korea consists of abundant volcanic deposits intercalated with fluvio-lacustrine sedimentary deposits.
- The basin fills are composed of the earlier strata bearing abundant dacitic volcanic materials, which are divided into Janggi Conglomerate and the Seongdongri Formation, and the later strata bearing abundant basaltic volcanic materials, which have been named Noeseongsan Basaltic rock.
- Janggi Conglomerate, depth of 744-1014m in JG-1 well, consists mainly of epiclastic rocks, which are intercalated with rare pyroclastic materials. Seongdongri Formation, depth of 120-744min JG-1, consists largely of light colored massive dacitic tuffs, which are intercalated with sandstone and mudstone. Noeseongsan Basaltic rocks, depth of 5-120m in JG-1, are characteristically dark and brown in color.
- Lithofacies analysis in Janggi Basin concluded that thick massive dacitic tuffs (Seongdongri Formation) are very suitable for a regional seal and the Janggi Conglomerate, which are mainly composed of conglomerate and coarse-grained sands, appears to have the characteristics suitable for a reservoir for CO₂ storage.
- Considering geological structure, characteristic, and distribution of lithology, there is high probability of extrusive region in the vicinity of the Mt. Noeseong. Basin fills tend to be thicker toward the West, resulting from the generally Northwest-dipping half-graben geometry and dip directions of Seongdongri Formation generally converge toward the Mt. Noesung. It suggests that basin fills are thicker than surroundings.
- It is necessary to confirm the existence of Janggi Conglomerate at deep level in the western part of Mt. Noesung.
- Magnetic and gravity survey was carried out at the 524 and 81 sites, respectively. The Janggi Basin has an average depth of 519.4 m, which is estimated by the power spectrum analysis of the converted magnetic anomaly data, and an average depth of 620.0 m, calculated by using the first derivative value of gravity anomaly through the power spectrum analysis.
- Three-dimensional gravity modeling for basin geometry shows that the depocenter exists along the western boundary fault and the basin is characteristics of thinning away from the boundary fault toward the east and southwest.
- The results from MT survey are the upper formation showing tens of ohm-m electrical resistivity and the lower formation showing hundreds of ohm-m electrical resistivity. Two dimensional inversion with a total of 62 stations and 5 survey lines is likely to exist large scale facture zone or fault along the linear structure A and B.
- The discontinuity following linear structure A is dipping toward the northwest whereas the discontinuity following the linear structure B is ambiguous where it is dipping toward.
- Distinct differences in the electrical resistivity of the upper and lower boundaries of the electrical unit layer are shown in the 800-1,000 m depth.
- The data obtained by seismic survey and borehole analysis suggest the possibility of a boundary between Janggi Conglomerate and Seongdongri Formation or Janggi Conglomerate and basement rocks.
- Faults caused by waveform distortion are observed in the seismic profile and some of them develop from basement to near surface along the vertical or inclined faults. In order to identify the direction and continuity of the faults, additional seismic surveys and VSP seismic survey are required.
- RMS velocities(2.8km/s, 3.4km/s, and 4km/s) of the three mappable reflectors in the well Janggi-1 correlate with about 280m, 680m, and 1160m, respectively. Top of the basement in the borehole correlates with the reflector at 580 msec(TWT) in the seismic profile.
○ Evaluation for CO² geological storage based on geochemical properties of the core-rock sample
- Laboratory experiments and calculation were performed to quantify the geochemical changes of sandstones for the reaction with supercritical CO² under the CO² sequestration condition in the Gyeongsang basin.
- The geochemical reactions, including surface roughness change, dissolution and secondary precipitation were quantified from laboratory experiments.
- The first-order dissolution constant (K1) of sandstones, calculated by using the loss of sandstone mass during the reaction time were ranged from 0.00008061 day-1 to 0.00008894 day-1 for sandstone. The results suggest that the dissolution of sandstones in the Gyeongsang basin might quickly occur after CO² injection. This study will be useful for estimating the geochemical reaction process with super-critical CO² under the CO² sequestration condition.
○ Subsurface geological model of Janggi Basin
- For prediction of basement depth in the area of interest, measured depths of basement were used as input data. However, it is not confident to map depth distribution due to the lack of well data. For these reasons, gravity and magnetic anomaly data were used as secondary data to generate depth maps of the top of basement and the base of Noeseongsan Basalt, respectively.
- Three depth structure maps were inserted into 3D geological grids: digital elevation map, the base of Noesungsan Basalt, and the top of basement in descending order. The geological model comprises two units.
- 3D geological model shows that the basin deeper that 800 m, a depth suitable for the injection supercritical CO₂, lies near the western boundary fault and it extends southward. The deep basinal area can be regarded as possible injection sites for CO₂ storage.
- Lithofacies are populated in the gridded model by using stochastic method with consideration of lateral continuity, vertical range and orientation for each lithofacies. The spatial distribution of lithofacies are simulated with no confidence due to the lack of well data, but the simulation implies that horizontal continuity and anisotropy of reservoir facies within Janggi Conglomerate are major uncertainty. It is necessary to investigate lateral and vertical variation in lithofacies and depositional elements to quantify their geometry and connectivity.

목차 Contents

• 표지 ... 1
• 제 출 문 ... 2
• 보고서 요약서 ... 3
• 요 약 문 ... 4
• 목 차 ... 10
• 표 목 차 ... 11
• 그 림 목 차 ... 14
• SUMMARY ... 29
• CONTENTS ... 35
• 제 1 장 연구개발 과제의 개요 ... 36
• 제1절 연구개발의 필요성 ... 36
• 제2절 연구개발의 목표 및 내용 ... 36
• 제 2 장 국내외 기술개발 현황 ... 37
• 제1절 국외수준 ... 37
• 제2절 국내수준 ... 40
• 제3절 관련 기술/제품의 국내 지식재산권(특허 등) 현황 ... 41
• 제 3 장 연구개발 수행 내용 및 결과 ... 45
• 제1절 태백산분지 CO2 지중저장 적합성 연구 ... 45
• 제2절 음성분지 CO2 지중저장 적합성 연구 ... 98
• 제3절 경상분지 CO2 지중저장 적합성 연구 ... 118
• 제4절 장기분지 CO2 지중저장 적합성 연구 ... 277
• 제5절 지화학적 특성에 근거한 지중저장 선정 평가 기술 개발 ... 375
• 제6절 장기분지 지질 모델링 ... 427
• 제 4 장 목표달성도 및 관련분야에의 기여도 ... 440
• 제 5 장 연구개발 대표성과 ... 441
• 1. 1만톤 규모 국내 육상 파일럿 CO2 지중저장을 위한 후보지 선정 ... 441
• 2. 지중저장소 평가를 위한 지구물리적, 지질학적, 지화학적 특성화 기반기술 확보 ... 443
• 제 6 장 연구개발결과의 파급효과 및 활용계획 ... 444
• 제 7 장 기타 ... 446
• 제 8 장 참고문헌 ... 453
• 끝페이지 ... 479