• Title/Summary/Keyword: Borehole System

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Development of Riverbank Filtration Water Supply and Return System for Sustainable Green House Heating and Cooling (지속가능 온실 냉난방을 위한 강변여과수 취수 및 회수시스템 개발)

  • Cho, Yong;Kim, Dae-Geun;Kim, Hyoung-Soo;Moon, Jong-Pil
    • The KSFM Journal of Fluid Machinery
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    • v.15 no.2
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    • pp.20-29
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    • 2012
  • The green house on the waterfront is air-conditioned by a water-source heat pump system with riverbank filtration water. In order to supply riverbank filtration water in alluvium aquifer, the riverbank filtration facility for water intake and recharge, two pumping wells and one recharge well, has been constructed. The research site in Jinju, Korea was chosen as a good site for riverbank filtration water supply by the surface geological survey, electrical resistivity soundings, and borehole surveys. In the results of two boreholes drilling at the site, it was revealed that the groundwater table is about 3 m under the ground, and that the sandy gravel aquifer layer in the thickness of 6.5 m and 3.5 m occurs at 5 m and 7 m in depth below the ground level respectively. To prevent the recharge water from affecting the pumped water which might be used as heat source or sink, the distance between pumping and recharge wells is designed at least 70 m with a quarter of recharged flow rate. It is predicted that the transfer term, the recharge water affects the pumping well, is over 6 months of heating season. Hydrogeological simulation and underground water temperature measurement have been carried out for the pumping and recharge well positions in order to confirm the capability of sustainable green house heating and cooling.

A Study of Numerical Analysis on Hydrogeological Influence by Groundwater Development around Underground Oil Storage Cavern (지하 석유비축기지 주변의 지하수 개발에 의한 수리지질학적 영향의 수치해석 연구)

  • 정현영;송무영;이경주
    • The Journal of Engineering Geology
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    • v.11 no.1
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    • pp.37-50
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    • 2001
  • Through the modeting study on the groundwater now system around the underground stockpile site of crude oil near Seoul, we carried out the research on the influence of the groundwater yield near the site, the effect of the water curtain construction in order to reduce the influence of water yield, and the realized case study by measuring the water level change after the construction of the water curtain. For the simu1ation of the water yield and the water curtain, the nwnerical analysis code, MODFLOW has been utilized. Groundwater levels of the observation wells which were established to observe the hydraulic head around underground oil storage cavern of the study area have been changed in the range of from EL.+30 to +60 meter, while the simulation study revealed that groundwater levels changed in the range of from EL.+20 to +5Om. The hydrogeological condition of the underground oil storage cavern becomes stable by injection water to maintain the groundwater level around the cavern. The result shows the proper input of the hydrogeological factors helps the management to be effective for the oil stockpile site.

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The Development of Straddle Packer Hydraulic Testing Equipment to Characterize Permeability in Deep Boreholes (장심도 시추공 정밀수리시험 장비 구축)

  • Kim, Kyung-Su;Park, Kyung-Woo;Ji, Sung-Hoon
    • The Journal of Engineering Geology
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    • v.20 no.2
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    • pp.213-220
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    • 2010
  • The permeability characterization on the natural barrier for deep geological disposal of radioactive waste is very critical to evaluate total safety and performance assessment of disposal site. However, the confidence level in using previous hydraulic testing equipments consist of simple components to estimate rock mass permeability is not high enough to reflect in situ condition. The purpose of this research is to establish an advanced hydraulic testing equipment, which is applicable to deep borehole (up to 1,000 m), through the improvement of technical problems of previous packer systems. Especially, the straddle packer hydraulic testing equipment was designed to adopt both the hydraulic downhole shut-in valve(H-DHSIV) to minimize the wellbore storage effect and the real time data acquisition system to measure the pressure changes of test interval including its upper and lower parts. The results from this research lead to not only improve current technical level in the field of hydraulic testing but also provide important information to radioactive waste disposal technology development and site characterization project.

Some case histories to detect underwater buried objects by electrical and magnetic methods (수중 매장물 조사에 응용되는 전기 및 자기 탐사사례)

  • JUNG Hyun Key;Park Yeong-Sue;Lim Mutaek;Rim Hyoungrae
    • 한국지구물리탐사학회:학술대회논문집
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    • 2004.08a
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    • pp.118-137
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    • 2004
  • Recently underwater geophysical problems for historical relics or UXO's are raised frequently. This study includes the applicabilities and limitations of the recent underwater metal detector and domestic case stories for underwater survey by electrical and magnetic method. Direct or indirect case stories are electrical and vertical magnetic gradiometry surveys beneath Han-river bottom for planning subway tunnel, electrical exploration on lake-bottom, electrical exploration on the tidal flats using high-power transmitter, and borehole three-component magnetic and electromagnetic surveys for detecting the undersea objects. A design of potable real-time, high-speed measurement system using multi-channel array sensors is also introduced here. Further study will be focussed on practical field applications of the fast water-bottom scanning system which is lately required by actual field.

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Study on the Geotechnical Characteristics of Granite in Korea and their Correlation with Rock Classification Method (국내 화강암의 지반공학적 특성 및 암반분류법과의 상관성에 관한 연구)

  • SunWoo, Choon;Ryu, Dong-Woo;Kim, Hyung-Mok;Kim, Ki-Seog
    • Tunnel and Underground Space
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    • v.21 no.3
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    • pp.205-215
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    • 2011
  • In this study, we analyzed physical properties of granites and their correlation with rock mass classification methods. The granite samples were obtained from field survey, in-situ borehole tests and laboratory tests for a design phase of various roads, railways and other civil engineering works in Korea. Among the measured physical properties, the results of unit weight, compressive strength, tensile strength, seismic velocity, cohesion, friction angle, elastic modulus and deformation modulus were introduced. We also correlated these properties with the compressive strength. The results of different rock classification method of RQD, RMR, and Q-system against the granites in Korea were compared with each other, and the correlation equations were proposed in a more simplified form. We also derived RMR values using the compressive strength as well as the RQD values of in-situ drilled cores, and estimated the deformation modulus of in-situ rock mass in terms of the RMR values.

Development of the 3-D Fracture Network Analysis and Visualization Software Modules (삼차원 불연속면 연결구조 해석 및 가시화 소프트웨어 모듈 개발)

  • Noh, Young-Hwan;Choi, Yosoon;Um, Jeong-Gi;Hwang, Sukyeon
    • Tunnel and Underground Space
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    • v.23 no.4
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    • pp.261-270
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    • 2013
  • As part of the development of the 3-D geologic modeling software, this study addresses on new development of software modules that can perform the analysis and visualization of the fracture network system in 3-D. The developed software modules, such as BOUNDARY, DISK3D, FNTWK3D, CSECT and BDM, are coded on Microsoft Visual Studio platform using the MFC and OpenGL library supported by C++ program language. Each module plays a role in construction of analysis domain, visualization of fracture geometry in 3-D, calculation of equivalent pipes, production of cross-section map and management of borehole data, respectively. The developed software modules for analysis and visualization of the 3-D fracture network system can be used to tackle the geomechanical problems related to strength, deformability and hydraulic behaviors of the fractured rock masses. All these benefits will further enhance the economic competitiveness of the domestic software industry.

Relationship between Dynamic Elastic Modulus and Lithology using Borehole Prospecting (시추공 물리탐사를 이용한 동탄성계수와 암상과의 상관성 분석)

  • Park, Chung-Hwa;Song, Moo-Young;Park, Jong-Oh
    • Journal of the Korean earth science society
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    • v.23 no.6
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    • pp.507-513
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    • 2002
  • To delineate the relationship between dynamic elastic modulus and lithologies, suspension PS logging was applied to Yuseong granite, Paldang banded gneiss, and Sabuk sedimentary rock. P and S wave velocities were also measured for these lithologies. In addition, uniaxial strength and Poisson’s ratio were measured in a laboratory for Yuseong granite and Paldang banded gneiss. In laboratory measurements, P and S wave velocities in Paldang banded gneiss were higher than those in Yuseong granite whereas Poisson’s ratio in Paldang banded gneiss was lower than that in Yuseong granite. This implies that P and S wave velocities correlate reversely with Poisson’s ratio. The dynamic Young modulus obtained from suspension PS logging was high compared to the dynamic bulk modulus and the dynamic shear modulus.

The Abnormal Groundwater Changes as Potential Precursors of 2016 ML5.8 Gyeongju Earthquake in Korea (지하수위 이상 변동에 나타난 2016 ML5.8 경주 지진의 전조 가능성)

  • Lee, Hyun A;Hamm, Se-Yeong;Woo, Nam C.
    • Economic and Environmental Geology
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    • v.51 no.4
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    • pp.393-400
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    • 2018
  • Despite some skeptical views on the possibility of earthquake prediction, observation and evaluation of precursory changes have been continued throughout the world. In Korea, the public concern on the earthquake prediction has been increased after 2016 $M_L5.8$ and 2017 $M_L5.4$ earthquakes occurred in Gyeongju and Pohang, the southeastern part in Korea, respectively. In this study, the abnormal increase of groundwater level was observed before the 2016 $M_L5.8$ Gyeongju earthquake in a borehole located in 52 km away from the epicenter. The well was installed in the Yangsan fault zone, and equipped for the earthquake surveillance. The abnormal change in the well would seem to be a precursor, considering the hydrogeological condition and the observations from previous studies. It is necessary to set up a specialized council to support and evaluate the earthquake prediction and related researches for the preparation of future earthquake hazards.

Detection of formation boundaries and permeable fractures based on frequency-domain Stoneley wave logs

  • Saito Hiroyuki;Hayashi Kazuo;Iikura Yoshikazu
    • Geophysics and Geophysical Exploration
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    • v.7 no.1
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    • pp.45-50
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    • 2004
  • This paper describes a method of detecting formation boundaries, and permeable fractures, from frequency-domain Stoneley wave logs. Field data sets were collected between the depths of 330 and 360 m in well EE-4 in the Higashi-Hachimantai geothermal field, using a monopole acoustic logging tool with a source central frequency of 15 kHz. Stoneley wave amplitude spectra were calculated by performing a fast Fourier transform on the waveforms, and the spectra were then collected into a frequency-depth distribution of Stoneley wave amplitudes. The frequency-domain Stoneley wave log shows four main characteristic peaks at frequencies 6.5, 8.8, 12, and 13.3 kHz. The magnitudes of the Stoneley wave at these four frequencies are affected by formation properties. The Stoneley wave at higher frequencies (12 and 13.3 kHz) has higher amplitudes in hard formations than in soft formations, while the wave at lower frequencies (6.5 and 8.8 kHz) has higher amplitudes in soft formations than in hard formations. The correlation of the frequency-domain Stoneley wave log with the logs of lithology, degree of welding, and P-wave velocity is excellent, with all of them showing similar discontinuities at the depths of formation boundaries. It is obvious from these facts that the frequency-domain Stoneley wave log provides useful clues for detecting formation boundaries. The frequency-domain Stoneley wave logs are also applicable to the detection of a single permeable fracture. The procedure uses the Stoneley wave spectral amplitude logs at the four frequencies, and weighting functions. The optimally weighted sum of the four Stoneley wave spectral amplitudes becomes almost constant at all depths, except at the depth of a permeable fracture. The assumptions that underlie this procedure are that the energy of the Stoneley wave is conserved in continuous media, but that attenuation of the Stoneley wave may occur at a permeable fracture. This attenuation may take place at anyone of the four characteristic Stoneley wave frequencies. We think our multispectral approach is the only reliable method for the detection of permeable fractures.

Performance Evaluation and Economic Estimation of Ground Source Heat Pump Cooling and Heating System (지열 냉난방 시스템의 성능 및 경제성 평가)

  • Lim Hyo Jae;Song Yoon Seok;Kong Hyoung Jin;Park Seong Koo
    • Journal of Energy Engineering
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    • v.13 no.4
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    • pp.296-300
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    • 2004
  • Performance evaluation and economic estimation were conducted on the water to water GSHP (Ground Source Heat Pump) installed in existing building. Ground heat exchanger was a closed vertical loop type and sized to be 5 boreholes and 100m depth per borehole. Operation efficiency of the system shows that, COP increased from 3.0 to 4.2 with entering water temperature in heating operation, however, COP decreased from 5.0 to 3.7 in cooling operation. Economic estimation was analyzed by LCC (Life Cycle Cost) method and it showed that GSHP could save 68% of cost compare to the conventional oil source. Thus, despite of the large amount of initial cost, GSHP has a economic advantage to the other energy sources.