• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.16 no.1 s.106
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• pp.19-26
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• 2006

The test blasts were carried out by detonating some single blastholes at two upper sites of the underground storage cavern for the crude oil. One was performed at the entrance site of the construction tunnel and the other at the middle area of the underground storage cavern. Based on the blast-induced nitration measured by the test blasts, we suggested the propagation equations of blasting vibration that were capable of estimating the peak particle velocity. In addition, in order to assess the stability of the adjacent ground storage tank, we did the frequency analysis and the response spectrum analysis with the particle velocity-time history and the particle acceleration-time history that were measured by the test blast carried out on the entrance site of the construction tunnel. In result, it was predicted that the displacement on the highest part of the tank shell was less than the allowable displacement.

• Tunnel and Underground Space
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• v.18 no.1
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• pp.80-89
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• 2008

The influence of in-situ rock stress on the stability of an underground rock structure increases as the construction depth become deeper and the scale of a rock structure become larger. In general, hydraulic fracturing stress measurement has been performed in the surface boreholes of the target area at the design stage of an underground structure. However, for some areas where the high horizontal stresses were observed or where the overstressed conditions caused by topographical and geological factors are expected, it is desirable to conduct additional in-situ stress measurement in the underground construction site to obtain more detailed stress information for ensuring the stability of a rock structure and the propriety of current design. The study area was a construction site for the additional underground oil storage facility located in the south-east part of OO city, Jeollanam-do. Previous detailed site investigation prior to the design of underground structures revealed that the excessive horizontal stress field with the horizontal stress ratio(K) greater than 3.0 was observed in the construction area. In this study, a total of 13 hydraulic fracturing stress measurements was conducted in two boreholes drill from the two water tunnel sites in the study area. The investigation zone was from 180 m to 300 m in depth from the surface and all of the fracture tracing works were carried out by acoustic televiewer scanning. For some testing intervals at more than 200 m ind depth from surface, the high horizontal stress components the horizontal stress ratio(K) greater than 2.50 were observed. And the overall investigation results showed a good agreement with the previously performed test.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.11a
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• pp.479-484
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• 2005

The test blasts were carried out by detonating some single blastholes at two upper sites of the underground storage cavern the crude oil. One was performed at the entrance site of the construction tunnel and the other at the middle part of the underground storage cavern. Based on the blast-induced vibration measured by the test blasts, we suggested the propagation equations of blasting vibration that were capable of estimating the peak particle velocity. In addition, in order to assess the stability of the nearest ground storage tank, we did the frequency analysis and the response spectrum analysis with the particle velocity-time history and the particle acceleration-time history that were measured by the test blast carried out on the entrance site of the construction tunnel. In result, it was predicted that the displacement on the highest part of the tank shell was less than the allowable displacement.

• The Journal of Engineering Geology
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• v.12 no.1
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• pp.35-51
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• 2002

This study aims to establish the methodology for design of an optimum water curtain system of the unlined underground oil storage cavern satisfying the requirements of hydrodynamic performance in a volcanic terrain of the south coastal area. For the optimum water curtain system in the storage facility, the general characteristics of groundwater flow system in the site are quantitatively described, i.e. distribution of hydraulic gradients, groundwater inflow rate into the storage caverns, and hydrogeologic influence area of the cavern. In this study, numerical models such as MODFLOW, FracMan/MAFIC and CONNECTFLOW are used for calculating the hydrogeological stability parameters. The design of a horizontal water curtain system requires considering the distance between water curtain and storage cavern, spacing of the water curtain boreholes, and injection pressure. From the numerical simulations at different scales, the optimum water curtain systems satisfying the containment criteria are obtained. The inflow rates into storage caverns estimated by a continuum model ranged from about 120 m$^3$/day during the operation stage to 130~140m$^3$/day during the construction stage, whereas the inflow rates by a fracture network model are 80~175m$^3$/day. The excavation works in the site will generate the excessive decline of groundwater level in a main fracture zone adjacent to the cavern. Therefore, the vertical water curtain system is necessary for sustaining the safe groundwater level in the fracture zone.

• Tunnel and Underground Space
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• v.20 no.4
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• pp.233-240
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• 2010

Double Plug is constructed for preventing mixing of two different oils between two compartments in the underground oil storage cavern. And the gas and oil tightness of double plug is tested from the measurement of water leakage from double plug after the completion of double plug water filling. If water leakage is underestimated, it can increase construction cost and if water leakage is overestimated, it can increase operating cost. Therefore, optimum water leakage should be estimated to cut down the cost. In this study, hydraulic stability analysis was conducted to consider permeable properties of rock mass around double plugs and a water leak rate from double plug was estimated from the hydraulic stability analysis and case study. Finally, the reliability of estimation of water leak rate was proven by comparing estimated water leak rate with measured data.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.2 no.4
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• pp.33-38
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• 1982

A successful operation of underground oil storage cavern depends on water-tightness around cavern by groundwater. If water-tightness is not secured, gas bubbles would leak out and oil would migrate to an adjacent empty cavern. In this research an electrical analogy method was employed to study the influence of shape of cavern on gas leakage and the required natural groundwater level, relative oil level in two neighboring caverns and cavern spacing to prevent oil migration. The results show that gas leakage is prevented from a cavern with a ceiling of large curvature. The required values of factors to curtail the migration of oil are given on a graph.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.3 no.3
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• pp.87-94
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• 1983

The successful oil storage in the underground cavern is dependent on how to keep the water-tightness around the cavern by the groundwater. If the water-tightness is not secured, gas bubles will leak out and oil migrate to the adjacent empty cavern. An electrical analogy method was employed in studying the influences of the position of horizontal and vertical water curtains, the head of water curtain and the intervals of the cavern spacings and boreholes on the gas leakage and the oil migration into the adjacent empty cavern. The result shows that if the cavern spacing is narrow, the vertical water curtain should be established and if the cavern spacing is more than twice the cavern height, its establishment is not necessary. All the detailed factors required to prevent the oil migration are shown on graphs.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.1310-1311
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• 2003

Oil Field Geographical Information System (OFGIS) manages multiple spatial data, attribute data, and topographic data, which include almost every kind of ground info rmation and underground information. Subsystems managed by OFGIS include petroleum exploration subsystem (PESS), petroleum development and engineering subsystem (PDESS), petrochemical subsystem (PCSS), petroleum storage and transportation subsystem (PSTSS), petroleum sale subsystem (PSSS), etc. A basic OFGIS framework consists of oil field infrastructure coverage (OFIC), oil field specialized information coverage (OFSIC) and oil field synthesis and decision service coverage (OFSDSC). Basic function of OFGIS includes database management, geographic information management, spatial information processing and application.

• Tunnel and Underground Space
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• v.5 no.2
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• pp.123-133
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• 1995

A two dimensional visco-plastic finite element model capable of handling the multistep excavaton was developed for investigating the effect of excavation-support sequences on the behaviour of underground openings in the jointed rock mass. Ubiquitous joint pattern was considered in the model and joint properties in each set were assumed to be identical. Passive, fully-grouted rockbolts were considered in the model. Visco-plastic deformations of joints and rockbolts were assumed to be governed by Mohr-Coulomb and von Mises yield criteria, respectively. With the ability of removing elements, the model can von Mises yield criteria, respectively. With the ability of removing elements, the model can simulate the multi-step excavation-support sequences. The reliability of the model to the stability analysis for the underground excavation in practice was checked by simulating the behavior of underground crude oil storage caverns under construction.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1996.04a
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• pp.173-181
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• 1996

In this study, a stochastic finite element model is proposed with a view to consider the uncertainty of physical properties of rock mass in the analysis of structural behavior on underground caverns. Here, the Latin Hypercube Sampling technique, in which can makeup weak points of the Monte Carlo Simulation, is applied for the analysis of underground cavern. The validity of the newly developed computer program has been confirmed in terms of verification examples. And, the applicability of the program to the field has been tested in terms of the analysis of the underground oil storage cavern in korea.