Reliability analysis of hydrologic containment of underground storage of liquefied petroleum gas
Journal
Tunnelling and Underground Space Technology
Journal Volume
79
Pages
12-26
Date Issued
2018
Author(s)
Abstract
The objectives of this paper are (1) to introduce a numerical first order method to calculate the gas containment reliability within a heterogeneous, two-dimensional, unlined rock caverns (URCs), and (2) to suggest a strategy for improving the gas containment reliability. In order to achieve these goals, we first analyzed the spatial variability of saturated hydraulic conductivity (Ks) at a field site. We then conducted deterministic simulations to demonstrate the importance of heterogeneity of Ks in the analysis of gas tightness performance of URCs. Considering the uncertainty of the heterogeneity in the real world situations, we subsequently developed a numerical first order method (NFOM) to determine the gas tightness reliability at crucial locations of URCs. Using the NFOM, the effect of spatial variability of Ks on gas tightness reliability was investigated. Results show that as variance or spatial structure anisotropy of Ks increases, most of the gas tightness reliability at crucial locations reduces. Meanwhile, we compare the results of NFOM with those of Monte Carlo simulation, and we find the accuracy of NFOM is mainly affected by the magnitude of the variance of Ks. At last, for improving gas containment reliability at crucial locations at this study site, we suggest that vertical water-curtain holes should be installed in the pillar rather than increasing density of horizontal water-curtain boreholes. © 2018 Elsevier Ltd
Subjects
Boreholes; Caves; Hydraulic conductivity; Intelligent systems; Location; Monte Carlo methods; Numerical analysis; Numerical methods; Reliability; Underground gas storage; Deterministic simulation; Hydrologic containment; Petroleum gas; Real world situations; Rock cavern; Saturated hydraulic conductivity; Spatial variability; Underground storage; Reliability analysis; accuracy assessment; borehole; cavern; containment; hydraulic conductivity; liquefied petroleum gas; Monte Carlo analysis; reliability analysis; underground storage
Publisher
Elsevier Ltd
Type
journal article