Estimation of groundwater aquifer formation-strength parameters from geophysical well logs: The southwestern coastal area of Yun-Lin, Taiwan

B. Z. Hsieh, G. V. Chilingar, M. T. Lu, Z. S. Lin

Research output: Contribution to journalArticlepeer-review

4 Citations (Scopus)

Abstract

The purpose of this study is to estimate groundwater aquifer formation-strength parameters including shear modulus, bulk modulus, Poisson's ratio, and Young's modulus by using geophysical well logs. A new dispersed-shale index equation was developed by using the natural gamma-ray log and the compensated formation density log to solve a confusing problem of the compaction factor setting in the calculation of sonic porosity for an unconsolidated groundwater aquifer. A useful Poisson's ratio estimation method was employed to estimate groundwater aquifer formation-strength parameters when shear-wave transit time data is lacking in groundwater wells. Hydrogeologic parameters are characterized in estimating formation-strength parameters. Five wells in the southwestern coastal area of Yun-Lin, Taiwan, were logged, and four shallow aquifers were identified from log-derived hydrogeologic characteristics less than 200 m in depth. The formation-strength parameters for aquifers between 310 and 500 m in depth were calculated in two wells because complete formation density and compressional-wave transit time data were available. The results of the aquifer's formation-strength parameters demonstrate that both shear modulus, ranging from 0.15 to 0.42*106 psi, and Young's modulus, ranging from 0.40 to 1.07*106 psi, increase with depth, whereas bulk compressibility, ranging from 1.2 to 2.6*10-6 psi -1, decreases with increasing depth.

Original languageEnglish
Pages (from-to)97-115
Number of pages19
JournalEnergy Sources, Part A: Recovery, Utilization and Environmental Effects
Volume29
Issue number2
DOIs
Publication statusPublished - 2007 Dec 1

All Science Journal Classification (ASJC) codes

  • Renewable Energy, Sustainability and the Environment
  • Nuclear Energy and Engineering
  • Fuel Technology
  • Energy Engineering and Power Technology

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