Interpretation of a Long-Term In Situ Borehole Test in a Deep Salt Formation (1984)

Research Article| February 01, 1984 Interpretation of a Long-Term In Situ Borehole Test in a Deep Salt Formation GABRIEL FERNANDEZ; GABRIEL FERNANDEZ Visiting Assistant Professor 1Department of Civil Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801 Search for other works by this author on: GSW Google Scholar A. J. HENDRON A. J. HENDRON Professor 1Department of Civil Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801 Search for other works by this author on: GSW Google Scholar Author and Article Information GABRIEL FERNANDEZ Visiting Assistant Professor 1Department of Civil Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801 A. J. HENDRON Professor 1Department of Civil Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801 Publisher: Association of Environmental & Engineering Geologists First Online: 02 Mar 2017 Online ISSN: 1558-9161 Print ISSN: 1078-7275 © 1984 Association of Engineering Geologists Environmental & Engineering Geoscience (1984) xxi (1): 23–38. https://doi.org/10.2113/gseegeosci.xxi.1.23 Article history First Online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation GABRIEL FERNANDEZ, A. J. HENDRON; Interpretation of a Long-Term In Situ Borehole Test in a Deep Salt Formation. Environmental & Engineering Geoscience 1984;; xxi (1): 23–38. doi: https://doi.org/10.2113/gseegeosci.xxi.1.23 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyEnvironmental & Engineering Geoscience Search Advanced Search Abstract Long-term in situ measurements of volume change were carried out in a borehole test drilled in a salt formation 6,000 ft (1,850 m) deep. Well closures were monitored through a total period of 11 months. Three different pressures equal to 3,000 psi (20.7 MPa), 2,200 psi (15.2 MPa), and 1,300 psi (9.0 MPa) were induced in the well; each pressure level was maintained constant for an approximate period of 3½ months while well closures were measured on a daily basis.Test measurements indicated rather conclusively that steady-state creep does not develop around the well. Therefore a time-hardening expression like the power law will represent the creep phenomena of salt better than other empirical relationships that include “steady-state creep” terms. Test measurements also indicate that the decelerating of creep deformations around the opening depended on the magnitude of the shear stress level applied to the salt mass (difference between the overburden pressure and the internal pressure of the well). Thus the parameter n in the empirical power law is not a constant for all stress levels; the magnitude of n is larger for higher shear stress levels.A finite element analysis was carried out to simulate the behavior of the salt mass around the borehole opening. The power law was used as the material creep model, and creep parameters obtained from test measurements were used in the analysis. The results from this analysis reproduced fairly closely the behavior of the salt materials measured in the test. Finally, a non-dimensional analysis of the power law relationship, resulted in a definition of constant parameter K, which turned out to be dependent on the time units used in the power law equation. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.