In-situ holographic elastic moduli measurements from boreholes
Abstract
We have developed a unique technique employing optical holography to measure the static Young's modulus (E) from a borehole. In the experiment, a known point force induces micron scale displacements on the borehole wall which are recorded by a double-exposure hologram. Raw data consist of dark fringes superimposed on the three-dimensional image whose pattern is modeled to find E directly. In the laboratory, the holographic technique determined E on rock and metal samples to an uncertainty better than 10 percent. For example, double exposure holograms of a saw-cut sample of dolomitic marlstone gave an E of 16.8 ± 2.8 GPa in agreement with 17.2 ± 2.0 GPa predicted by published density-modulus relationships. Field tests of a holographic tool in a horizontal mine pillar borehole gave in-situ Es which range from 26.9 to 36.0 GPa. Although these data could be interpreted as localized elastic heterogeneity within the rock mass, elastic anisotropy of the rock is a possible explanation for this variation.
Additional Information
© 1989 Society of Exploration Geophysicists. Presented at the 56th Annual International Meeting, Society of Exploration Geophysicists. Manuscript received by the Editor October 2, 1987; revised manuscript received September 12, 1988. The authors wish to thank Tom Nolan, Bridget Jensen, Epaprodito Gelle, Michael Long, William Barber, Wayne Miller, Gunther Haehn, and Dick Wickes for assistance in the field and laboratory. Douglas Schmitt greatly appreciates support from the Alberta Heritage Scholarship Fund from 1984 to 1986. This research was funded by grants from Schlumberger Technical Corporation, Sun Oil Corporation, and the Department of Energy (DE-FG03-85ER13422). Contribution 4523, Division of Geological and Planetary Sciences, California Institute of Technology.Attached Files
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Additional details
- Eprint ID
- 51097
- Resolver ID
- CaltechAUTHORS:20141031-073217994
- Schlurnberger Technical Corporation
- Sun Oil Co.
- Department of Energy (DOE)
- DE-FG03-85ER13422
- Created
-
2014-10-31Created from EPrint's datestamp field
- Updated
-
2021-11-10Created from EPrint's last_modified field
- Other Numbering System Name
- Caltech Division of Geological and Planetary Sciences
- Other Numbering System Identifier
- 4523