Measurement of in-situ stress in salt and rock using NQR techniques

Technical Report · Mon Dec 01 00:00:00 EST 1980

DOI:https://doi.org/10.2172/6458652· OSTI ID:6458652

Schempp, E; Hirschfeld, T; Klainer, S

A discussion of how stress and strain affect the quantities which can be measured in an NQR experiment shows that, for stresses of the magnitude to be expected at depths up to about 10,000 feet, quadrupole coupling constants will fall in the range of 1 to 10 kHz for both the sodium and chloride ions in NaCl. The most promising system involves pulsed nuclear double resonance detection; and alterative is to observe the quadrupolar splitting of the NMR signal. Choices to be made in the measurement and mapping techniques are discussed. The well-known perturbation of the homogenous stress field in the neighborhood of a borehole is shown to be advantageous from the point of view of obtaining directional information on the stress. Construction and operation of a borehole stress sensor are considered. The NQR technique seems feasible for measuring the magnitude and direction of underground stress with a resolution of about 25 psi, or 2.5% at 1000 psi. Downhole instrumentation suitable for in-situ determinations of stress appears within the state of the art. Additional tasks required on the project are identified.

• Research Organization: Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 6458652
• Report Number(s): LBL-11895; TRN: 81-008928
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES
ROCKS
STRESSES
SALT DEPOSITS
MEASURING METHODS
BOREHOLES
COUPLING
FEASIBILITY STUDIES
NUCLEAR QUADRUPOLE RESONANCE
SODIUM CHLORIDES
UNDERGROUND
ALKALI METAL COMPOUNDS
CAVITIES
CHLORIDES
CHLORINE COMPOUNDS
GEOLOGIC DEPOSITS
HALIDES
HALOGEN COMPOUNDS
LEVELS
RESONANCE
SODIUM COMPOUNDS
580300* - Mineralogy
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