RUSSIAN JOURNAL OF EARTH SCIENCES VOL. 5, NO. 4, PAGES 299–306, doi:10.2205/2003ES000130, 2003

Anisotropy of the rock drill core elastic properties at uniaxial loading

The Borok Geophysical Observatory of the United Institute of Physics of the Earth, Russian Academy of Sciences, Borok, Jaroslavl' region, Russia

Abstract

[1]  Application of three-component recording transducers for laboratory investigations was restrained for a long time because of the manufacturing complexity. Ingenious three-component piezoelectric transducers were used in this work for recording the acoustic emission signals. At the same time these transducers made it possible to reproduce a wave pattern which occurs in a sample. A real medium, in the oil-water-saturated reservoir zones especially, is complicated and diverse from the point of view of the lithologic composition, porosity nature, graininess and presence of various inclusions. Anisotropy of the core elastic properties at the uniaxial loading was studied in this work. A comparative analysis was made of the wave patterns, which were recorded by ultrasonic transducers of different types. Results of the work may be used for a further development of the laboratory methods for investigation of the elastic properties of materials. The effect of a stable polarization of the ultrasonic wave coinciding with orientation of the weakened zone obtained, allows to use it for determination of the direction of the preferred orientation of the joints.

Received 2 September 2003; published 9 September 2003.

Keywords: anisotropy, core elastic properties, transducers, lithologic composition, porosity nature, ultrasonic transducers.