Improved Description of the Acoustic Wave Parameters – Pressure Relations with New Double Relaxation Models
A. Kiss, D.O.B.N. Nuamah and M. Dobróka
Event name: 24th European Meeting of Environmental and Engineering Geophysics
Session: New Technologies, Developments and Research Trends A & Modelling, Inversion and Data-processing in Near Surface Geophysics D
Publication date: 09 September 2018
Info: Extended abstract, PDF ( 535.84Kb )
Price: € 20
The acoustic geophysical measurements are important not only for deep surveys such as HC exploration but for shallow investigation as well. Geotechnical, engineering geophysical problems often need information about acoustic velocities of near surface region and other parameters, f.e., the dynamic elastic moduli can be estimated based on them. It is well known that pressure influences the physical parameters, therefore models are needed to explore the relation between them. In this paper, our previously introduced Single Relaxation Models describing the pressure dependence of acoustic velocities and quality factors are further developed. The new rock physical models are considering two physical mechanisms (closure of pore volume or microcracks or friction on grain boundaries etc.) playing role in the pressure dependence of acoustic wave absorption-dispersion characteristics. The model equations for the velocities and the quality factors contain 5-5 model parameters, that can be estimated in quality-checked inversion procedure. After the determination of model parameters, the velocities and quality factors can be calculated for any pressure. The model’s applicability was tested on laboratory data sets. In this paper, the results obtained on a wet coal sample are presented and compared to the results of the old SRM. The improvement can be clearly seen.