Recent Study and Modeling of Nonlinear Acoustic Processes in a Layered Nonlinear Medium with a Porous Fluid-Saturated Inclusion of a Hierarchical Type

Abstract

Problem statement: The results of study of seism acoustic emission arising in a porous two-phase geological environment under acoustic influence are presented. Acoustic emission arising in reservoirs of oil fields using well observations is considered. The main feature of acoustic emission is a reflection of stress relaxation and high sensitivity to external influences. The regularity of the emission processes of acoustic emission, which manifests itself in the form of discrete spectra of signals similar to oscillations of nonlinearly coupled oscillators, is shown. Spectra have special characteristics for each type of rock.

Applied Method and Design: An algorithm for modeling the process of resonant acoustic response of a porous fluid-saturated reservoir of a hierarchical structure to an acoustic frequency excitation located in an elastic N-layer medium and having plastic properties is written. That algorithm is developed as an iterative process for solution integral and integral-differential equations. The frequencies that are parameters of the direct problem are used from the spectra of observed data of acoustic emission in the oil wells.

Typical Results: For the first time it had been found the relation between resonant frequencies of the acoustic emission, which these values had been used in the algorithm of modeling acoustic processes in fluid saturated nonlinear plastic environment.

Concluding Note(Practical Value/Implications): The analysis of these emission processes can serve as a source of information about the filtration-capacitive properties of productive reservoirs of a porous type with a hierarchical structure. It by practical data of oil fields of Western Siberia.