Chevron U.s.a. Inc.

Los Alamos National Security, LLC

University of California

James A Tencate

Paul Allan Johnson

Robert A Guyer

Cung Khac Vu

Pierre-Yves Le Bas

Christopher Hugh Skelt

Kurt Nihei

Denis P Schmitt

Cung Vu

Paul A Johnson

Robert Guyer

Christopher Skelt

Koen E A Van Den Abeele

In some aspects of the disclosure, a method and an apparatus is disclosed for investigating material surrounding the borehole. The method includes generating a first low frequency acoustic wave within the borehole, wherein the first low frequency acoustic wave induces a linear and a nonlinear response in one or more features in the material that are substantially perpendicular to a radius of the borehole; directing a first sequence of high frequency pulses in a direction perpendicularly with respect to the longitudinal axis of the borehole into the material contemporaneously with the first acoustic wave; and receiving one or more second high frequency pulses at one or more receivers positionable in the borehole produced by an interaction between the first sequence of high frequency pulses and the one or more features undergoing linear and nonlinear elastic distortion due to the first low frequency acoustic wave to investigate the material surrounding the borehole

Device and method for imaging of non-linear and linear properties of formations surrounding a borehole

In some aspects of the disclosure, a method and an apparatus is disclosed for investigating material surrounding the borehole. The method includes generating within a borehole an intermittent low frequency vibration that propagates as a tube wave longitudinally to the borehole and induces a nonlinear response in one or more features in the material that are substantially perpendicular to a longitudinal axis of the borehole; generating within the borehole a sequence of high frequency pulses directed such that they travel longitudinally to the borehole within the surrounding material; and receiving, at one or more receivers positionable in the borehole, a signal that includes components from the low frequency vibration and the sequence of high frequency pulses during intermittent generation of the low frequency vibration, to investigate the material surrounding the borehole.

In some aspects of the disclosure, a method for creating three-dimensional images of non-linear properties and the compressional to shear velocity ratio in a region remote from a borehole using a conveyed logging tool is disclosed. In some aspects, the method includes arranging a first source in the borehole and generating a steered beam of elastic energy at a first frequency; arranging a second source in the borehole and generating a steerable beam of elastic energy at a second frequency, such that the steerable beam at the first frequency and the steerable beam at the second frequency intercept at a location away from the borehole; receiving at the borehole by a sensor a third elastic wave, created by a three wave mixing process, with a frequency equal to a difference between the first and second frequencies and a direction of propagation towards the borehole; determining a location of a three wave mixing region based on the arrangement of the first and second sources and on properties of the third wave signal; and creating three-dimensional images of the non-linear properties using data recorded by repeating the generating, receiving and determining at a plurality of azimuths, inclinations and longitudinal locations within the borehole. The method is additionally used to generate three dimensional images of the ratio of compressional to shear acoustic velocity of the same volume surrounding the borehole.

System and method to create three-dimensional images of non-linear acoustic properties in a region remote from a borehole

System and method to estimate compressional to shear velocity (VP/VS) ratio in a region remote from a borehole

Components with defects are identified from the response to strains applied at acoustic and ultrasound frequencies. The relative resonance frequency shift &verbar;&Dgr;&fnof;/&fnof;,&verbar;, is determined as a function of applied strain amplitude for an acceptable component, where &fnof;,is the frequency of the resonance peak at the lowest amplitude of applied strain and &Dgr;&fnof; is the frequency shift of the resonance peak of a selected mode to determine a reference relationship. Then, the relative resonance frequency shift &verbar;&Dgr;&fnof;/&fnof;,is determined as a function of applied strain for a component under test, where fo &fnof;,the frequency of the resonance peak at the lowest amplitude of applied strain and &Dgr;&fnof; is the frequency shift of the resonance peak to determine a quality test relationship. The reference relationship is compared with the quality test relationship to determine the presence of defects in the component under test.

Resonant nonlinear ultrasound spectroscopy

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Los Alamos, NM, United States of America

James A Tencate