Patent ID: 8345509
Filing Date: 2013-01-01
Classification: G01V

Abstract:
1. A method for creating three-dimensional images of non-linear properties in a region remote from a borehole using a conveyed logging tool, the method comprising: arranging a first source in the borehole and generating elastic energy at a first frequency; arranging a second source in the borehole and generating elastic energy at a second frequency, wherein the elastic energy at the first and the second frequency intersect at a mixing zone located away from the borehole; receiving, by an array of sensors, at the borehole a third elastic wave, with a frequency equal to a difference between the first and second frequencies and a direction of propagation towards the borehole created by a three wave non-collinear mixing process in a non-linear mixing zone; identifying a location of the three wave mixing zone based on the arrangement of the first and the second sources, the direction of the third wave and selection rules governing non-collinear mixing in acoustically non-linear media; and creating three-dimensional images of the non-linear properties using data recorded by repeating the generating, receiving and identifying at a plurality of azimuths, inclinations and longitudinal locations of the first source or the second source, or both within the borehole.