Directional P-wave Remote Acoustic Imaging in an Acoustically Slow Formation
Zhoutuo Wei1, Hua Wang2, *, Xiaoming Tang3, Chunxi Zhuan3
Identifiers and Pagination:Year: 2015
First Page: 333
Last Page: 343
Publisher Id: TOPEJ-8-333
Article History:Received Date: 3/11/2014
Revision Received Date: 23/12/2014
Acceptance Date: 23/6/2015
Electronic publication date: 19/8/2015
Collection year: 2015
open-access license: This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International Public License (CC-BY 4.0), a copy of which is available at: https://creativecommons.org/licenses/by/4.0/legalcode. This license permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Directional P-wave remote acoustic imaging in an acoustically slow formation is discussed to improve dipole remote acoustic applications. In this paper, we start from the fundamental radiation, reflection and reception theory of a borehole dipole source. We then simulate the elastic wavefield radiation, reflection and reception generated by a borehole dipole source in an acoustically slow formation, and analyze their similarities and differences of the far-field radiation directionality of a borehole dipole-generated P-wave and monopole-generated P-wave. We demonstrate its sensitivity and feasibility in conjunction with a numerical simulation of P-wave remote acoustic imaging. The analytical results show that the dipole-generated P-wave has obvious reflection sensitivity and it can be utilized for reflection imaging and determination of the reflector azimuth. Based on the theoretical analysis above, a field example is used to demonstrate these characteristics and the application effectiveness of dipole-generated P-wave imaging and monopole-generated P-wave imaging. The results substantiate that dipole-generated P-wave has highly reflected amplitude and obvious azimuth sensitivity in an acoustically slow formation, providing an important supplement for dipole-generated S-wave remote acoustic imaging.