| US 7,463,551 B2 | ||
| Method of generating directional low frequency acoustic signals and reflected signal detection enhancements for seismic while drilling applications | ||
| James V. Leggett, III, Houston, Tex. (US); and Vladimir Dubinsky, Houston, Tex. (US) | ||
| Assigned to Baker Hughes Incorporated, Houston, Tex. (US) | ||
| Filed on Oct. 01, 2007, as Appl. No. 11/865,590. | ||
| Application 11/865590 is a division of application No. 10/640240, filed on Aug. 13, 2003, granted, now 7,301,852. | ||
| Prior Publication US 2008/0019216 A1, Jan. 24, 2008 | ||
| Int. Cl. G01V 1/40 (2006.01); G01V 1/46 (2006.01) | ||
| U.S. Cl. 367—32 [367/25; 367/86; 181/102] | 12 Claims |
| 1. A method of using an acoustic logging tool conveyed in a borehole in an earth formation on a bottom hole assembly (BHA)
for determining a characteristic of the formation, the BHA including a conduit for conveying a drilling fluid from a surface
location to a drillbit on the bottom hole assembly, the method comprising:
(a) using a primary acoustic source in said BHA for;
(I) generating an acoustic signal in a fluid flow path selected from (i) said conduit, and (ii) an annulus between said BHA
and said earth formation; and
(II) radiating a first acoustic signal into the earth formation;
(b) using a secondary acoustic source for producing a radiated second acoustic signal into the earth formation in response
to the acoustic signal in the fluid flow path; and
(c) recording a signal produced by interaction of said radiated first signal and the radiated second signal with said earth
formation.
|