The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 01, 1992
Filed:
Jan. 02, 1991
Bob A Hardage, Austin, TX (US);
Western Atlas International, Inc., Houston, TX (US);
Abstract
A method for detecting the presences of fractures in a subsurface formation being penetrated by a drill bit during drilling. Teeth on the drill bit act as individual seismic sources, generating both shear wave energy and compressional wave energy. As the drill bit passes through a formation, the shear wave energy generated by the bit propagates along the formation in a waveguide mode between the adjacent formations. As the shear wave signal passes through a fractured zone of the formation, two shear wave signals are generated, each polarized in relationship to the orientation of the fractures in the formation. As the polarized signals propagate along the formation, secondary shear wave signals are generated which return to the surface and are detected by appropriate sensors. The sensors have a plurality of detectors in order to detect the polarity or direction of particle motion cuased by the polarized wave, providing information that a fracture zone exists in the subsurface.