Abstract: A method for providing a location of equipment external to a downhole pipe within a wellbore by detecting or generating magnetic or electromagnetic fields within the downhole pipe and measuring the magnetic/electromagnetic field disturbances caused from one or more magnetic generating entities. The magnetic generating entities are detected from the magnetic/electromagnetic field disturbances and the location of the pipe external equipment is determined based upon the magnetic/electromagnetic field disturbances caused from the magnetic generating entities. In another embodiment, an apparatus that comprises at least one pipe external equipment coupled to a downhole pipe within the wellbore, and at least one magnetic field generating entities coupled relatively close or at a known geometric distance to the at least one pipe external equipment. The magnetic field generating entities are coupled to at least one pipe external equipment using a fastening component or installed in the downhole pipe or pipe mandrel.

Abstract: Acoustic waves from a controllable downhole acoustic source in a cased borehole are focused into a region of an earth formation. A hydrophone is used to monitor acoustic signals for onset of cavitation. The estimated pressure from the source in the focus region provides an estimate of formation pore pressure.

Abstract: Evaluating casing thickness by inducing SH0 and SH1 modes of a shear wave in the casing. The SH0 group velocity and SH1 mode group velocity (Vg) are measured and the measured SH0 mode group velocity is assigned as the tubular material shear velocity (Vs). A shear wave wavelength ? from the ratio of SH0 mode frequency (fo) and the measured SH0 group velocity is estimated. The tubular thickness (d) is estimated from the estimated shear wave wavelength ?. The transmitter can be calibrated to operate at an optimum frequency.

Abstract: Acoustic waves from a controllable downhole acoustic source in a cased borehole are focused into a region of an earth formation. A hydrophone is used to monitor acoustic signals for onset of cavitation. The estimated pressure from the source in the focus region provides an estimate of formation pore pressure.

Abstract: Evaluating casing thickness by inducing SH0 and SH1 modes of a shear wave in the casing. The SH0 group velocity and SH1 mode group velocity (Vg) are measured and the measured SH0 mode group velocity is assigned as the tubular material shear velocity (Vs). A shear wave wavelength ? from the ratio of SH0 mode frequency (fo) and the measured SH0 group velocity is estimated. The tubular thickness (d) is estimated from the estimated shear wave wavelength ? The transmitter can be calibrated to operate at an optimum frequency.

Abstract: A combined electromagnetic acoustic transducer (EMAT) is disclosed adapted to generate both SH-type acoustic waves and LAMB-type acoustic waves in a conductive casing, surroundings of which are to be analyzed. The transducer comprises one magnet assembly and two RF coils implemented as multi-layer printed circuit board. Each coil is used to generate or receive acoustic signals of one wave type. Compared to using two single-wave-type transducers the combined EMAT significantly reduces total attraction force to the casing and, correspondingly, simplifies mechanics of the measurement tool. It is emphasized that this abstract is provided to comply with the rules requiring an abstract which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.

Abstract: The method and apparatus of the present invention provides for inducing and measuring shear waves within a wellbore casing to facilitate analysis of wellbore casing, cement and formation bonding. An acoustic transducer is provided that is magnetically coupled to the wellbore casing and is comprised of a magnet combined with a coil, where the coil is attached to an electrical current. The acoustic transducer is capable of producing and receiving various waveforms, including compressional waves, shear waves, Rayleigh waves, and Lamb waves as the tool traverses portions of the wellbore casing.