Abstract: A method of identifying a material and/or condition of a material in a borehole is described, together with related apparatus. The material may either be between first and second tubulars or between a first tubular and a wall of the borehole. The method may include providing a reference quality factor (Qreference) for one or more known materials in one or more known conditions and measuring a downhole quality factor (Qmeasured) of the material and/or material condition to be identified. A spectral ratio ?=(Qmeasured/Qreference) may then be computed for one or more known materials under one or more known conditions followed by an analysis of the spectral ratios to identify the material and/or condition of the material in the borehole.

Abstract: A downhole installation comprises: a first pipe layer 8, a second pipe layer 10 about the first pipe layer 8, an annulus 12 between the first pipe layer 8 and the second pipe layer, and a geological formation outside of the second pipe layer 10.

Abstract: A downhole installation includes a first pipe layer, a second pipe layer about the first pipe layer, an annulus between the first and second pipe layers, and a geological formation outside of the second pipe layer. A method for evaluating the downhole installation includes: exciting a flexural wave in the first pipe layer using an angled acoustic transmitter; receiving third interface echo data using a plurality of angled acoustic receivers at different locations along the longitudinal extent of the pipe layers; generating acoustic resonance across the thickness of the first and second pipe layers by use of full waveform excitation; receiving the acoustic response wave field generated by the full waveform; identifying a suitable component of the acoustic response wave field; determining if the material outside the second pipe layer is fluid or solid; and analyzing the third interface echo data to thereby evaluate material conditions in the annulus.

Abstract: A method of identifying a material and/or condition of a material in a borehole is described, together with related apparatus. The material may either be between first and second tubulars or between a first tubular and a wall of the borehole. The method may include providing a reference quality factor (Qreference) for one or more known materials in one or more known conditions and measuring a downhole quality factor (Qmeasured) of the material and/or material condition to be identified. A spectral ratio ?=(Qmeasured/Qreference) may then be computed for one or more known materials under one or more known conditions followed by an analysis of the spectral ratios to identify the material and/or condition of the material in the borehole.

Abstract: A downhole installation comprises: a first pipe layer 8, a second pipe layer 10 about the first pipe layer 8, an annulus 12 between the first pipe layer 8 and the second pipe layer, and a geological formation out-side of the second pipe layer 10.

Abstract: A downhole installation comprises: a first pipe layer 8, a second pipe layer 10 about the first pipe layer 8, an annulus 12 between the first pipe layer 8 and the second pipe layer, and a geological formation outside of the second pipe layer 10.

Abstract: An acoustic measurement tool comprises a transmitter for generating acoustic signals and at least one acoustic receiver spaced from the transmitter and configured to receive an acoustic signal, generated by the transmitter, and which has encountered a medium of interest. Moreover, at least one acoustic reference receiver is located adjacent the transmitter and is configured to receive an acoustic signal, generated by the transmitter, prior to the acoustic signal encountering the medium of interest.

Abstract: An acoustic measurement tool comprises a transmitter for generating acoustic signals and at least one acoustic receiver spaced from the transmitter and configured to receive an acoustic signal, generated by the transmitter, and which has encountered a medium of interest. Moreover, at least one acoustic reference receiver is located adjacent the transmitter and is configured to receive an acoustic signal, generated by the transmitter, prior to the acoustic signal encountering the medium of interest.