Abstract: Methods and apparatus for automatic recognition of environmental parameters with azimuthally distributed transducers. For example, a toolstring is disposed in a cased portion of a borehole penetrating a subsurface formation. The toolstring comprises a module comprising azimuthally distributed acoustic transducers each operable to emit and receive acoustic signals. The module is operated to emit an acoustic signal into fluid surrounding the module in the casing and record data indicative of receipt, by a plurality of the transducers, of acoustic waveforms resulting from interaction of the emitted acoustic signal with the casing, including at least a non-specular diffraction head wave excited by a guided wave that is excited by diffraction of the acoustic signal propagating in the casing metal. Acoustic velocity of the guided wave in the casing metal is determined utilizing the recorded data and geometric parameters of the module.

Abstract: Methods including determining a measurement plan, having acoustic measurements, and lowering in a borehole penetrating a subsurface formation a toolstring having phased array modules. Each phased array module includes acoustic transducers operable to emit an acoustic excitation signal and receive an echo signal, as well as a programmable circuit for setting one or more variables of the phased array module. The phased array modules are configured, including programming the programmable circuit to set variables of the phased array modules according to the measurement plan. The acoustic measurements of the measurement plan are performed using the configured phased array modules. One or more of the formation, a casing disposed in the borehole, and/or an annulus between the casing and the formation are characterized using results of the performed acoustic measurements.

Abstract: A downhole tool having an acoustic transducer for downhole measurements. A backing is in contact with an inner surface of the transducer. A first structure is coupled to a first housing. A second structure is coupled to a second housing. A member includes first, second, and third portions. The first portion is coupled to the first structure. The second portion is coupled to the second structure. At least one of the first and second structures is coupled to the member and has a degree of freedom relative to the member. The third portion extends longitudinally through the backing between the first and second portions such that compressional forces on the first and second housings are transferred through the first and second structures and the backing. A canister contacts an outer surface of the transducer and exerts radial forces on the transducer when exposed to pressures higher than atmospheric pressure.

Abstract: A downhole tool having an acoustic transducer for downhole measurements. A backing is in contact with an inner surface of the transducer. A first structure is coupled to a first housing. A second structure is coupled to a second housing. A member includes first, second, and third portions. The first portion is coupled to the first structure. The second portion is coupled to the second structure. At least one of the first and second structures is coupled to the member and has a degree of freedom relative to the member. The third portion extends longitudinally through the backing between the first and second portions such that compressional forces on the first and second housings are transferred through the first and second structures and the backing. A canister contacts an outer surface of the transducer and exerts radial forces on the transducer when exposed to pressures higher than atmospheric pressure.

Abstract: Methods and apparatus for automatic recognition of environmental parameters with azimuthally distributed transducers. For example, a toolstring is disposed in a cased portion of a borehole penetrating a subsurface formation. The toolstring comprises a module comprising azimuthally distributed acoustic transducers each operable to emit and receive acoustic signals. The module is operated to emit an acoustic signal into fluid surrounding the module in the casing and record data indicative of receipt, by a plurality of the transducers, of acoustic waveforms resulting from interaction of the emitted acoustic signal with the casing, including at least a non-specular diffraction head wave excited by a guided wave that is excited by diffraction of the acoustic signal propagating in the casing metal. Acoustic velocity of the guided wave in the casing metal is determined utilizing the recorded data and geometric parameters of the module.

Abstract: A downhole tool having an acoustic transducer for downhole measurements. A backing is in contact with an inner surface of the transducer. A first structure is coupled to a first housing. A second structure is coupled to a second housing. A member includes first, second, and third portions. The first portion is coupled to the first structure. The second portion is coupled to the second structure. At least one of the first and second structures is coupled to the member and has a degree of freedom relative to the member. The third portion extends longitudinally through the backing between the first and second portions such that compressional forces on the first and second housings are transferred through the first and second structures and the backing. A canister contacts an outer surface of the transducer and exerts radial forces on the transducer when exposed to pressures higher than atmospheric pressure.

Abstract: Methods including determining a measurement plan, having acoustic measurements, and lowering in a borehole penetrating a subsurface formation a toolstring having phased array modules. Each phased array module includes acoustic transducers operable to emit an acoustic excitation signal and receive an echo signal, as well as a programmable circuit for setting one or more variables of the phased array module. The phased array modules are configured, including programming the programmable circuit to set variables of the phased array modules according to the measurement plan. The acoustic measurements of the measurement plan are performed using the configured phased array modules. One or more of the formation, a casing disposed in the borehole, and/or an annulus between the casing and the formation are characterized using results of the performed acoustic measurements.