Abstract: A method can include, using a downhole tool, acquiring ultrasonic echo data of a borehole, where the ultrasonic echo data include echoes representative of material and borehole geometry responsive to reflection of ultrasonic energy that has a wide-band frequency range; filtering the ultrasonic echo data using at least one selected filter for multi-band frequency filtering corresponding to different frequency ranges of the wide-band frequency range to generate filtered data; and processing the filtered data to generate attribute values representative of physical characteristics the material, the borehole geometry, or the material and the borehole geometry.

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: Methods for correcting eccentering effects on echoes detected from ultrasonic pulses emitted by a transducer of a downhole tool. Echo envelope amplitude, azimuth, and location for each echo is utilized to assess echo amplitude sensitivity to geometric and spatial characteristics of the downhole tool within the wellbore. Echo envelope amplitudes are corrected for eccentering effects based on the assessed sensitivity. A visual representation of the corrected echo envelope amplitudes is the generated. Also disclosed herein are tangible, non-transient, computer-readable media comprising instructions executable by a processor to carry out the methods, as well as systems including downhole tools and processing devices operable to carry out the methods.

Abstract: Systems and methods for determining a shear wave slowness may include emitting an emitted acoustic wave within a borehole from an acoustic tool. A return acoustic wave may be detected via one or more sensors. The return acoustic wave may be generated when the emitted acoustic wave interacts with a physical feature within the borehole. A signal may be generated that may be indicative of the return acoustic wave. The method may include evaluating the signal via a processor to determine a pseudo-Rayleigh mode slowness and calculating a shear wave slowness using an analytical relationship. The analytical relationship may include a mathematical correlation between the pseudo-Rayleigh mode slowness and the shear wave slowness. The analytical relationship may also include input parameters that are measured physical parameters of borehole properties.

Abstract: Example ultrasonic acoustic sensors for measuring formation velocities are disclosed herein. An example sensor includes a housing, a first transmitter carried by the housing, a second transmitter carried by the housing, and a receiver array carried by the housing and disposed between the first transmitter and the second transmitter. The first transmitter is disposed at a first angle relative to a surface the housing and the second transmitter is disposed at second angle relative to the surface the housing.

Abstract: Apparatus and methods for identifying drilling cuttings downhole by extracting an echo from a pulse-echo waveform acquired utilizing a downhole ultrasonic tool having an acoustic device. An energy before echo profile preceding the extracted echo is determined, and then the energy before echo profile is processed to remove effects associated with the acoustic device. A cutting is then identified from the processed energy before echo profile.

Abstract: Provided are an internal olefin sulfonate composition which shows excellent hue stability and excellent smell stability even when preserved for a long period of time, and a method for preserving an internal olefin sulfonate. The internal olefin sulfonate composition according to the present invention comprises an internal olefin sulfonate, one or more kinds of alkaline agents selected from among an alkali metal hydroxide and an alkaline earth metal hydroxide and water, wherein the content of the alkaline agents is 0.2 to 15 mmol inclusive per mol of the internal olefin sulfonate. The method according to the present invention for preserving an internal olefin sulfonate comprises mixing the internal olefin sulfonate at least with an alkaline agent to give a composition wherein the content of the alkaline agent is 0.2 to 15 mmol inclusive per mol of the internal olefin sulfonate.

Abstract: Example ultrasonic transducers for measuring formation velocities are disclosed herein. An example apparatus includes a housing and an acoustic transducer having a first surface and a second surface opposite the first surface. The acoustic transducer is at least partially disposed in the housing. The example apparatus includes a window supported by the housing. At least a portion of the first surface of the acoustic transducer is in contact with the window. The housing and the window are to form a fluid seal for the acoustic transducer.

Abstract: A downhole tool having a transmitter array with azimuthally spaced transmitters and receiver arrays with azimuthally spaced receivers. Methods of operation include transmitting an acoustic signal from an individual one of the transmitters, sensing an attribute of the acoustic signal with the receivers, and evaluating a characteristic of a portion of a downhole feature based on response signals generated by the first and second receivers. Each response signal is indicative of the acoustic signal attribute sensed by the corresponding receivers. This is repeated with different individual ones of the transmitters and receivers until the evaluated portions of the downhole feature collectively extend around a wellbore.

Abstract: Methods for correcting eccentering effects on echoes detected from ultrasonic pulses emitted by a transducer of a downhole tool. Echo envelope amplitude, azimuth, and location for each echo is utilized to assess echo amplitude sensitivity to geometric and spatial characteristics of the downhole tool within the wellbore. Echo envelope amplitudes are corrected for eccentering effects based on the assessed sensitivity. A visual representation of the corrected echo envelope amplitudes is the generated. Also disclosed herein are tangible, non-transient, computer-readable media comprising instructions executable by a processor to carry out the methods, as well as systems including downhole tools and processing devices operable to carry out the methods.

Abstract: A technique facilitates use of acoustic measurements to enable geo-steering during a well operation. A steerable well string is provided with acoustic systems used to collect data which is then processed to determine geo-steering inputs. In some applications, the well string may comprise a coiled tubing drilling tool. The coiled tubing drilling tool or other well string tool is combined with an azimuthally distributed pitch-catch micro-sonic sensor system and an azimuthally distributed ultrasonic pulse-echo transducer system. Data from these two systems is provided to a processing system which processes the data to determine, for example, real-time, geo-steering inputs. These inputs may then be used to more effectively steer the coiled tubing drilling tool or other well string tool.

Abstract: Systems, methods, and devices for evaluating proper cement installation in a well are provided. In one example, a method includes receiving acoustic cement evaluation data into a data processing system. The acoustic cement evaluation data derives from one or more acoustic downhole tools used over a depth interval in a well having a casing. The acoustic cement evaluation data includes sonic measurements and ultrasonic measurements. The method includes deriving a sonic-derived acoustic impedance Z(sonic) from the sonic measurements deriving an ultrasonic-derived acoustic impedance Z(ultrasonic) from the ultrasonic measurements comparing the Z(sonic) with respect to the Z(ultrasonic), and determining whether an annular fill behind the casing is well bonded, partially bonded, comprises wet microannulus, or comprises dry microannulus based on the comparison of the Z(sonic) with respect to the Z(ultrasonic).

Abstract: A method of model-based acoustic measurements for a wellbore comprises creating an interpretation chart of acoustic measurements by a downhole tool in a wellbore using a numerical modeling and performing an evaluation with respect to the wellbore based on the interpretation chart.

Abstract: Methods, apparatus, systems, and articles of manufacture are disclosed to measure a formation feature. An example apparatus includes a pre-processor to compare a first measurement obtained from a first sensor included in a logging tool at a first depth at a first time and a second measurement obtained from a second sensor included in the logging tool at the first depth at a second time. The example apparatus also include a semblance calculator to: calculate a correction factor based on a difference between the first measurement and the second measurement; and calculate a third measurement based on the correction factor and a fourth measurement obtained from the first sensor at a second depth at the second time. The example apparatus also includes a report generator to generate a report including the third measurement.

Abstract: A method of quantitative cement evaluation is provided. The method includes deploying a logging-while-drilling downhole sonic tool into a wellbore inside a casing, measuring acoustic signals propagating through the casing with the logging-while-drilling downhole sonic tool, and performing quantitative cement evaluation with respect to cement bonding around the casing by using waveform data of the acoustic signals measured with the logging-while-drilling downhole sonic tool.

Abstract: Systems and methods for determining a shear wave slowness may include emitting an emitted acoustic wave within a borehole from an acoustic tool. A return acoustic wave may be detected via one or more sensors. The return acoustic wave may be generated when the emitted acoustic wave interacts with a physical feature within the borehole. A signal may be generated that may be indicative of the return acoustic wave. The method may include evaluating the signal via a processor to determine a pseudo-Rayleigh mode slowness and calculating a shear wave slowness using an analytical relationship. The analytical relationship may include a mathematical correlation between the pseudo-Rayleigh mode slowness and the shear wave slowness. The analytical relationship may also include input parameters that are measured physical parameters of borehole properties.

Abstract: A downhole tool for operation within a wellbore and including a transmitter array and first and second receiver arrays. The transmitter array includes a plurality of transmitters azimuthally distributed around a longitudinal axis of the downhole tool at a first axial location of the downhole tool. The first receiver array includes a plurality of first receivers azimuthally distributed around the longitudinal axis at a second axial location axially offset from the first axial location. The second receiver array includes a plurality of second receivers azimuthally distributed around the longitudinal axis at a third axial location axially offset from the first and second axial locations.

Abstract: Apparatus and methods for identifying drilling cuttings downhole by extracting an echo from a pulse-echo waveform acquired utilizing a downhole ultrasonic tool having an acoustic device. An energy before echo profile preceding the extracted echo is determined, and then the energy before echo profile is processed to remove effects associated with the acoustic device. A cutting is then identified from the processed energy before echo profile.

Abstract: Provided are an internal olefin sulfonate composition which is capable of sufficiently enhancing foamability, foam dissipation property free from a slimy feeling during rinsing, and a feel after cleansing and subsequent drying, and a cleansing composition containing the same. The internal olefin sulfonate composition comprises (A) an internal olefin sulfonate having 16 carbon atoms and (B) an internal olefin sulfonate having 12 carbon atoms, in which a content mass ratio of the component (A) to the component (B), (A/B), is from 10/90 to 90/10.

Abstract: A downhole tool for real-time caliper measurements is provided. The downhole tool comprises multiple acoustic transducers mounted at different positions of the tool, and a control system. The control system drives the multiple transducers, receives pressure echo signals from the transducers, records the pressure echo signals in the memory, extracts data of two-way transit time and echo amplitude from the echo signals, and computes at least one of a borehole diameter, a tool center position, and an acoustic slowness or velocity of downhole fluid, based on the data of transit time and echo amplitude.