Schlumberger Technology Corporation

Denis Syresin

Takeshi Endo

Naoki Sakiyama

Takashi Katagiri

Hiroaki Yamamoto

Henri-Pierre Valero

Atsushi Oshima

Hiroshi Akima

A system may obtain orthogonal pairs of acoustic waveforms obtained by a rotating downhole acoustic tool. The downhole tool may include an acoustic transmitter and an acoustic receiver. A computing device communicatively coupled to the downhole tool that instructs the transmitter to generate the various waveforms detected by the acoustic receiver and store the various waveforms in a buffer. Each waveform of a subset of the various waveforms oriented in a similar direction may be stacked to generate a composite waveform with reduced noise. The computing system may determine an orthogonal pair of waveforms based on the composite waveform and remaining waveforms.

Systems and methods for acquiring orthogonal pairs of waveforms for acoustic well logging

Methods, apparatus, and articles of manufacture are disclosed to characterize acoustic dispersions in a borehole. An example apparatus includes a dispersion analyzer to characterize an acoustic wave dispersion in a borehole in a formation by calculating a quality indicator corresponding to the acoustic wave dispersion, and a report generator to prepare a report including a recommendation to perform an operation on the borehole based on the quality indicator.

Methods and apparatus to characterize acoustic dispersions in a borehole

A method for processing sonic data measured with a downhole tool is provided. The method comprises acquiring dipole wave data measured by a dipole acquisition in multiple firing, and estimating at least one of formation anisotropy properties based on the multiple firing dipole data. The at least one of formation anisotropy properties may be derived by Alford rotation processing. The method may further comprise processing with inversion of an orthogonality error angle of the firing data in two dipole firings and/or providing a quality control with the estimating result based on sonic measurements in a pump-off period.

Method and system for processing dipole anisotropy

A technique facilitates estimating elastic properties of formations by exciting a wavefield and acquiring the signal with and without azimuthal decompositions. For example, the elastic properties may be estimated by exciting a multipole wavefield and acquiring the signal with and without the azimuthal decomposition. The technique is effective for estimating elastic properties of azimuthally homogeneous and heterogeneous formations including isotropic and anisotropic formations.

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Kanagawa-ken, Japan

Denis Syresin