Schlumberger Technology Corporation

Vivian Pistre

Toshihiro Kinoshita

Hiroshi Hori

Chung Lung Chang

Tarek M Habashy

Bikash Kumar Sinha

Jahir A Pabon

Henri-Pierre Valero

Smaine Zeroug

Takeshi Endo

Hitoshi Sugiyama

Shu-Kong Chang

David Linton Johnson

Fernando Garcia-Osuna

Toru Ikegami

Alain Brie

Romain Prioul

Wataru Izuhara

Jakob Brandt Utne Haldorsen

GongRui Yan

Yoko Morikami

Yoshiyuki Saiki

Atsushi Saito

A technique facilitates determination of a quantitative bond between a pipe and adjacent materials, e.g. between a wellbore casing and adjacent cement. The quantitative bond is established via acoustic measurements related to signal attenuation. Additionally, the acoustic measurements may be conducted with a sonic tool during a wellbore operation, e.g. during a drilling operation. The methodology enables use of signal attenuation in a manner which facilitates determination of bond index coverage up to a high percentage, e.g. 100 percent.

Determining a quantitative bond using signal attenuation

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.

Method and system of quantitative cement evaluation using logging while drilling

A disclosed example method includes providing, in a borehole, a transmitter (Tx) and receivers (Rxs) spaced linearly from Tx at known distances, measuring linear propagation times (LPts) for a signal to propagate from Tx to each of Rxs, determining an inline velocity (V) based on LPts, measuring reflection times (Rts) for a signal to propagate from Tx to each of the Rxs via a boundary, for each of Rts, providing a time-distance anisotropic velocity (TDAV) relationship depending on an effective signal velocity (ESV) in an anisotropic formation adjacent the boundary as a function of reflection angle for the reflection time signal to the boundary, Vand orthogonal velocity, performing semblance processing to combine the TDAV relationships with Vfor a best-fit calculation of the ESVs for the different reflection angles of the reflection time signals, and calculating a distance for the corresponding receiver to the boundary on the calculation.

Methods and apparatus to calculate a distance from a borehole to a boundary of an anisotropic subterranean rock layer

Methods and systems for analyzing subterranean formations in-situ stress are disclosed. A method for extracting geological horizon on-demand from a 3D seismic data set, comprises receiving sonic log data; computing the anisotropic shear moduli C, Cand C; determining in-situ stress type and selecting an in-situ stress expression corresponding to the in-situ stress type; computing stress regime factor Q of the formation interval; and computing and outputting the maximum stress &#x3c3;by using the stress regime factor Q, Vertical stress &#x3c3;and Minimum horizontal stress &#x3c3;.

Method and system to determine the geo-stresses regime factor Q from borehole sonic measurement modeling

A method for in-situ calibrating acoustic receivers while the tool is in an open or cased borehole or during a logging run in a borehole. The method and system facilitate calibrating the acoustic receivers while they are mounted to a downhole acoustic tool. Calibrating the acoustic receivers in situ provides more accurate results than previously available. The method and system provide separate compensation factors for the acoustic receivers at different frequencies and for different transmission sources. The separate compensation factors facilitate more accurate signal acquisition over a wider range of conditions.

Methods and systems for calibrating acoustic receivers

An acoustic logging tool sleeve with a preferably discontinuous, alternating structure that is acoustically opaque in some zones, and acoustically transparent in others. The sleeve may be modular, with several stages connected together. The multiple stages provide a sleeve that may be useful with a variety of borehole logging tools to reduce or eliminate the transmission of noise to the receiving elements.

Acoustic logging tool sleeve

Methods for determining the best value for at least one slowness-related parameter that has been determined in a number of ways is disclosed. Sonic logging data input in the methods are processed to determine multiple values of at least one slowness-related parameter using slowness/time coherence (STC) processing methods. The error of each determined parameter is determined and the determined errors used in selecting a representative parameter value from the multiple determined slowness-related parameter values.

Processing sonic waveform measurements

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Tokyo, Japan

Vivian Pistre