Schlumberger Technology Corporation

Services Petroliers Schlumberger

Geoquest Systems B.v.

Ting Lei

Bikash Kumar Sinha

Smaine Zeroug

Sandip Bose

Jiaqi Yang

Tarek M Habashy

Pu Wang

Ma Luo

Lin Liang

Ram Sunder Kalyanaraman

Romain Prioul

The subject disclosure relates to the interpretation of borehole sonic data using machine learning. In one example of a method in accordance with aspects of the instant disclosure, borehole sonic data is received, and machine learning is used to interpret the borehole sonic data.

Machine learning enhanced borehole sonic data interpretation

A method, computer program product, and computing system for generating high resolution slowness logs. The method computer program product, and computing system includes receiving a plurality of sonic logs from at least one sensor array and generating at least one high-resolution slowness log from the plurality of sonic logs based upon, at least in part, monopole and dipole data from the plurality of sonic logs.

System and method for generating slowness logs in thinly laminated formations

Aspects of the disclosure provide for a method using clusters of sonic peaks from a logging tool to generate a log of an acoustic property of the formation as a function of depth.

Multi-resolution based method for automated acoustic log depth tracking

A method is presented wherein inversion for formation anisotropic constants is achieved using borehole sonic data.

Data driven method to invert for the formation anisotropic constants using borehole sonic data

Methods are provided for determining properties of an anisotropic formation (including both fast and slow formations) surrounding a borehole. A logging-while-drilling tool is provided that is moveable through the borehole. The logging-while drilling tool has at least one dipole acoustic source spaced from an array of receivers. During movement of the logging-while-drilling tool, the at least one dipole acoustic source is operated to excite a time-varying pressure field in the anisotropic formation surrounding the borehole. The array of receivers is used to measure waveforms arising from the time-varying pressure field in the anisotropic formation surrounding the borehole. The waveforms are processed to determine a parameter value that represents shear directionality of the anisotropic formation surrounding the borehole.

Methods and systems for determining fast and slow shear directions in an anisotropic formation using a logging while drilling tool

Methods and systems are provided that identify relatively large anisotropic horizontal stresses in a formation based on (i) azimuthal variations in the compressional and shear slownesses or velocities of the formation measured from ultrasonic data acquired by at least one acoustic logging tool as well as (ii) cross-dipole dispersions of the formation measured from sonic data acquired by the at least one acoustic logging tool. In addition, the azimuthal variations in the compressional and shear slownesses or velocities of the formation and dipole flexural dispersions of the formation can be jointly inverted to obtain the elastic properties of the rock of the formation in terms of linear and nonlinear constants and the magnitude of maximum horizontal stress of the formation. A workflow for estimating the magnitude of the maximum horizontal stress can employ estimates of certain formation properties, such as overburden stress, magnitude of minimum horizontal stress, and pore pressure.

Estimation of horizontal stresses and nonlinear constants in anisotropic formations such as interbedded carbonate layers in organic-shale reservoirs

Methods and systems are provided for determining cement quality in an outer annulus of a multi-string cased wellbore having an inner annulus of mud. Data from a sonic logging tool is processed to obtain a slowness dispersion. The slowness dispersion is compared to a plurality of model slowness dispersions generated for a plurality of different values for cement quality in the outer annulus. The cement quality in the outer annulus is determined based on the comparison.

Method for analyzing cement quality in multi-string cased wells using sonic logging

Methods are provided for identifying a cementation status of a multi-string cased wellbore utilizing sonic tools with monopole and/or dipole transmitters and with an array of sonic receivers axially displaced from the transmitter(s). The sonic tool is used to record waveforms. The waveforms are then processed to generate slowness and/or attenuation dispersions. The slowness and/or attenuation dispersions are projected onto a slowness and/or attenuation axis, and the results are compared to a data set of projected slowness and/or attenuation dispersions representing a plurality of different multi-string cased wellbore cement status scenarios in order to select the scenario most closely associated with the results. The presence or lack of eccentering of a casing is similarly obtained where the data set includes projected dispersions representing properly centered and ec-centered casings.

Method for analyzing cement integrity in cased wells using sonic logging

Methods are disclosed for detecting fluid in at least one annulus around at least one casing installed in a borehole traversing a formation utilizing a sonic tool. The sonic tool is activated in the borehole and the received sonic waveforms are processed to obtain a dispersion plot. A reference dispersion plot is generated using a model of the borehole where the casing is well-bonded by cement. The obtained and reference dispersion plots are compared. An indication of fluid and in some cases, the specific radial location thereof is obtained based on the signature of the obtained plot as opposed to the reference plot. The methods are effective in doubly-cased boreholes using monopole and/or dipole sources.

Sonic logging for assessing well integrity

A method for torsional wave logging in a borehole of a subterranean formation. The method includes obtaining a torsional wave measurement of the borehole, wherein the torsional wave measurement represents characteristics of a torsional wave propagating within a cylindrical layered structure associated with the borehole, wherein the cylindrical layered structure comprises the subterranean formation and a completion of the borehole, analyzing, by a computer processor, the torsional wave measurement to generate a quality measure of the completion, and displaying the quality measure of the completion.

Torsional wave logging

Apparatus and method for characterizing a barrier installed in a borehole traversing a formation including locating an acoustic tool with a receiver and a transmitter at a location in the borehole, activating the acoustic tool to form acoustic waveforms, wherein the receiver records the acoustic waveforms, and processing the waveforms to identify barrier parameters as a function of azimuth and depth along the borehole, wherein the waveforms comprise at least two of sonic signals, ultrasonic pulse-echo signals, and ultrasonic pitch-catch signals.

Acoustic multi-modality inversion for cement integrity analysis

A technique facilitates determination of fracture attributes through the recording and analyzing of borehole sonic data before and after a fracturing operation. The technique comprises generating broadband acoustic waves at an array of receivers based on output from a plurality of acoustic sources. The waveforms of the broadband acoustic waves are recorded and processed to estimate sonic signatures. The sonic signatures are then used to determine fracture attributes. In some applications, the data may be used to determine whether the fractures in the formation are filled with fluid or soft sediments. Information on the fracture attributes is output to a suitable system, e.g. a computer display.

System and methodology for determining fracture attributes in a formation

Systems and methods for identifying sanding in production wells using time-lapse sonic data. Formation anisotropy can be characterized in terms of shear moduli in a vertical wellbore, e.g., vertical shear moduli Cand Cin the wellbore axial planes and horizontal shear modulus Cin the wellbore cross-sectional plane. Changes in formation anisotropy between different times can provide qualitative indicators of the occurrence of sanding in the production well. Before production begins, the horizontal shear modulus Cis typically less than the vertical shear modulus Cor Cor both. At a subsequent time after sanding occurs, the horizontal shear modulus Cis typically greater than the vertical shear modulus Cor Cor both. By comparing the shear moduli of the vertical wellbore at different times, it is possible to identify the occurrence of sanding in the production well using time-lapse sonic data.

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Cambridge, MA, United States of America

Ting Lei