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    3d Far Field Middle East Cs

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    lakhanmukhtiar
    3d-far-field

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    3d Far Field Middle East Cs

    Uploaded by

    lakhanmukhtiar
    90 views2 pages
    3d-far-field

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    3d-far-field-middle-east-cs

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    3d-far-field

    Copyright:

    © All Rights Reserved
    Download as PDF, TXT or read online from Scribd
    Download as pdf or txt
    90 views2 pages

    3d Far Field Middle East Cs

    Uploaded by

    lakhanmukhtiar
    3d-far-field

    Copyright:

    © All Rights Reserved
    Download as PDF, TXT or read online from Scribd
    Download as pdf or txt
    of 2

    CASE STUDY

    3D Far-Field Sonic and Borehole Imaging Confirm


    Fault in Lieu of Seismic Data
    Automated workflow for structural dip and azimuth in complex carbonate reservoir
    resolves modeling uncertainties, Middle East
    CHALLENGE Structural uncertainty without surface seismic data
    Resolve structural uncertainties resulting from Surface seismic surveys had not been conducted in a Middle East field because of surface constraints.
    the lack of a surface seismic survey to define This lack of data created uncertainties in the structural setting for defining the appraisal target
    the appraisal target in a carbonate reservoir. in the carbonate reservoir.
    SOLUTION Automated time picking, ray tracing, and 3D STC
    ■ Perform 3D far-field sonic service on FMI microimager logs in the main well and sidetrack showed the depth and orientation of a possible
    waveforms acquired by the Sonic Scanner* fault cutting across both wells. To pinpoint the position of the fault away from the wells and deep
    acoustic scanning platform by applying into the reservoir, Schlumberger proposed conducting 3D far-field sonic service. The service applies
    automated event identification and a patented end-to-end workflow to data obtained with eight azimuthal sensors at 13 receiver stations
    analysis to map and characterize the of the Sonic Scanner platform.
    corresponding reflectors.
    The 3D far-field sonic service automates time picking to rapidly and consistently analyze thousands
    ■ Integrate the 3D sonic imaging results
    of shot gathers to identify reflection events. Ray tracing inversion of the time picks and 3D slowness-
    with wellbore images from the FMI*
    time-coherence (STC) analysis of the underlying arrival event determine each event’s type and
    fullbore formation microimager to confirm
    position to efficiently guide the smart migration workflow. The resulting 3D sonic image produced
    fault delineation.
    in the Techlog* wellbore software platform is consistent with the event type and orientation of the
    RESULTS true reflections, with their direct association providing strong quality control.
    Confirmed the presence of the possible fault
    through abrupt changes in reflector dip and
    a drag effect, in alignment with the wellbore
    images, to resolve uncertainty in updating the
    structural model.

    The 3D STC reflector discs imaging the dip and azimuth are shown with the migrated monopole image along the wellbore.

    Formation Evaluation
    CASE STUDY: 3D far-field sonic service confirms fault in lieu of seismic data, Middle East

    3D Far-Field Sonic Service FMI Microimager


    N N
    W E W E
    S S
    Classification Classification
    Bed Boundary Fault, open
    Fracture Fracture, open
    General bedding
    Possible fault
    Depth, Gamma Ray True dip True dip
    ft 0 gAPI 150 0 ° 90 0 ° 90

    X,X50

    X,X75

    X,X00

    X,X25

    Dip and azimuth from 3D sonic imaging in Track 3 confirm far-field structural changes interpreted in Track 2 from
    the FMI microimager above and below the fault identified at about X,X85–X,X95 ft.

    Fault projection from the wells across the reservoir


    The results of 3D far-field sonic service and the near-wellbore image logs were integrated to trace
    the possible fault across the reservoir. One of the projected surfaces from the main well matched
    the expected depth of the formation top in the sidetrack but two were offset due to the possible
    presence of the fault.

    The fault’s presence was confirmed by parallel evaluation of the azimuthal sonic-imaging data
    acquired in the main well that showed an abrupt change in the relative dip of reflectors above
    and below the possible fault plane using the service’s 3D STC analysis and ray tracing. Dip
    patterns from both wells also showed a drag effect around the offset formation tops, providing
    further confirmation.

    With the fault’s position determined, the uncertainty in the structural model could be resolved
    in the Petrel* E&P software platform.

    For additional details, see N. Bennett et al., “Borehole Acoustic Imaging Using 3D STC
    and Ray Tracing to Determine Far-Field Reflector Dip and Azimuth,” Petrophysics 60, no. 2
    (April 2019), 335–347.

    slb.com/3DSonic

    *Mark of Schlumberger
    Other company, product, and service names are the properties of their
    respective owners.
    Copyright © 2020 Schlumberger. All rights reserved. 20-FE-5840384

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