3D Far-Field Sonic Service, Lateral Logging | Schlumberger-巴黎人会员登录
Case Study
Details

An operator of a field detected the extent of naturally fractured intervals using azimuthal sensors from a 3D far-field sonic service—providing a deeper depth of investigation into the reservoir than resistivity borehole imaging techniques.

Products Used

3D Far-Field Sonic Service Identifies Fracture Intervals Undetected by Borehole Imaging

Automated sonic imaging workflow complements traditional resistivity borehole images to increase depth of investigation into the reservoir

Identify fracture intervals undetectable from borehole seismic data alone

An operator needed to determine porosity from sonic slowness and use wellbore images along with surface seismic interpretation to identify structural features. Identification of fracture intervals is normally done with borehole imaging data alone; however, the operator needed a solution that would provide a deeper depth of investigation into the reservoir and determine the extent of the fractured zones.

Use far-field imaging to obtain more comprehensive data along the lateral

Both standard and slim dipole sonic logging tools were deployed to obtain images along the lateral. The slim dipole sonic image, acquired on through-the-bit logging conveyance, was similar to the image obtained from the standard sonic tool, and both images captured the major boundaries along the well track.

Schlumberger then provided the 3D farfield sonic service to identify fractures tens of feet away from the borehole region. Complementing traditional sonic imaging techniques and borehole imaging logging, the automated 3D far-field sonic service rapidly provides the true dip and azimuth of fractures and formation layers located well beyond the reach of standard sonic logging. The service determines connectivity for open fractures and identifies subseismic structural features, tracing them from the borehole wall through the near-field and far-field reservoir. Using the 3D far-field sonic service, data was recorded along a high-angle interval with a borehole diameter of 57/8 in and well deviation ranging between 84° and 90°. 

Rose plots showing image log conductive fractures and faults, standard sonic data, and slim sonic data.
Rose plots showing image log conductive fractures and faults, standard sonic monopole and dipole data, and the slim monopole and dipole sonic data. The azimuth obtained from sonic data showed good agreement with image log results.
Fractures from image log data in comparison with fractures from 3D far-field data.
Fractures from image log data (pink discs) in comparison with fractures from 3D far-field data using the standard dipole sonic measurements (blue planes) and slim dipole sonic measurements (orange planes), detecting fractures up to 60 ft away from the borehole.

Map a deeper depth of investigation

Using azimuthal sensors from the complementary 3D far-field sonic service detected the presence of naturally fractured intervals. The orientation (dip and azimuth) of these features was consistent with the borehole image and provided a deeper depth of investigation into the reservoir, seeing fractures of up to 60 ft away from the borehole.

overflow image
Image log results comparison with 3D far-field sonic data. From left to right: borehole image log results, monopole far-field results of standard sonic tool, dipole data results of standard sonic tool, monopole far-field results of the slim sonic tool, and dipole results of the slim sonic tool.
Products Used

Share This