Integration of Horizontal Well Log Data Into the Geological Interpretation: From Correlation to Mapping and Modeling

Thevoux-Chabuel, Hugues M.¹, Bruis Gianotten², S.K. Anand³, Karen Hoffman⁴ (1) Roxar Software Solutions, Oslo, Norway (2) Norsk Hydro, (3) Oil and Natural Gas Corporation Limited, (4) Roxar Software Solutions, Houston, TX

The integration of highly deviated and horizontal well information into the geological model is challenging in many aspects. Modern-day wells are steered within the same formation for hundreds of meters, undulating wells cross the same horizons multiple times and faults cause wells to enter zones without crossing their stratigraphic boundaries. For these environments a new approach is necessary to better correlate log information with previously drilled sections and to better constrain the mapping process to specific information defined along the trajectory.

First a “common multi-well stratigraphic reference” is introduced to visualize and interpret log information. Along a deviated well trajectory sections are generated, delimited by stratigraphic turning points and faults. The logs from each section can then be visualized in the stratigraphic domain and used in the correlation process.

The next step focuses on creating and adjusting correlation points along the horizontal well trajectory, which can be defined on faults, horizons, isochors and within formations. Multiple ways of constraining the mapping process based on the correlation points are demonstrated.

Thirdly an advanced log modeling method is presented, where measured log data can be compared with expected computed log values or, at a lower resolution, with the reservoir property model. Mismatch between modeled and measured logs can be a justification for revising the geological interpretation.

Finally the process is integrated into a workflow approach where the ultimate goal is to achieve “real-time” mapping and modeling updates.

Several field examples in different geological settings are used to illustrate the approach.