Online Journal for E&P Geoscientists

Polyakov, Valery ^*1; Omeragic, Dzevat ¹; Shetty, Sushil ¹; Brot, Benoit ¹; Habashy, Tarek ¹; Mahesh, Arathi ⁵; Friedel, Torsten ⁴; Vik, Torbjoern ²; Flugsrud, Tor Livar ³
(1) Mathematics and Modeling, Schlumberger-Doll Research, Cambridge, MA. (2) Schlumberger Information Solutions, Oslo, Norway. (3) Schlumberger Information Solutions, Stavanger, Norway. (4) Schlumberger Data and Consulting Services, Kuala Lumpur, Indonesia. (5) Schlumberger Data and Consulting Services, Abu Dhabi, United Arab Emirates.

We present an environment for high-angle and horizontal well evaluation integrated with reservoir geological models. It provides access to advanced 3D electromagnetic modeling algorithms for interpretation of resistivity measurements in complex 3D scenarios, going beyond the conventional layered-media models used for vertical and deviated wells. The environment is based on web services and includes high-performance computing (HPC) infrastructure enabling efficient running of modeling codes remotely, using all available computing resources (PC clusters, Grids or Clouds). The 3D well log modeling is embedded into a geomodeling package as a plug-in, thus enabling the interpretation of resistivity tool responses based on the underlying 3D reservoir model, by linking it to the parallelized simulators. The information inferred from the well logs is used in turn to fine-tune the 3D pillar grid-based reservoir model.

The system has been deployed in a giant carbonate field study to interpret hundreds of horizontal wells with varying extents and encompassing data from various wireline and LWD tools. The reservoir model was built using seismic and vertical well data. The results of log interpretation were propagated as a change to the pillar grid model. Examples demonstrate model refinement in a 2D cross-section by changing the dip and properties laterally to match the resistivity tool responses, and constructing a single model to match multiple log data acquired in three horizontal wellbores in close proximity.

The integrated workflow used in the process, from extraction of the reservoir model near the wellbore, to interactive model editing, such as structural updates or property adjustment, to the final stage of propagating changes made in a 2D “curtain” cross-section of the geomodel pillar grid back to the 3D reservoir model, yielded substantial efficiency gains. Saturation modeling on the scale of this case study had not been attempted before, and application of this new technology was the key to the successful execution of this study.

The new approach is essential for the interpretation of new-generation deep directional resistivity tools that are sensitive to the structure on the reservoir scale. It maximizes the value of log measurements by incorporating log information into the geomodels. Together with web services-based HPC simulation infrastructure, the system offers an unprecedented agility in formation evaluation and geomodel refinement process.