INTEGRATION OF WELL LOGS AND RESERVOIR GEOMODELS FOR FORMATION EVALUATION IN HIGH-ANGLE AND HORIZONTAL WELLS

摘要

We present a high-performance computing (HPC) environment for high-angle (HA) and horizontal (HZ) well evaluation integrated with reservoir geological models. The new environment allows access to advanced 3D electromagnetic (EM) modeling algorithms and workflows for the interpretation of resistivity measurements in these wells and in complex 3D scenarios, going beyond the standard layered-media models used for conventional interpretation in vertical and deviated wells. This approach is especially important for the new generation of deep directional resistivity tools, providing sensitivities to structure on the scale of the reservoir. The 3D well log modeling is embedded as a plug-in geological modeling package. This workflow implementation enables modeling of resistivity tool responses based on the underlying reservoir geomodels by linking these to simulators parallelized to run on PC clusters and grid. The information contained in well logs is then used to finetune the 3D reservoir models. The results of log modeling are propagated as a change to the pillar grid model, which is subsequently accommodated in an automated manner in the geomodeling package. A fully functional research prototype was recently deployed in a giant carbonate field study for interpretation of large number of horizontal wells of varying lengths logged with several wireline and LWD tools. The reservoir model was built using seismic and vertical well data and refined using modeling-based interpretation of hundreds of horizontal well logs. We present the 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. Efficiency gains from utilizing this new modeling environment are tremendous, which makes it the modeling package of choice for petrophysical interpretation.