Valery Polyakov

Workflow to Automatically Update Geological Models during Well Placement with High Angle and Horizontal Well Log Interpretation Results

We present a novel methodology for integration of high-angle/horizontal (HA/HZ) well data into 3D geomodels as a natural extension to well placement workflows. Log interpretation, typically done in 2D cross-sections, is based on 1-D automated inversion, yielding near-wellbore reservoir structure and properties. 2D cross-section, updated by inversion and further refined using 2D/3D modeling, is subsequently retrofitted into the geomodel so as to minimally perturb the original topology. Changes in positions/dips/azimuths of boundaries and faults, cell properties, and further local grid refinements are applied automatically. The updated geomodel honors high-resolution logs and low-resolution seismic/nearby wells data. We demonstrate this on a typical real-time well placement scenario. Electromagnetic log interpretation codes are integrated as a high performance computing (HPC) Web service into a geosteering/model update workflow. As the initial model, we use 3D geomodel constructed from seismic/vertical well data. A ―curtain‖ cross-section is extracted, edited based on 1D inversion, and further refined to match HA/HZ logs through 2D and 3D forward modeling, by changing properties/dips/layer thicknesses /fault positions, while preserving the original topology. Then, updated node coordinates and cell properties of the affected pillar grid region are calculated to optimally retrofit the changed 2D cross-section into the grid. These changes are then automatically applied to the 3D model. For quality control, we recompute the 2D cross-section from the refined geomodel. Ultimately, we arrive at the geomodel that honors both seismic and resistivity well-log data. The combination, in a single workflow, of physics-based log modeling codes, Services-Oriented Architecture, HPC framework, and the solver to optimally retrofit 2D cross-sections into 3D models, creates a qualitatively new opportunity for well placement engineers. This integrated workflow (1) maximizes the value of deep directional resistivity well-logs and real-time well placement interpretation by incorporating them into the source of data for building geomodels; (2) radically speeds up the model refinement loop by automatically calculating and applying the modifications to 3D reservoir model; (3) enables geoscientists to directly refine geomodels while geosteering. The latter has not been a standard practice, hindered by challenges of scale difference between geomodels and well-logs and lack of availability of efficient modeling codes.

Simulating Sonic Scanner responses in an interactive Web‐based High Performance Computing environment

Sonic Scanner logging tool collects a wealth of data about the geological formation. The drawback of this is that we are now discovering new features on the acoustic logs that have never been observed before; only rigorous modeling can help properly interpret the data. Invariably, it is difficult to learn quickly how to run a modeling code, set the parameters properly, and be able to detect possible errors in the input. In addition, complex modeling requires high power computing resources, which are not always easily accessible the user. To address these problems we developed a multi‐tier Web‐based log modeling environment where the Sonic Scanner simulator is easily accessible from the common Web browser. The user builds the model in an intuitive AJAX‐like interface and submits the simulation to a remote High Performance Cluster. The computed waveforms are played back in the browser using Scalable Vector Graphics in a variety of customizable displays. The Web application is easily available to any user with an Internet access. In addition, a programmatically accessible Web service is available to application developers who desire to build their own interpretation applications using the Sonic Scanner simulator engine.