Focus your seismic image, for a truer geological understanding of the subsurface.
Emerson's seismic tomography, part of the proven GeoDepth™ velocity modeling system, enables geophysicists to update the industry's largest velocity models - including velocity heterogeneity and anisotropy – efficiently and accurately. The unique set of input data provided by Emerson's seismic Imaging solutions (including full-azimuth image data), together with well information and a geologically constrained approach, delivers the most geologically plausible velocity model.
GeoDepth seismic tomography enhances seismic imaging results through:
- A fully automatic process that enhances efficiency and saves time
- A powerful combination of high-performance cluster computing, rich bottom-up specular ray tracing in all azimuths and angles, automatic reflection patch picking and residual moveout picking, and anisotropic model parameter updating. These are all applied to the client’s most critical seismic assets, where project turnaround and quality are paramount.
- Storage of all information, including picks and associated attributes (e.g. dip, azimuth and continuity of reflecting surfaces, surface ID, residual velocity, etc.) in the Pencil Database.
- Automatic picking of RMO at pre-defined pencil points along the prestack data: Offset and angle gathers, OVT (Offset Vector Tiles) sectored gathers, and EarthStudy 360 gathers
- A system for performing QC of residual moveouts generated from autopickers for all gather types, with selective and interactive exclusion of problematic residual moveouts based on quantitative criteria
- Full support for anisotropic velocity model determination, including vertical axis of symmetry (VTI) and tilted axis of symmetry (TTI), size and models. GeoDepth Tomography enables conversion of isotropic models to VTI/TTI anisotropic models and their update, ensuring the best positioning for reservoir targets
- Refraction tomography and refraction/reflection tomography for accurate and consistent shallow-to-deep velocity model buliding; highly performant on large datasets
- Calculation of update grids of depth varying resolution for surveys of any size, scaled according to data and model. Results in accurate velocity models, especially in shallow areas, and reduced project cycle times.
- Multiple inversions to solve the tomography matrix, with different geological constraints applied independently to each geological layer or model creation of complex geology.
- Optimal operation on large computing clusters with many nodes, enabling computations involving hundreds of gigabytes for typical grid intervals of several hundred meters.
- Distributed computations over the two main tasks of tomographic matrix creation and solution.
- Integration of well information (check shots) into tomography equations for solving and controlling anisotropic inverted parameters.
- A full tomographic velocity model update workflow using OVT sectored gathers as input
- Multiple Parameter mode: Enables users to simultaneously run multiple tomography jobs using different parameter setups, and assess and compare results with easy visualization and using pre-defined statistical measures. Also helps assess model uncertainty.
- Built-in protection against hardware failure (fault tolerance), so no time lost
WHY SETTLE FOR ONE-SIZE-FITS-ALL TOMOGRAPHY?
Not all subsurface environments are the same. GeoDepth seismic tomography supports 3D grid refraction and reflection, model-based reflection, and hybrid tomographic methodologies, customized to the problem at hand. In 3D model-based tomography, velocity parameters are represented along the depth model horizons. The velocity parameters and the depth structure are updated along the background structural model. Unlike grid-based tomography, in which only the velocity parameters are updated on a predefined coarse 3D grid, model-based tomography updates both the velocity field along the geological layers and the location of subsurface horizons.
OPTIMIZE VELOCITY MODEL DETERMINATION
Advanced tomography workflows need a massive amount of support from the most powerful geoscience systems. Each stage in the process must be analyzed and optimized in order to enable fast and reliable QC that will ensure effective convergence to the most accurate solution. The Emerson E&P software suite provides technologically advanced components that bring the different types of tomography workflows to a successful outcome:
- A novel 3D geomodeling solution (SKUA™) to build and update geologically plausible subsurface structure models
- A comprehensive anisotropic ray tracing system (EarthStudy 360™ Illuminator)
- Efficient and accurate prestack depth migrations for generating the subsurface image and the offset/angle domain CIGs (Kirchhoff and RTM migrations, CRAM /EarthStudy 360 Imager)
- A powerful visualization and interpretation system (SeisEarth™ 3D Canvas) for automatic event picking in both poststack and prestack domains