CRAM - Advanced Beam Migration
Improve reservoir imaging.
The 2D and 3D Common Reflection Angle Migration (CRAM™) is a cluster-based imaging system that generates conventional reflection angle gathers without azimuth dependency. Optimal local tapered beams are internally created and imaged to form high-quality image gathers, which can then be used in standard interpretation systems for accurate velocity model building and amplitude inversion (AVA).
CRAM IS AN INTEGRAL PART OF THESE ASPENTECH SUBSURFACE SCIENCE & ENGINEERING (SSE) SOLUTIONS:
- Preservation of subsurface angle-depend reflectivity amplitudes that can account for all possible arrivals (“multi-pathing”) and complex wave phenomena (caustics), and compensate for non-illuminated areas and angles
- Support for isotropic and anisotropic models (VTI and TTI)
- Customization for specific exploration or development targets
- Ability to run in preferred directions based on background directivities (dip and azimuth). This is especially important for accelerating the creation of reflection angle gathers and obtaining highly accurate gathers.
- Support for Q Compensation during the imaging process improves resolution, amplitude balancing and image quality by compensating for dissipation and attenuation effects resulting from gas hydrates or gas clouds. Q Compensation enables amplitude and phase preservation and higher-resolution imaging results.
UNIFORM ILLUMINATION OF THE SUBSURFACE
CRAM is ideal for imaging beneath salt structures, in overthrust areas, with wide angle or rich azimuth data, particularly where there is a dependence of velocity with azimuth (anisotropy).
In these environments, CRAM has been shown to improve:
- Imaging: As an anisotropic multi-arrival solution, CRAM uses the entire wavefield, making it ideal for solving complex imaging solutions.
- Amplitudes: CRAM performs imaging in the local angle domain to achieve uniform illumination from all angles and all azimuths. The resulting amplitude-preserved, angle-dependent reflectivity gathers are ideally suited for velocity model determination and amplitude analysis.
- Flexibility: You can customize CRAM to solve specific challenges, such as velocity determination and amplitude inversion. Or it can be run globally for an entire region.
With CRAM, geologists and geophysicists can:
- Perform tapered local slant stack (beams) and migrate only energetic events (beam steering).
- Create images with local slant stack events that provide significant multiple suppression for both surface and inter-bedding multiples.
- Enable QC of velocity model accuracy in selected locations from all angles.
- Enhance imaging and the creation of angle gathers, enabling the use of massive amounts of nodes.
- Generate data needed for tomographic velocity updates and amplitude analysis.