Z-Terra offers full service geophysical data processing, from time preprocessing to advanced depth imaging for a variety of geological environments with workflows individually customized to each dataset. Our workflows are designed to handle surveys of any size, from small 2-D projects to multiple merged large 3-D projects, and are designed to handle any acquisition type (land, transition, or marine) in challenging overthrust regimes (e.g., salt flanks, subsalt, fault shadows, and small fracture fields in thin unconventional shale plays) or in the presence of anhydrites, basalt, and volcanic rocks.
Trust in Our Geoscientific Expertise
Z-Terra’s experts have extensive 3-D time and depth imaging experience in a wide range of complex velocity and geologic regimes and regularly employ the following:
- Industry-standard refraction modeling to assure effective near surface control that is essential in removing shallow distortions allowing for correct subsurface depth imaging
- An integrated 3-D PSTM and PSDM velocity modeling toolbox and robust 3-D imaging algorithms in order to define an accurate 3-D migration velocity model
- A large proprietary toolbox of depth imaging solutions including Kirchhoff depth migration, Diffraction Imaging, Fast Beam Migration (FBM), wave-equation migration (WEM), and reverse-time migration (RTM)
- Proprietary software for integrated velocity model building employing various geology-specific migration velocity analysis update strategies (e.g., anisotropic wide-azimuth tomography) performed on Kirchhoff and FBM offset and angle gathers; WEM and RTM angle gathers: and Kirchhoff, FBM, WEM, and RTM extended gathers
- Integration of geologic and non-seismic data sources into velocity modeling
- Intensive QC processes and client collaboration at all stages
- Industry-leading technical expertise from beginning to end
- Flexible resources to meet the challenges created by technologically complex projects
Build Solid Project Foundations
Near surface travel-time distortion removal
- Accurate geometry information
- Consistent binning to a common grid
- Amplitude and phase matching
- 3-D consistent processes
- Consistent near-surface control
First break picking of each survey to a common datum with a common replacement velocity after each iteration allows for an area-consistent near-surface model to be developed as a foundation for surface-consistent 3-D reflection residual statics later in the processing flow.
Z-Terra will assure an accurate 3-D solution to mitigate long wavelength near-surface effects. Our approach removes both large and small scale near surface travel-time distortions providing confidence that the subsurface imaging can then be executed accurately.
Source generated direct and scattered ground-roll noise and/or air blast energy are expected to degrade existing data in the area. Z-Terra’s proprietary noise attenuation methodology effectively attack these noises in the most relevant data domains with the most appropriate attenuation techniques.
Shallow Data Continuity
The shallow levels of the 3-D datasets and the offset/fold relationships of the 3-D data can be addressed if there is limited consistent trace contributions at these levels. Z-Terra’s advanced 3-D trace interpolation methodologies may be used to provide greater consistency at these shallow levels to permit a best focused shallow 3-D image.
We perform seamless phase and amplitude matching of multiple adjacent surveys. In order to effectively merge the surveys, we select one survey as the “master” survey and focus on several key considerations: