OUR SERVICES

The core of our services is the successful execution of every depth imaging projects. Our services include  the three technologies required for successful execution of every depth imaging project: model building, prestack depth migration and data analysis.

The quality of the final depth migrated volume is as good as the velocity model constructed during the model building phase. We devote the majority of the depth imaging process to building an accurate velocity model. Our workflow is based on repeat iterations of full volume prestack depth migration where at each iteration the model is updated using the results from the prior depth migrated image. Every model building iteration is performed using full volume prestack depth migration.

We are using GoCad technology for structural modeling. This involves detailed interpretation of major layer boundaries (such as salt bodies), construction of model surfaces, combination of surfaces to form geological bodies, and then application of topology to assign velocity functions to the different compartments of the model.

Velocity analysis is done using two tools: reflection tomography and prestack depth migration scans. We are using the scan technique to obtain the initial velocity model, followed by reflection tomography to add details to the velocity model. Combination of the two tools enables us to develop accurate velocity models to be used in prestack depth migration.

Our model building tools are suitable for construction of GOM type models with smooth sedimentary velocity function and detailed salt bodies, as well as layer based models needed for imaging overthrust geology.

We offer a series of prestack depth migration algorithms, ray trace and wave equation based. These include a wavefront reconstruction Kirchhoff summation algorithm, common shot downward extrapolation wave equation algorithm, and common shot two-way wave equation (i.e. RTM) algorithm.

The appropriate algorithm is selected based on the geological setting and the imaging objective. In most cases we use repeat iterations of full volume Kirchhoff summation algorithm for the major part of model building, one-way wave equation for model validation, and conclude with two final runs, using one-way wave equation and Kirchhoff summation algorithms. We are using the two way wave equation algorithm (RTM) for cases that we can improve the image using both ‘down going’ and ‘up going’ waves.

Our prestack depth migration algorithms are implemented in the common shot domain. No data decimation or conditioning is applied prior to prestack depth migration. All prestack depth migrations are full volumes with image gathers output at each migrated bin.

Anisotropic model building and prestack depth migration

We are now offering full anisotropic model building and prestack depth migration. This is done as part of our Kirchhoff summation work-flow. The objective of the anisotropic model building and imaging is to construct a depth migrated image that will better match observed well data. The anisotropic depth migrated volume will image events in different depth as well as horizontal position, compared to isotropic depth migrated volume producing a more accurate result.

We are building and supplying a 3-parameter model as input to our anisotropic prestack depth migration. The three parameters are vertical velocity volume, delta volume and epsilon volume. Our model building velocity analysis tools were modified to scan and optimize each one of these three parameter fields.

Our anisotropic depth imaging workflow is routinely used to produce a more reliably positioned as well as better imaged volume.

In most cases, seismic data include coherent noise which makes the interpretation of depth migrated data more challenging. As part of our services, we offer several wave equation simulation workflows that are capable of generating noise patterns, and by that aid in the interpretation of seismic data. We call this process image analysis.

Surface related multiples, inner-bed multiples, diffracted multiples, migration ‘swings’, or prism waves are examples of coherent noise patterns that can be part of the migrated image. Using our two-way full wave equation simulation tool we are capable of generating any of these noise patterns and by comparing to the real data, better understand the depth migrated images.

Data simulation projects are executed for one of the following objectives:

• Post imaging, as part of analysis of the real data
• As part of model building, as an aid to interpretation
• To investigate amplitude variations in areas of low illumination 

Modern marine acquisition design can be optimized by use of 3D wave equation simulation. With our 3D two-way wave equation simulation algorithms, we are offering simulation based acquisition design. This service includes generation of a detailed 3D model, simulation and recording of a dataset over a large grid, and then imaging using subsets of the recorded dataset. With this workflow, key acquisition parameters can be optimized such as cable length, azimuth distribution, number of gun and cable boats as well as the optimal sailing directions.