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addition, the regular improvement in imaging technologies implies interpretation can be signifcantly affected in some cases. As a result, interpretation in challenging geological regimes evolves over time as more and more uncertainty in the image is resolved with ever better imaging tools.

SLB: The interpretation and the processing of the image (seis- mic) is an iterative process. To get the best image, interpretation needs to be done to apply depth-imaging algorithms and get a clearer image, then a new interpretation is done and another depth imaging step is run, and this goes on until we get the best quality possible. The interpretation is done in the Petrel platform relatively quickly, depending on the size of the area to interpret, then it is seamlessly sent to Omega geophysics data processing

Example of PrimaViz 3D visualization. Image from TGS.

software to get the new depth image even sharper and more accu- rate. When the data is acquired offshore, a frst pass processing is

OE Is the interpretation done in real-time with the client done on the boat, which provides the frst image. Then the itera- : involved?

tive loop starts. This can take a few weeks or months, depending

PGS on the complexity of the subsurface. But today, because the tight : Interpretation of the fnal image is almost exclusively link between the interpretation and visualization undertaken in done by the client. The exception is during the velocity model the Petrel platform and the Omega processing software, this time building stage where interpretation required to control model is hugely reduced. compartments can be conducted in real time. It is typical

TGS : Once the very frst depth images are available, the for a client to send interpretation and imaging specialists to interpretation begins and becomes an iterative process until PGS’ offces for up to one week, during which time the cli- the imaging objectives are achieved. The length of the pro- ent knowledge is integrated into the model building process. cess depends on the size of the processing area, density of the Interpretation updates can be then migrated in real-time and the acquired data, and complexity of the area from an imaging and impact upon imaging assessed.

TGS interpretation sense. Large regional multi-client 3D surveys can :The client is normally always involved in the interpreta- take up to one year or more to process and interpret from start tion, as they have the best insight into the geologic details of the to fnish, while smaller prospect level reprocessing projects area. The picking can be done in real-time either by the inter- could take roughly half of that time. pretation group at TGS (with client input) or by the client.

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