A technical webinar was organized by SPG, India on “Horizons and Well Tops - Where Data meets Reality” on 22nd March 2022 by Suresh Nistala, Ecopetrol, Bogota. The technical webinar highlighted through reviews on legacy onshore seismic data andits challenges of accurate velocity models.Mr. Nistala discussed about several modern processing techniques (i.e., de-ghosting, Q compensation and Q migration etc.)and how these techniques can be used to get a correct velocity model.He also emphasised on the uses of geologically constraint attributes such as well markers, check shots etc. for reprocessing of the seismic data and these are the key to getting the Velocity Models correct. Mr. Nistala had shown example of first 3D seismic survey in Colombia.He described about the using of check shots and well logs to get a correct velocity model which resulted in desired PSDM imaging and lowering of risk.

The horizon-based velocity analysis creates geometrically consistent velocity models tied in 3D, reducing the positioning uncertainty of steep horizons, and imaging the geological structures with greater accuracy and detail.

The geometry and position of the events is refined in time as well as in depth. The final velocity field for PSTM is stable as an input to tomographic update iterations for PSDM. Vertical or horizontal smoothing is in principle not applied at any stage, but if required, small smoothing operators can mitigate for minor artefacts in the velocity field.

The webinar session was attended by the members of SPG-India from all over the country and geoscientists of KDMIPE, GEOPIC, Frontier Basins and professors and students from different Institutes. The lecture was well appreciated by all the participants and praised by one and all for its contents and thoughtful discussion provided by the presenter. During the webinar session participants actively participated on discussion and asked various question related to velocity model building and uses of horizon tops and check shot data for seismic imaging.

Earlier, Shri Shiv Kumar Sharma, President, SPG-India gave the welcome speech. The vote of thanks was given by Secretary SPG-India Shri Onkar Singh. The entire webinar session was coordinated by Dr. Subhash Kumar Sharma, Treasurer, SPG-India.