I have to disagree strongly. The seismic data is probably at least as valuable as the well data. There is a reason that the acquisition contractors and other data owners don't make regular releases of old, legacy data for the public domain.

It really has an infinite shelf life due to the processor's ability to periodically employ newer, faster algorithms on newer, faster hardware to produce products that, though they frequently show only marginal differences, are still marketable as new products or upgrades over old datasets.

Legacy data, due to the acquisition methods employed decades ago, cannot be replicated today. You will not get a permit to acquire airgun data today using the same energies they routinely used a few decades ago nor will you be able to use a broadband source like dynamite offshore. It was routine back in the 60's and 70's. The bandwidth of data today is different. New source types and improvements to old sources can help but the old data has tremendous value as a calibration. The penetration of energy for imaging the deepest events in the subsurface is so much better in old data due to the low frequency penetration characteristics of old sources (higher energy sources).

If you look around for free or publicly available seismic data there really isn't much and ten years ago there was almost none that was easy to find. Industry groups hoping to help newcomers learn by processing raw field data have always been beggars to the data holders. Licensing restrictions follow data everywhere and a lot of it comes with tight constraints on how it can be used and whether it can be published.

Most contractors hold tightly to their data because it doesn't matter how old it is, you can always squeeze it through another processing flow and output a brand new, improved product and offer that for sale to your existing and prospective clients. Old surveys get new names, they are merged with new data using match filters and cross-correlations and tied so that it is not possible to tell where the old data coverage ended and the new data began.

I started processing almost 30 years ago. Some of the data we processed then was already 20 years old. It served to help a client decide whether a new survey would offer any value to their exploration efforts by contributing a more detailed subsurface image. 2D was a great reconnaissance tool and still is today. By reprocessing some 2D data a client can focus their 3D efforts on proscpects where the potential for success are highest thus cutting their costs and if you think cost cutting isn't a thing in the oil patch, seismic data processing is a loss leader for the big contractors.

I did some 4D seismic processing which involves acquisition of new data using the exact same parameters and processing flows as were used in the first survey. New data is then compared to older data so that operators can see the tell-tale changes in their reservoirs which indicate migration of fluids in the subsurface during production or fluid invasion during waterfloods or CO2 floods.

Old data never dies nor does it lose its value. Like I mentioned above, new data gets matched to old, old data gets matched to new. Any time a survey is acquired for the first time in an unexplored area, that survey data becomes the ground truth dataset. All future data will be compared to it for quality, bandwitdh, signal to noise ratio, etc.

Geophysics, or seismic data processing, really is a "what do you want it to look like" operation. Once you know the acquisition geometry then you can determine everything you need to know to image the subsurface just by smashing it through enough algorithms to filter out all the geology-related attributes like formation velocities, amplitudes - especially anomalous amplitudes, formation thicknesses and their depths below the surface or the seafloor, fluid content, etc. It really is amazing what you can discover without once touching a rock today. It goes so far beyond imaging subsurface structures. I love this field of work.

I am pretty happy to see seismic data released for personal use. I will be digging through this to see what I can find.