Even air resistance would become a more complex problem with depth.
For Shell, a million dollars indicates interest, but that is small money in the big picture. It may well work in areas where producing formations are shallow (3000 ft. or less) and large numbers of vertical holes are desirable versus horizontal drilling.
From what I’ve read, it looks like this is a plan for geothermal wells, not oil/gas production.
And Shell’s GameChanger program seems to be a 1 in 10 success ratio. Seems more like marketing and charity work.