Meant to sdd this from Shell Oil page,
“On only a 30 x 40 foot testing area, Shell successfully recovered 1,700 barrels of high quality light oil plus associated gas from shallower, less-concentrated oil shale layers. Our research to date has demonstrated that our In situ Conversion Process (ICP) works technically on a small scale - what remains is to prove it can work commercially.”
Yes, a big 1700 barrels. And that’s from their most recent test in 2005. And their extraction process is enormously complex.