To set up a petroleum exploartion and production industry takes more than just a few yrs.
I heard the japanals did inspect the area around daqing but little to to their satisfaction.
Finding a few sea shells in rocks doesn't equate knowing the geology and history.
Let me see, the modern way of seismic data handling is digitalising the signal, feed them thro various correction, filtering , stacking , migration and what nots programs.. Basically fourier analysis, inversion and solving differential eqts done thro a computer.
Back in the 30s, even if they had the equipment to get crude analog signal, all the processing could only be done manually(they didn't have analog computers) and crudely. Good luck.
By the way, oil was discovered in US and saudi arabia because the deposits were shallow and it just gushed out.