We have made the first steps in validating the application of the NMR spin-lock T1ρ sequence for the determination of the calibrated viscosities of oils in geological porous rocks. As an initial stage, we have measured the T1ρ relaxation times for four oils from Brookfield Engineering, of given calibrated viscosity. That work will be published in detail elsewhere. Here we are applying these calibrated measurements to measure the T1ρ values of the same oils in a porous sandstone rock. We have measured the T1ρ spin-lock relaxation time for one Brookfield Engineering calibrated viscosity oil, both in the bulk and when it is adsorbed into a sandstone rock. We intend to extend this work to a number of carbonate rocks and shales in the future, and also to 10mm diameter samples, in a compact specially designed compact NMR Spectrometer (Figure 1) to which we are adding an NMR Probe with a useful variable-temperature capability, to give information on the rock pore dimensions, when there are liquids in the pores.