Oil shale blocks were cored to suitable dimensions (nominally 2.5 cm diameter and 1 cm thick). Specific gravity measurements were then carried out on these cylindrical cores to determine the organic content. Selected samples were also assayed at Laramie Energy Technology Center, WY, by the pulsed NMR technique. Oil yields obtained by the two methods on identical cores were in agreement with the limits of experimental error (vide infra). The cored shale samples were crushed to particles which passed through 100-mesh sieves. Ten to fifteen milligram batches of these crushed shale particles were then subjected to enthalpy measurements in the differential scanning calorimetry assembly. A sample of kerogen concentrate was obtained from Laramie Energy Technology Center. DSC measurements were carried out on a DuPont 990 thermal analysis system fitted with the DSC accessory module. All measurements were carried out in a flowing atmosphere of prepurified N/sub 2/. A heating rate of 10/sup 0/C/min was employed for the enthalpy determinations. The fusion endotherm of zinc (mp 419.4/sup 0/C, ..delta..H/sub f/ = 27.05 cal/g) was used as the calibration standard. The linear correlation that was observed between the enthalpy of decomposition of the organic matter (..delta..H) and oil yields for Green river oil shales suggests that this technique might be useful as a rapid screening tool for resource evaluation of an oil shale deposit.
