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The work objective was an analysis for the petroleum prospectivity of a core from the Marcellus Formation of Western Pennsylvania, USA. In accordance with the investigation results, two sample groups were delineated based on TOC and S1free oil measurements of the analyzed core and the most prospective interval for further development was marked out. Core analysis on a Marcellus TST sequence overlain by undetermined sequence Marcellus core was done using pyrolysis and SEM XRF measurements together with GR (Gamma Ray), ChemoGR (calculated from Potassium, Thorium and Uranium), Porosity and PHIE (Effective Porosity) logging. Oil saturation was measured using both Classical Pyrolysis and HAWK-PAM methods. HAWK Petroleum Assessment MethodTM is advanced multiramp/multizone pyrolysis method that utilizes five zones using multiple ramp and isotherm routines assigned during a single sample analysis. A ramp rate of 25°C is utilized to generate five petroleum peaks – four on oil fractions and one on kerogen. The efficiency of the HAWK-PAM pyrolysis method is shown for determination of the sweet spot intervals that is particularly important for the development of hard-to-recover unconventional reservoirs like the Marcellus Formation in USA or the Bazhenov Formation in Russia.

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Our pursuit of "Source Rock" understanding began with confirmation of hydrocarbon generation from kerogen with the influence of temperature and pressure (Hunt, 1962; Philipi 1965; Louis and Tissot, 1967;Giraud, 1970 andTissot et al, 1971). The published origins of programmed-temperature source rock pyrolysis can be tracked back as far as (McIver, 1967; Gransch and Eisma, 1970; and provide key insights into fundamentals of hydrocarbon generation via burial. The most important of which was the identification of two distinct hydrocarbon peaks (Barker, 1974) from organic rich rocks over the range of 100°C -550°C. And eventually significant differences in hydrocarbon composition generated for different kerogen specimens (from different geologic time periods with different burial history). Harwood (1977) experimented with higher volatization temperatures at atmospheric pressures and determined that "higher temperature rather than longer reaction times at lower temperatures is the practical way to attain high carbonization rates in the laboratory." This advancement lead to analysis in a matter of hours rather than days and further solidified pyrolysis as a routine method for kerogen maturation/conversion studies.Espitalie et al (1977) finalized the traditional laboratory method still used with Rock Eval®, Source Rock Analyzer® and HAWK SM for routine pyrolysis today. The temperature profile for this pyrolysis method (illustrated in Fig. 1) begins with a 300°C oven isotherm temperature for three minutes. We believe this temperature was chosen based on the work of , but little to no background was provided by Espitalie. The initial isotherm is followed by pyrolyzing the sample at 25°C/ min from 300°C to 550°C (or higher in some cases). All temperatures shown from initial work of Espitalie et al. (1977) are nominal. Burnham (1987) demonstrates that the lower the ramp rate, the lower the measured Tmax value for the same rock sample when a single point calibration is utilized across the various ramp rates. A caveat that is addressed through proper calibration in response to modified ramp rates and repeatable standard results collected throughout the sequence every 5-10 samples)