Using of pyrolysis data in the analysis of the oil-and-gas prospectivity of a formation as part of a studies complex on the example of the Marcellus formation

Abstract

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.