China possesses abundant shale oil resources, which, despite their overall low maturity, hold significant development potential. In situ conversion technology is the key to the efficient development of these medium-low maturity shale oil resources. Research in this area is a focal point in the oil and gas sector. Studying the phase behavior evolution of organic components during the heating process is crucial for both laboratory simulation and guiding extraction operations. However, comprehensive research methodologies specifically targeting phase behavior evolution during in situ conversion remain scarce, with no mature approach established. This paper begins by reviewing previous explorations and studies on predicting the phase behavior of oil and gas in low-maturity source rocks, detailing the principles, technical key points, and application cases of the Phase Kinetics method, as well as the advantages and improvements of the PhaseSnapShot method. Building upon the previously proposed two methods and considering the reservoir characteristics and hydrocarbon generation features of medium-low maturity shale oil, this paper introduces suitable hydrocarbon generation thermal simulation experiments, pyrolysis product analysis techniques, and equations of state for simulating the in situ conversion process. Finally, it proposes a research methodology for predicting phase behavior tailored to the in situ conversion of medium-low maturity shale oil.
Zhang et al. (2026) studied this question.